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  • Sending multiple requests simultaneously to the Server using Selenium with Java

    - by gagneet
    I wish to send multiple requests to the server, simultaneously. The problem statement will be: Read a text file containing multiple URL’s. Open each URL in the web browser. Collect the Cookie information for each call, and store it to a file. Send another call: http://myserver.com:1111/cookie?out=text Store the output (body text) of this file to a separate file for each call made in 4 Open the next URL in the text file given in 1 and repeat steps 1-6. The above is to be run with multi-threading, so that I can send around 5-10 URL requests simultaneously. I have implemented something in Selenium using Java, but have not been able to do the multi-threading approach. Code is given below: package com.cookie.selenium; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import com.thoughtworks.selenium.*; public class ReadURL extends SeleneseTestCase { public void setUp() throws Exception { setUp("http://www.myserver.com/", "*chrome"); } public static void main(String args[]) { Selenium selenium = new DefaultSelenium("localhost", 4444, "*chrome", "http://myserver"); selenium.start(); selenium.setTimeout("30000000"); try { BufferedReader inputfile = new BufferedReader(new FileReader("C:\\url.txt")); BufferedReader cookietextfile = new BufferedReader(new FileReader("C:\\text.txt")); BufferedWriter cookiefile = new BufferedWriter(new FileWriter("C:\\cookie.txt")); BufferedWriter outputfile = null; String str; String cookiestr = "http://myserver.com:1111/cookie?out=text"; String filename = null; int i = 0; while ((str = inputfile.readLine()) != null) { selenium.createCookie("T=222redHyt345&f=5&r=fg&t=100",""); selenium.open( str ); selenium.waitForPageToLoad("120000"); String urlcookie = selenium.getCookie(); System.out.println( "URL :" + str ); System.out.println( "Cookie :" + urlcookie ); cookiefile.write( urlcookie ); cookiefile.newLine(); selenium.open( cookiestr ); selenium.waitForPageToLoad("120000"); String bodytext = selenium.getBodyText(); System.out.println("Body Text :" + bodytext); filename = "C:\\cookies\\" + i + ".txt"; outputfile = new BufferedWriter(new FileWriter( filename )); outputfile.write( bodytext ); outputfile.newLine(); i++; } inputfile.close(); outputfile.close(); cookiefile.close(); selenium.stop(); } catch (IOException e) { } } } What basically I am trying to do here is, open the first set of URL from a text file (which has list given of all the URL's i wish to open). Then when I capture the cookie information from here and store it, I open another window to output all the cookie information for that server to my browser window. This works fine when I do outside of Selenium code, but when I do it within the above code, it opens a "Save As..." popup and my tests stop. :-( I wish to save the contents of that second call to a new file, but have not been able to do the same. Also, if I have to send multiple such requests to the server, how would that be possible in Java using a Selenium Framework. Currently, I am opening multiple instances of the framework and running them with different parameters :-(

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  • How do I code this relationship in SQLAlchemy?

    - by Martin Del Vecchio
    I am new to SQLAlchemy (and SQL, for that matter). I can't figure out how to code the idea I have in my head. I am creating a database of performance-test results. A test run consists of a test type and a number (this is class TestRun below) A test suite consists the version string of the software being tested, and one or more TestRun objects (this is class TestSuite below). A test version consists of all test suites with the given version name. Here is my code, as simple as I can make it: from sqlalchemy import * from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import relationship, backref, sessionmaker Base = declarative_base() class TestVersion (Base): __tablename__ = 'versions' id = Column (Integer, primary_key=True) version_name = Column (String) def __init__ (self, version_name): self.version_name = version_name class TestRun (Base): __tablename__ = 'runs' id = Column (Integer, primary_key=True) suite_directory = Column (String, ForeignKey ('suites.directory')) suite = relationship ('TestSuite', backref=backref ('runs', order_by=id)) test_type = Column (String) rate = Column (Integer) def __init__ (self, test_type, rate): self.test_type = test_type self.rate = rate class TestSuite (Base): __tablename__ = 'suites' directory = Column (String, primary_key=True) version_id = Column (Integer, ForeignKey ('versions.id')) version_ref = relationship ('TestVersion', backref=backref ('suites', order_by=directory)) version_name = Column (String) def __init__ (self, directory, version_name): self.directory = directory self.version_name = version_name # Create a v1.0 suite suite1 = TestSuite ('dir1', 'v1.0') suite1.runs.append (TestRun ('test1', 100)) suite1.runs.append (TestRun ('test2', 200)) # Create a another v1.0 suite suite2 = TestSuite ('dir2', 'v1.0') suite2.runs.append (TestRun ('test1', 101)) suite2.runs.append (TestRun ('test2', 201)) # Create another suite suite3 = TestSuite ('dir3', 'v2.0') suite3.runs.append (TestRun ('test1', 102)) suite3.runs.append (TestRun ('test2', 202)) # Create the in-memory database engine = create_engine ('sqlite://') Session = sessionmaker (bind=engine) session = Session() Base.metadata.create_all (engine) # Add the suites in version1 = TestVersion (suite1.version_name) version1.suites.append (suite1) session.add (suite1) version2 = TestVersion (suite2.version_name) version2.suites.append (suite2) session.add (suite2) version3 = TestVersion (suite3.version_name) version3.suites.append (suite3) session.add (suite3) session.commit() # Query the suites for suite in session.query (TestSuite).order_by (TestSuite.directory): print "\nSuite directory %s, version %s has %d test runs:" % (suite.directory, suite.version_name, len (suite.runs)) for run in suite.runs: print " Test '%s', result %d" % (run.test_type, run.rate) # Query the versions for version in session.query (TestVersion).order_by (TestVersion.version_name): print "\nVersion %s has %d test suites:" % (version.version_name, len (version.suites)) for suite in version.suites: print " Suite directory %s, version %s has %d test runs:" % (suite.directory, suite.version_name, len (suite.runs)) for run in suite.runs: print " Test '%s', result %d" % (run.test_type, run.rate) The output of this program: Suite directory dir1, version v1.0 has 2 test runs: Test 'test1', result 100 Test 'test2', result 200 Suite directory dir2, version v1.0 has 2 test runs: Test 'test1', result 101 Test 'test2', result 201 Suite directory dir3, version v2.0 has 2 test runs: Test 'test1', result 102 Test 'test2', result 202 Version v1.0 has 1 test suites: Suite directory dir1, version v1.0 has 2 test runs: Test 'test1', result 100 Test 'test2', result 200 Version v1.0 has 1 test suites: Suite directory dir2, version v1.0 has 2 test runs: Test 'test1', result 101 Test 'test2', result 201 Version v2.0 has 1 test suites: Suite directory dir3, version v2.0 has 2 test runs: Test 'test1', result 102 Test 'test2', result 202 This is not correct, since there are two TestVersion objects with the name 'v1.0'. I hacked my way around this by adding a private list of TestVersion objects, and a function to find a matching one: versions = [] def find_or_create_version (version_name): # Find existing for version in versions: if version.version_name == version_name: return (version) # Create new version = TestVersion (version_name) versions.append (version) return (version) Then I modified my code that adds the records to use it: # Add the suites in version1 = find_or_create_version (suite1.version_name) version1.suites.append (suite1) session.add (suite1) version2 = find_or_create_version (suite2.version_name) version2.suites.append (suite2) session.add (suite2) version3 = find_or_create_version (suite3.version_name) version3.suites.append (suite3) session.add (suite3) Now the output is what I want: Suite directory dir1, version v1.0 has 2 test runs: Test 'test1', result 100 Test 'test2', result 200 Suite directory dir2, version v1.0 has 2 test runs: Test 'test1', result 101 Test 'test2', result 201 Suite directory dir3, version v2.0 has 2 test runs: Test 'test1', result 102 Test 'test2', result 202 Version v1.0 has 2 test suites: Suite directory dir1, version v1.0 has 2 test runs: Test 'test1', result 100 Test 'test2', result 200 Suite directory dir2, version v1.0 has 2 test runs: Test 'test1', result 101 Test 'test2', result 201 Version v2.0 has 1 test suites: Suite directory dir3, version v2.0 has 2 test runs: Test 'test1', result 102 Test 'test2', result 202 This feels wrong to me; it doesn't feel right that I am manually keeping track of the unique version names, and manually adding the suites to the appropriate TestVersion objects. Is this code even close to being correct? And what happens when I'm not building the entire database from scratch, as in this example. If the database already exists, do I have to query the database's TestVersion table to discover the unique version names? Thanks in advance. I know this is a lot of code to wade through, and I appreciate the help.

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  • java gui changing picture causes heapspace error

    - by pie154
    I have a java programme than when a button is clicked it updates the image on screen to the according image. this will work for the first 15 or so clicks then it causes a java heapspace error. I think it is because of the way I am updating the jpanel that contains the bufferedimage but not sure what the reason is. My code to get make the JPanel contain the new image is, public class extraScreenPanel { static JPanel screenPanel = new JPanel(new BorderLayout()); public static JPanel extraScreenPanel(int dispNum) { JLabel label = new JLabel("" + dispNum + ""); label.setPreferredSize(new Dimension(800, 600)); //label.setUI( new VerticalLabelUI(true) ); label.setVerticalAlignment( SwingConstants.TOP ); screenPanel = imgDisp(dispNum); label.setForeground(Color.white); label.setFont(new Font("Serif", Font.BOLD, 200)); screenPanel.add(label, BorderLayout.PAGE_END ); return screenPanel; } public static JPanel imgDisp(int picNum) { /* String url[] = new String[5000]; String part1; url[0] = "C:/PiPhotoPic/pic16.jpg"; for(Integer i=1;i<5000;i++){ if(i<10){part1 = "C:/temp/new0000000";} else if(i<100){part1 = "C:/temp/new000000";} else if(i<1000){part1 = "C:/temp/new00000";} else {part1 = "C:/temp/new00000";} String num = Integer.toString(i); url[i]= part1 + num + ".jpg"; } if(picNum<0){picNum=0;} String ref = url[picNum];*/ //this code is just to get specific ref for image location BufferedImage loadImg = loadImage(ref); JImagePanel panel = new JImagePanel(loadImg, 0, 0); panel.setPreferredSize(new Dimension(800, 600)); return panel; } public static class JImagePanel extends JPanel{ private BufferedImage image; int x, y; public JImagePanel(BufferedImage image, int x, int y) { super(); this.image = image; this.x = x; this.y = y; } @Override protected void paintComponent(Graphics g) { super.paintComponent(g); g.drawImage(image, x, y, null); } } public static BufferedImage loadImage(String ref) { BufferedImage bimg = null; try { bimg = javax.imageio.ImageIO.read(new File(ref)); } catch (Exception e) { e.printStackTrace(); } BufferedImage bimg2 = resize(bimg,800,600); return bimg2; } public static BufferedImage resize(BufferedImage img, int newW, int newH) { int w = img.getWidth(); int h = img.getHeight(); BufferedImage dimg = dimg = new BufferedImage(newW, newH, img.getType()); Graphics2D g = dimg.createGraphics(); g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR); g.drawImage(img, 0, 0, newW, newH, 0, 0, w, h, null); g.dispose(); return dimg; } } And the code that updates my gui is, it works by removing the panel from its containg panel and then readding it to it. picPanel = imgDisp.imgDisp(num); repaintPicPanel(); public static void repaintPicPanel() { picPanel.removeAll(); menuPanel.remove(picPanel);; menuPanel.add(picPanel, BorderLayout.LINE_START); }

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  • Problem with NHibernate

    - by Bernard Larouche
    I am trying to get a list of Products that share the Category. NHibernate returns no product which is wrong. Here is my Criteria API method : public IList<Product> GetProductForCategory(string name) { return _session.CreateCriteria(typeof(Product)) .CreateCriteria("Categories") .Add(Restrictions.Eq("Name", name)) .List<Product>(); } Here is my HQL method : public IList<Product> GetProductForCategory(string name) { return _session.CreateQuery("select from Product p, p.Categories.elements c where c.Name = :name").SetString("name",name).List<Product>(); } Both methods return no product when they should return 2 products. Here is the Mapping for the Product class : <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="CBL.CoderForTraders.DomainModel" namespace="CBL.CoderForTraders.DomainModel"> <class name="Product" table="Products" > <id name="_persistenceId" column="ProductId" type="Guid" access="field" unsaved-value="00000000-0000-0000-0000-000000000000"> <generator class="assigned" /> </id> <version name="_persistenceVersion" column="RowVersion" access="field" type="int" unsaved-value="0" /> <property name="Name" column="ProductName" type="String" not-null="true"/> <property name="Price" column="BasePrice" type="Decimal" not-null="true" /> <property name="IsTaxable" column="IsTaxable" type="Boolean" not-null="true" /> <property name="DefaultImage" column="DefaultImageFile" type="String"/> <bag name="Descriptors" table="ProductDescriptors"> <key column="ProductId" foreign-key="FK_Product_Descriptors"/> <one-to-many class="Descriptor"/> </bag> <bag name="Categories" table="Categories_Products" > <key column="ProductId" foreign-key="FK_Products_Categories"/> <many-to-many class="Category" column="CategoryId"></many-to-many> </bag> <bag name="Orders" generic="true" table="OrderProduct" > <key column="ProductId" foreign-key="FK_Products_Orders"/> <many-to-many column="OrderId" class="Order" /> </bag> </class> </hibernate-mapping> And finally the mapping for the Category class : <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="CBL.CoderForTraders.DomainModel" namespace="CBL.CoderForTraders.DomainModel" default-access="field.camelcase-underscore" default-lazy="true"> <class name="Category" table="Categories" > <id name="_persistenceId" column="CategoryId" type="Guid" access="field" unsaved-value="00000000-0000-0000-0000-000000000000"> <generator class="assigned" /> </id> <version name="_persistenceVersion" column="RowVersion" access="field" type="int" unsaved-value="0" /> <property name="Name" column="Name" type="String" not-null="true"/> <property name="IsDefault" column="IsDefault" type="Boolean" not-null="true" /> <property name="Description" column="Description" type="String" not-null="true" /> <many-to-one name="Parent" column="ParentID"></many-to-one> <bag name="SubCategories" inverse="true"> <key column="ParentID" foreign-key="FK_Category_ParentCategory" /> <one-to-many class="Category"/> </bag> <bag name="Products" table="Categories_Products"> <key column="CategoryId" foreign-key="FK_Categories_Products" /> <many-to-many column="ProductId" class="Product"></many-to-many> </bag> </class> </hibernate-mapping> Can you see what could be the problem ?

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  • ValidationProperty not returning entered value for textbox in custom ontrol

    - by nat
    hi I have a custom control, (relevant code at the bottom) it consists of some text/links and a hidden textbox (rather than a hidden input). when rendered, the user via another dialog and some JS sets the value of the textbox to an integer and clicks submit on the form. i am trying to assure that the user has entered a number (via the JS) and that the textbox is not still set to its default of "0" the requiredfieldvalidator works just fine, if i dont change the value it spots it on the client and fills the validation summary on the page with the appropriate message. unfortunately when i do fill the textbox, the validator also rejests the post as the controls textbox text value is still set to "0", even though on the form it has changed. clearly i am doing something wrong.. but cant work out what it is? could someone enlighten me please, this is driving me potty if i step through the code, when the get of the mediaidtext is hit,the findcontrol finds does not the textbox, if i inspect the controls collection however i can find the textbox, but its value is still "0" it also seems that when findcontrol is called, the createchildcontrols is called again - thus resetting the value back to "0" there.. ! how can i ever assure the control realises that the textbox value has changed? many thanks code below nat [ValidationProperty("MediaIdText")] public class MediaLibraryFileControl: CompositeControl { private int mediaId = 0; public int MediaId { get { return mediaId; } set { mediaId = value; } } public string MediaIdText { get { string txt = "0"; Control ctrl = this.FindControl(this.UniqueID+ "_hidden"); try { txt = ((TextBox)ctrl).Text; MediaId = Convert.ToInt32(txt); } catch { MediaId = 0; } return txt; } } protected override void CreateChildControls() { this.Controls.Add(new LiteralControl("<span>")); this.Controls.Add(new LiteralControl("<span id=\"" + TextControlName + "\">" + getMediaDetails() + "</span>")); TextBox tb = new TextBox(); tb.Text = this.MediaId.ToString(); tb.ID = this.UniqueID + "_hidden"; tb.CssClass = "hidden"; this.Controls.Add(tb); if (Select == true) { this.Controls.Add(new LiteralControl(string.Format("&nbsp;[<a href=\"javascript:{0}(this,'{1}','{2}')\" class=\"select\">{3}</a>]", dialog, this.UniqueID, this.categoryId, "select"))); this.Controls.Add(new LiteralControl(string.Format("&nbsp;[<a href=\"javascript:{0}(this,'{1}')\" class=\"select\">{2}</a>]", clearDialog, this.ID, "clear"))); } this.Controls.Add(new LiteralControl("</span>")); } protected virtual string getMediaDetails() { //... return String.Empty; } } this is the code adding the validationcontrol the editcontrol is the instance of the control above public override Control RenderValidationControl(Control editControl) { Control ctrl = new PlaceHolder(); RequiredFieldValidator req = new RequiredFieldValidator(); req.ID = editControl.ClientID + "_validator"; req.ControlToValidate = editControl.ID; req.Display = ValidatorDisplay.None; req.InitialValue = "0"; req.EnableClientScript = false; req.ErrorMessage = "control cannot be blank"; ctrl.Controls.Add(req); return ctrl; }

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  • How to prevent client from accessing JSP page

    - by Ali Bassam
    In my web application, I use the .load() function in JQuery, to load some JSP pages inside a DIV. $("#myDiv").load("chat.jsp"); In chat.jsp, no Java codes is executed unless this client has Logged in, means, I check the session. String sessionId = session.getAttribute("SessionId"); if(sessionId.equals("100")){ //execute codes }else{ //redirect to log in page } Those java codes that will be executed, they will out.println(); some HTML elements. I don't want the client to write /chat.jsp in the browser to access this page, as it will look bad, and the other stuff in the main page won't be there, and this could do a harm to the web app security. How can I restrict someone from accessing chat.jsp directly, but yet keep it accessible via .load() ? UPDATE: JavaDB is a class that I made, it connects me to the Database. This is chat.jsp <body> <% String userId = session.getAttribute("SessionId").toString(); if (userId != null) { String roomId = request.getParameter("roomId"); String lastMessageId = request.getParameter("lastMessageId"); JavaDB myJavaDB = new JavaDB(); myJavaDB.Connect("Chat", "chat", "chat"); Connection conn = myJavaDB.getMyConnection(); Statement stmt = conn.createStatement(); String lastId = ""; int fi = 0; ResultSet rset = stmt.executeQuery("select message,message_id,first_name,last_name from users u,messages m where u.user_id=m.user_id and m.message_id>" + lastMessageId + " and room_id=" + roomId + " order by m.message_id asc"); while (rset.next()) { fi = 1; lastId = rset.getString(2); %> <div class="message"> <div class="messageSender"> <%=rset.getString(3) + " " + rset.getString(4)%> </div> <div class="messageContents"> <%=rset.getString(1)%> </div> </div> <% } %> <div class="lastId"> <% if (fi == 1) {%> <%=lastId%> <% } else {%> <%=lastMessageId%> <% }%></div> <% if (fi == 1) {%> <div class="messages"> </div> <% } } else { response.sendRedirect("index.jsp"); }%> </body> Guys I don't know what Filter means. UPDATE If I decided to send a parameter that tells me that this request came from Jquery. .load("chat.jsp",{ jquery : "yes" }); And then check it in chat.jsp String yesOrNo = request.getParameter("jquery"); Then they can simply hack this by using this URL. /chat.jsp?jquer=yes or something like that.. UPDATE I tried Maksim's advice, I got this when I tried to access chat.jsp. Is this the desired effect?

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  • Using GA in GUI

    - by AlexT
    Sorry if this isn't clear as I'm writing this on a mobile device and I'm trying to make it quick. I've written a basic Genetic Algorithm with a binary encoding (genes) that builds a fitness value and evolves through several iterations using tournament selection, mutation and crossover. As a basic command-line example it seems to work. The problem I've got is with applying a genetic algorithm within a GUI as I am writing a maze-solving program that uses the GA to find a method through a maze. How do I turn my random binary encoded genes and fitness function (add all the binary values together) into a method to control a bot around a maze? I have built a basic GUI in Java consisting of a maze of labels (like a grid) with the available routes being in blue and the walls being in black. To reiterate my GA performs well and contains what any typical GA would (fitness method, get and set population, selection, crossover, etc) but now I need to plug it into a GUI to get my maze running. What needs to go where in order to get a bot that can move in different directions depending on what the GA says? Rough pseudocode would be great if possible As requested, an Individual is built using a separate class (Indiv), with all the main work being done in a Pop class. When a new individual is instantiated an array of ints represent the genes of said individual, with the genes being picked at random from a number between 0 and 1. The fitness function merely adds together the value of these genes and in the Pop class handles selection, mutation and crossover of two selected individuals. There's not much else to it, the command line program just shows evolution over n generations with the total fitness improving over each iteration. EDIT: It's starting to make a bit more sense now, although there are a few things that are bugging me... As Adamski has suggested I want to create an "Agent" with the options shown below. The problem I have is where the random bit string comes into play here. The agent knows where the walls are and has it laid out in a 4 bit string (i.e. 0111), but how does this affect the random 32 bit string? (i.e. 10001011011001001010011011010101) If I have the following maze (x is the start place, 2 is the goal, 1 is the wall): x 1 1 1 1 0 0 1 0 0 1 0 0 0 2 If I turn left I'm facing the wrong way and the agent will move completely off the maze if it moves forward. I assume that the first generation of the string will be completely random and it will evolve as the fitness grows but I don't get how the string will work within a maze. So, to get this straight... The fitness is the result of when the agent is able to move and is by a wall. The genes are a string of 32 bits, split into 16 sets of 2 bits to show the available actions and for the robot to move the two bits need to be passed with four bits from the agent showings its position near the walls. If the move is to go past a wall the move isn't made and it is deemed invalid and if the move is made and if a new wall is found then the fitness goes up. Is that right?

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  • Launching a file using ACTION_VIEW Intent Action

    - by Sneha
    I have the following code to launch a file : try { path = fileJsonObject.getString("filePath"); if (path.indexOf("/") == 0) { path = path.substring(1, path.length()); } path = root + path; final File fileToOpen = new File(path); if (fileToOpen.exists()) { if (fileToOpen.isFile()) { Intent myIntent = new Intent(android.content.Intent.ACTION_VIEW); myIntent.setData(Uri.parse(path)); final String pathToCheck = new String(path); pathToCheck.toLowerCase(); if (pathToCheck.endsWith(".wav") || pathToCheck.endsWith(".ogg") || pathToCheck.endsWith(".mp3") || pathToCheck.endsWith(".mid") || pathToCheck.endsWith(".midi") || pathToCheck.endsWith(".amr")) { myIntent.setType("audio/*"); } else if (pathToCheck.endsWith(".mpg") || pathToCheck.endsWith(".mpeg") || pathToCheck.endsWith(".3gp") || pathToCheck.endsWith(".mp4")) { myIntent.setType("video/*"); } else if (pathToCheck.endsWith(".jpg") || pathToCheck.endsWith(".jpeg") || pathToCheck.endsWith(".gif") || pathToCheck.endsWith(".png") || pathToCheck.endsWith(".bmp")) { myIntent.setType("image/*"); } else if (pathToCheck.endsWith(".txt") || pathToCheck.endsWith(".csv") || pathToCheck.endsWith(".xml")) { Log.i("txt","Text fileeeeeeeeeeeeeeeeeeeeeeeeee"); myIntent.setType("text/*"); } else if (pathToCheck.endsWith(".gz") || pathToCheck.endsWith(".rar") || pathToCheck.endsWith(".zip")) { myIntent.setType("package/*"); } else if (pathToCheck.endsWith(".apk")) { myIntent.setType("application/vnd.android.package-archive"); } ((Activity) context).startActivityForResult(myIntent, RequestCodes.LAUNCH_FILE_CODE); } else { errUrl = resMsgHandler.errMsgResponse(fileJsonObject, "Incorrect path provided. please give correct path of file"); return errUrl; } } else { errUrl = resMsgHandler.errMsgResponse(fileJsonObject,"Incorrect path provided. please give correct path of file"); return errUrl; } } catch (Exception e) { e.printStackTrace(); Log.i("err","Unable to launch file" + " " + e.getMessage()); errUrl = resMsgHandler.errMsgResponse(fileJsonObject, "Unable to launch file" + " " + e.getMessage()); return errUrl; } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { // TODO Auto-generated method stub super.onActivityResult(requestCode, resultCode, data); try { if (requestCode == RequestCodes.LAUNCH_FILE_CODE) { if (resultCode == RESULT_CANCELED) { Log.i("err","errrrrrrrrrrrrrrrrrrrrrrrrrrrrrr"); String errUrl = responseMsgHandler.errMsgResponse(FileHandler.fileJsonObject, "Unable to launch file"); mWebView.loadUrl(errUrl); } else if (resultCode == RESULT_OK) { String successUrl = responseMsgHandler.launchfileResponse(FileHandler.fileJsonObject); mWebView.loadUrl(successUrl); } Amd the result ctrl is at "if (resultCode == RESULT_CANCELED)". So how to successfully launch this? May be in short i am doing this: final File fileToOpen = new File(path); if (fileToOpen.exists()) { if (fileToOpen.isFile()) { Intent myIntent = new Intent(android.content.Intent.ACTION_VIEW); myIntent.setData(Uri.parse(path)); if (pathToCheck.endsWith(".txt") || pathToCheck.endsWith(".csv") || pathToCheck.endsWith(".xml")) { Log.i("txt","Text fileeeeeeeeeeeeeeeeeeeeeeeeee"); myIntent.setType("text/*"); startActivityForResult(myIntent, RequestCodes.LAUNCH_FILE_CODE); and @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { // TODO Auto-generated method stub super.onActivityResult(requestCode, resultCode, data); if (requestCode == RequestCodes.LAUNCH_FILE_CODE) { if (resultCode == RESULT_CANCELED) { Log.i ("err","errrrrrrrrrrrrrrrrrrrrrrrrrrrrrr"); String errUrl = responseMsgHandler.errMsgResponse(FileHandler.fileJsonObject, "Unable to launch file"); mWebView.loadUrl(errUrl); } else if (resultCode == RESULT_OK) { String successUrl = responseMsgHandler.launchfileResponse(FileHandler.fileJsonObject); mWebView.loadUrl(successUrl); } My err log: 04-04 10:53:57.077: ERROR/AndroidRuntime(6861): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tf.thinkdroid.sstablet/com.tf.thinkdroid.write.editor.WriteEditorActivity}: java.lang.NullPointerException 04-04 10:53:57.077: ERROR/AndroidRuntime(6861): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 04-04 10:53:57.077: ERROR/AndroidRuntime(6861): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) ..... 04-04 10:53:57.077: ERROR/AndroidRuntime(6861): Caused by: java.lang.NullPointerException 04-04 10:53:57.077: ERROR/AndroidRuntime(6861): at com.tf.thinkdroid.common.app.TFActivity.storeDataToFileIfNecessary(Unknown Source) 04-04 10:53:57.077: ERROR/AndroidRuntime(6861): at com.tf.thinkdroid.common.app.TFActivity.onPostCreate(Unknown Source) ... Thanks Sneha

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  • File observer problem

    - by Nemat
    Hi, I want to listen to the changes occured in file system.I am using FileObserver.Here is my code: Code: class MyDirObserver extends FileObserver { String superPath; public MyDirObserver(String path) { super(path, ALL_EVENTS); this.superPath=path; } public void onEvent(int event, String path) { Log.e("onEvent of Directory", "=== onEvent ==="); try{ _Dump("dir", event, path,superPath); } catch(NullPointerException ex) { Log.e("ERROR","I am getting error"); } } } private void _Dump(final String tag, int event, String path,String superPath) { Log.d(tag, "=== dump begin ==="); Log.d(tag, "path=" + path); Log.d(tag,"super path="+superPath); Log.d(tag, "event list:"); if ((event & FileObserver.OPEN) != 0) { Log.d(tag, " OPEN"); } if ((event & FileObserver.CLOSE_NOWRITE) != 0) { Log.d(tag, " CLOSE_NOWRITE"); } if ((event & FileObserver.CLOSE_WRITE) != 0) { Log.d(tag, " CLOSE_WRITE"); Log.i("NEWFILEOBSERVER","File is Modified"); if(path!=null) { Log.d("---------FilePath",superPath+path); } } if ((event & FileObserver.CREATE) != 0) { isCreate=true; Log.i("NEWFILEOBSERVER","File is Created "); if(path!=null) { Log.d("---------FilePath",superPath+path); } Log.d(tag, " CREATE"); } if ((event & FileObserver.DELETE) != 0) { Log.i("NEWFILEOBSERVER","File is deleted"); if(path!=null) { Log.d("---------FilePath",superPath+path); } // startMyActivity("A new file is deleted thats="+superPath); Log.d(tag, " DELETE"); } if ((event & FileObserver.DELETE_SELF) != 0) { Log.d(tag, " DELETE_SELF"); } if ((event & FileObserver.ACCESS) != 0) { Log.d(tag, " ACCESS"); } if ((event & FileObserver.MODIFY) != 0) { if(!isModified) isModified=true; if(isModified && isOpen) isAgainModified=true; Log.d(tag, " MODIFY"); } if ((event & FileObserver.MOVED_FROM) != 0) { Log.d(tag, " MOVED_FROM"); if(path!=null) { Log.d("---------FilePath",superPath+path); } } if ((event & FileObserver.MOVED_TO) != 0) { Log.d(tag, " MOVED_TO"); if(path!=null) { Log.d("---------FilePath",superPath+path); } } if ((event & FileObserver.MOVE_SELF) != 0) { Log.d(tag, " MOVE_SELF"); } if ((event & FileObserver.ATTRIB) != 0) { Log.d(tag, " ATTRIB"); } Log.d(tag, "=== dump end ==="); } it stops after some time.I dont get the exact time but doesnt work always though I call startWatching() in service in a loop which runs for all the folders of sdcard and calls startWatching() for each of them. It shows unpredictable behaviour and stops listening for some folders and runs perfectly for the others. I hope you guys help me.I tried many ways but it doesnt work perfectly.Am I doing something wrong??? or there we have some other way to do this....... Please help me........I have to get this done withing few days...... Any help is appreciated!!!! Thanks in Advance Nemat

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  • Overloading stream insertion without violating information hiding?

    - by Chris
    I'm using yaml-cpp for a project. I want to overload the << and >> operators for some classes, but I'm having an issue grappling with how to "properly" do this. Take the Note class, for example. It's fairly boring: class Note { public: // constructors Note( void ); ~Note( void ); // public accessor methods void number( const unsigned long& number ) { _number = number; } unsigned long number( void ) const { return _number; } void author( const unsigned long& author ) { _author = author; } unsigned long author( void ) const { return _author; } void subject( const std::string& subject ) { _subject = subject; } std::string subject( void ) const { return _subject; } void body( const std::string& body ) { _body = body; } std::string body( void ) const { return _body; } private: unsigned long _number; unsigned long _author; std::string _subject; std::string _body; }; The << operator is easy sauce. In the .h: YAML::Emitter& operator << ( YAML::Emitter& out, const Note& v ); And in the .cpp: YAML::Emitter& operator << ( YAML::Emitter& out, const Note& v ) { out << v.number() << v.author() << v.subject() << v.body(); return out; } No sweat. Then I go to declare the >> operator. In the .h: void operator >> ( const YAML::Node& node, Note& note ); But in the .cpp I get: void operator >> ( const YAML::Node& node, Note& note ) { node[0] >> ? node[1] >> ? node[2] >> ? node[3] >> ? return; } If I write things like node[0] >> v._number; then I would need to change the CV-qualifier to make all of the Note fields public (which defeats everything I was taught (by professors, books, and experience))) about data hiding. I feel like doing node[0] >> temp0; v.number( temp0 ); all over the place is not only tedious, error-prone, and ugly, but rather wasteful (what with the extra copies). Then I got wise: I attempted to move these two operators into the Note class itself, and declare them as friends, but the compiler (GCC 4.4) didn't like that: src/note.h:44: error: ‘YAML::Emitter& Note::operator<<(YAML::Emitter&, const Note&)’ must take exactly one argument src/note.h:45: error: ‘void Note::operator(const YAML::Node&, Note&)’ must take exactly one argument Question: How do I "properly" overload the >> operator for a class Without violating the information hiding principle? Without excessive copying?

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  • Trouble with Code First DatabaseGenerated Composite Primary Key

    - by Nick Fleetwood
    This is a tad complicated, and please, I know all the arguments against natural PK's, so we don't need to have that discussion. using VS2012/MVC4/C#/CodeFirst So, the PK is based on the date and a corresponding digit together. So, a few rows created today would be like this: 20131019 1 20131019 2 And one created tomorrow: 20131020 1 This has to be automatically generated using C# or as a trigger or whatever. The user wouldn't input this. I did come up with a solution, but I'm having problems with it, and I'm a little stuck, hence the question. So, I have a model: public class MainOne { //[Key] //public int ID { get; set; } [Key][Column(Order=1)] [DatabaseGenerated(DatabaseGeneratedOption.None)] public string DocketDate { get; set; } [Key][Column(Order=2)] [DatabaseGenerated(DatabaseGeneratedOption.None)] public string DocketNumber { get; set; } [StringLength(3, ErrorMessage = "Corp Code must be three letters")] public string CorpCode { get; set; } [StringLength(4, ErrorMessage = "Corp Code must be four letters")] public string DocketStatus { get; set; } } After I finish the model, I create a new controller and views using VS2012 scaffolding. Then, what I'm doing is debugging to create the database, then adding the following instead of trigger after Code First creates the DB [I don't know if this is correct procedure]: CREATE TRIGGER AutoIncrement_Trigger ON [dbo].[MainOnes] instead OF INSERT AS BEGIN DECLARE @number INT SELECT @number=COUNT(*) FROM [dbo].[MainOnes] WHERE [DocketDate] = CONVERT(DATE, GETDATE()) INSERT INTO [dbo].[MainOnes] (DocketDate,DocketNumber,CorpCode,DocketStatus) SELECT (CONVERT(DATE, GETDATE ())),(@number+1),inserted.CorpCode,inserted.DocketStatus FROM inserted END And when I try to create a record, this is the error I'm getting: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: The object state cannot be changed. This exception may result from one or more of the primary key properties being set to null. Non-Added objects cannot have null primary key values. See inner exception for details. Now, what's interesting to me, is that after I stop debugging and I start again, everything is perfect. The trigger fired perfectly, so the composite PK is unique and perfect, and the data in other columns is intact. My guess is that EF is confused by the fact that there is seemingly no value for the PK until AFTER an insert command is given. Also, appearing to back this theory, is that when I try to edit on of the rows, in debug, I get the following error: The number of primary key values passed must match number of primary key values defined on the entity. Same error occurs if I try to pull the 'Details' or 'Delete' function. Any solution or ideas on how to pull this off? I'm pretty open to anything, even creating a hidden int PK. But it would seem redundant. EDIT 21OCT13 [HttpPost] public ActionResult Create(MainOne mainone) { if (ModelState.IsValid) { var countId = db.MainOnes.Count(d => d.DocketDate == mainone.DocketNumber); //assuming that the date field already has a value mainone.DocketNumber = countId + 1; //Cannot implicitly convert type int to string db.MainOnes.Add(mainone); db.SaveChanges(); return RedirectToAction("Index"); } return View(mainone); } EDIT 21OCT2013 FINAL CODE SOLUTION For anyone like me, who is constantly searching for clear and complete solutions. if (ModelState.IsValid) { String udate = DateTime.UtcNow.ToString("yyyy-MM-dd"); mainone.DocketDate = udate; var ddate = db.MainOnes.Count(d => d.DocketDate == mainone.DocketDate); //assuming that the date field already has a value mainone.DocketNumber = ddate + 1; db.MainOnes.Add(mainone); db.SaveChanges(); return RedirectToAction("Index"); }

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  • Undefined reference to vtable

    - by RyanG
    So, I'm getting the infamously horrible "undefined reference to 'vtable..." error for the following code (The class in question is CGameModule.) and I cannot for the life of me understand what the problem is. At first, I thought it was related to forgetting to give a virtual function a body, but as far as I understand, everything is all here. The inheritance chain is a little long, but here is the related source code. I'm not sure what other information I should provide. My code: class CGameModule : public CDasherModule { public: CGameModule(Dasher::CEventHandler *pEventHandler, CSettingsStore *pSettingsStore, CDasherInterfaceBase *pInterface, ModuleID_t iID, const char *szName) : CDasherModule(pEventHandler, pSettingsStore, iID, 0, szName) { g_pLogger->Log("Inside game module constructor"); m_pInterface = pInterface; } virtual ~CGameModule() {}; std::string GetTypedTarget(); std::string GetUntypedTarget(); bool DecorateView(CDasherView *pView) { //g_pLogger->Log("Decorating the view"); return false; } void SetDasherModel(CDasherModel *pModel) { m_pModel = pModel; } virtual void HandleEvent(Dasher::CEvent *pEvent); private: CDasherNode *pLastTypedNode; CDasherNode *pNextTargetNode; std::string m_sTargetString; size_t m_stCurrentStringPos; CDasherModel *m_pModel; CDasherInterfaceBase *m_pInterface; }; } Inherits from... class CDasherModule; typedef std::vector<CDasherModule*>::size_type ModuleID_t; /// \ingroup Core /// @{ class CDasherModule : public Dasher::CDasherComponent { public: CDasherModule(Dasher::CEventHandler * pEventHandler, CSettingsStore * pSettingsStore, ModuleID_t iID, int iType, const char *szName); virtual ModuleID_t GetID(); virtual void SetID(ModuleID_t); virtual int GetType(); virtual const char *GetName(); virtual bool GetSettings(SModuleSettings **pSettings, int *iCount) { return false; }; private: ModuleID_t m_iID; int m_iType; const char *m_szName; }; Which inherits from.... namespace Dasher { class CEvent; class CEventHandler; class CDasherComponent; }; /// \ingroup Core /// @{ class Dasher::CDasherComponent { public: CDasherComponent(Dasher::CEventHandler* pEventHandler, CSettingsStore* pSettingsStore); virtual ~CDasherComponent(); void InsertEvent(Dasher::CEvent * pEvent); virtual void HandleEvent(Dasher::CEvent * pEvent) {}; bool GetBoolParameter(int iParameter) const; void SetBoolParameter(int iParameter, bool bValue) const; long GetLongParameter(int iParameter) const; void SetLongParameter(int iParameter, long lValue) const; std::string GetStringParameter(int iParameter) const; void SetStringParameter(int iParameter, const std::string & sValue) const; ParameterType GetParameterType(int iParameter) const; std::string GetParameterName(int iParameter) const; protected: Dasher::CEventHandler *m_pEventHandler; CSettingsStore *m_pSettingsStore; }; /// @} #endif

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  • System.Threading.Timer Doesn't Trigger my TimerCallBack Delegate

    - by Tom Kong
    Hi, I am writing my first Windows Service using C# and I am having some trouble with my Timer class. When the service is started, it runs as expected but the code will not execute again (I want it to run every minute) Please take a quick look at the attached source and let me know if you see any obvious mistakes! TIA using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Diagnostics; using System.Linq; using System.ServiceProcess; using System.Text; using System.Threading; using System.IO; namespace CXO001 { public partial class Service1 : ServiceBase { public Service1() { InitializeComponent(); } /* * Aim: To calculate and update the Occupancy values for the different Sites * * Method: Retrieve data every minute, updating a public value which can be polled */ protected override void OnStart(string[] args) { Daemon(); } public void Daemon() { TimerCallback tcb = new TimerCallback(On_Tick); TimeSpan duetime = new TimeSpan(0, 0, 1); TimeSpan interval = new TimeSpan(0, 1, 0); Timer querytimer = new Timer(tcb, null, duetime, interval); } protected override void OnStop() { } static int[] floorplanids = new int[] { 115, 114, 107, 108 }; public static List<Record> Records = new List<Record>(); static bool firstrun = true; public static void On_Tick(object timercallback) { //Update occupancy data for the last minute //Save a copy of the public values to HDD with a timestamp string starttime; if (Records.Count > 0) { starttime = Records.Last().TS; firstrun = false; } else { starttime = DateTime.Today.AddHours(7).ToString(); firstrun = true; } DateTime endtime = DateTime.Now; GetData(starttime, endtime); } public static void GetData(string starttime, DateTime endtime) { string connstr = "Data Source = 192.168.1.123; Initial Catalog = Brickstream_OPS; User Id = Brickstream; Password = bstas;"; DataSet resultds = new DataSet(); //Get the occupancy for each Zone foreach (int zone in floorplanids) { SQL s = new SQL(); string querystr = "SELECT SUM(DIRECTIONAL_METRIC.NUM_TO_ENTER - DIRECTIONAL_METRIC.NUM_TO_EXIT) AS 'Occupancy' FROM REPORT_OBJECT INNER JOIN REPORT_OBJ_METRIC ON REPORT_OBJECT.REPORT_OBJ_ID = REPORT_OBJ_METRIC.REPORT_OBJECT_ID INNER JOIN DIRECTIONAL_METRIC ON REPORT_OBJ_METRIC.REP_OBJ_METRIC_ID = DIRECTIONAL_METRIC.REP_OBJ_METRIC_ID WHERE (REPORT_OBJ_METRIC.M_START_TIME BETWEEN '" + starttime + "' AND '" + endtime.ToString() + "') AND (REPORT_OBJECT.FLOORPLAN_ID = '" + zone + "');"; resultds = s.Go(querystr, connstr, zone.ToString(), resultds); } List<Record> result = new List<Record>(); int c = 0; foreach (DataTable dt in resultds.Tables) { Record r = new Record(); r.TS = DateTime.Now.ToString(); r.Zone = dt.TableName; if (!firstrun) { r.Occupancy = (dt.Rows[0].Field<int>("Occupancy")) + (Records[c].Occupancy); } else { r.Occupancy = dt.Rows[0].Field<int>("Occupancy"); } result.Add(r); c++; } Records = result; MrWriter(); } public static void MrWriter() { StringBuilder output = new StringBuilder("Time,Zone,Occupancy\n"); foreach (Record r in Records) { output.Append(r.TS); output.Append(","); output.Append(r.Zone); output.Append(","); output.Append(r.Occupancy.ToString()); output.Append("\n"); } output.Append(firstrun.ToString()); output.Append(DateTime.Now.ToFileTime()); string filePath = @"C:\temp\CXO.csv"; File.WriteAllText(filePath, output.ToString()); } } }

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  • How to get Media Picker Field via proxy record of many-to-many in orchard

    - by Sergey Schipanov
    I need to access mediapickerfield in Widget view. This field is relative to 'ActionPart'. I have a problem, when I create many-to-many relationships to display my 'ActionPart' in the widget. When I mapped many-to-many I take an 'ActionPart' and but cannot access the mediapickerfield. Records classes public class ActionPartRecord : ContentPartRecord { public virtual string Text { get; set; } public virtual double Price { get; set; } public virtual int TextPosX { get; set; } public virtual int TextPosY { get; set; } public virtual String TextSale { get; set; } public virtual int Color { get; set; } } public class ActionListRecord { public virtual int Id { get; set; } public virtual ActionPartRecord ActionPartRecord { get; set; } public virtual ActionWidgetPartRecord ActionWidgetPartRecord { get; set; } } public class ActionWidgetPartRecord : ContentPartRecord { public ActionWidgetPartRecord() { ActionList = new List<ActionListRecord>(); } public virtual IList<ActionListRecord> ActionList { get; set; } } public class ActionWidgetPart : ContentPart<ActionWidgetPartRecord> { public IEnumerable<ActionPartRecord> ActionList { get { return Record.ActionList.Select(x => x.ActionPartRecord); } } } ActionPart class public class ActionPart : ContentPart<ActionPartRecord> { public String Text { get { return Record.Text; } set { Record.Text = value; } } /*other field*/ } Migrations public int Create() { SchemaBuilder.CreateTable("ActionPartRecord", table => table .ContentPartRecord() .Column<string>("Text") .Column<double>("Price") .Column<int>("TextPosX") .Column<int>("TextPosY") .Column<string>("TextSale") .Column<int>("Color") ); ContentDefinitionManager.AlterPartDefinition("ActionPart", builder => builder .WithField("BaseImage", fieldBuilder => fieldBuilder.OfType("MediaPickerField").WithDisplayName("Action Image")) .WithField("PatternImage", fieldBuilder => fieldBuilder.OfType("MediaPickerField").WithDisplayName("Pattern Image")) .WithField("TimeExp", fieldBuilder => fieldBuilder.OfType("DateTimeField").WithDisplayName("Expecting date")) .Attachable()); ContentDefinitionManager.AlterTypeDefinition("Action", cfg => cfg .WithPart("CommonPart") .WithPart("TitlePart") .WithPart("RoutePart") .WithPart("BodyPart") .WithPart("ActionPart") .Creatable() .Indexed()); SchemaBuilder.CreateTable("ActionListRecord", table => table .Column<int>("Id", column => column.PrimaryKey().Identity()) .Column<int>("ActionPartRecord_Id") .Column<int>("ActionWidgetPartRecord_Id") ); SchemaBuilder.CreateTable("ActionWidgetPartRecord", table => table .ContentPartRecord() ); ContentDefinitionManager.AlterPartDefinition( "ActionWidgetPart", builder => builder.Attachable()); ContentDefinitionManager.AlterTypeDefinition("ActionWidget", cfg => cfg .WithPart("ActionWidgetPart") .WithPart("WidgetPart") .WithPart("CommonPart") .WithSetting("Stereotype", "Widget")); return 1; } Driver Display method protected override DriverResult Display( ActionWidgetPart part, string displayType, dynamic shapeHelper) { return ContentShape("Parts_ActionWidget", () => shapeHelper.Parts_ActionWidget( ContentPart: part, ActionList: part.ActionList)); } Widget View @foreach (var action in Model.ActionList) { <div class="item"> *How to access BaseImage Field in this row* <div class="sale-pattern"></div> <div class="container"> <div class="carousel-caption"> <h1>@action.Text</h1> <h1 class="price">@action.Price</h1> </div> </div> </div> }

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  • Mbean registered but not found in mbean Server

    - by Prisco
    I have a problem about the mbeans. I have created a simple mbean and I have registered it on the default mBeanServer that is run (Via eclipse or java -jar mbean.jar) and in the same process if I try to fouund the mbean registered with a simple query: for (ObjectInstance instance : mbs.queryMBeans(ObjectNameMbean, null)) { System.out.println(instance.toString()); } the query retuerns my mbean, but if I start another process and try to search this mbean registered the mbeas is not found! why? The approch is : (Process that is running) public static void main(String[] args) throws Exception { MBeanServer mbeanServer =ManagementFactory.getPlatformMBeanServer(); ObjectName objectName = new ObjectName(ObjectNameMbean); Simple simple = new Simple (1, 0); mbeanServer.registerMBean(simple, objectName); while (true) { wait (Is this necessary?) } } So this is the first process that is running (that has the only pourpose to registry the mbean, because there is another process that want to read these informations. So I start another process to search this mbean but nothing. I 'm not using jboss but the local Java virtual Machine but my scope is to deploy this simple application in one ejb (autostart) and another ejb will read all informations. All suggestions are really apprecciated. This example should be more useful : Object Hello: public class Hello implements HelloMBean { public void sayHello() { System.out.println("hello, world"); } public int add(int x, int y) { return x + y; } public String getName() { return this.name; } public int getCacheSize() { return this.cacheSize; } public synchronized void setCacheSize(int size) { this.cacheSize = size; System.out.println("Cache size now " + this.cacheSize); } private final String name = "Reginald"; private int cacheSize = DEFAULT_CACHE_SIZE; private static final int DEFAULT_CACHE_SIZE = 200; } Interface HelloBean (implemented by Hello) public interface HelloMBean { public void sayHello(); public int add(int x, int y); public String getName(); public int getCacheSize(); public void setCacheSize(int size); } Simple Main import java.lang.management.ManagementFactory; import java.util.logging.Logger; import javax.management.MBeanServer; import javax.management.ObjectName; public class Main { static Logger aLog = Logger.getLogger("MBeanTest"); public static void main(String[] args) { try{ MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); ObjectName name = new ObjectName("ApplicationDomain:type=Hello"); Hello mbean = new Hello(); mbs.registerMBean(mbean, name); // System.out.println(mbs.getAttribute(name, "Name")); aLog.info("Waiting forever..."); Thread.sleep(Long.MAX_VALUE); } catch(Exception x){ x.printStackTrace(); aLog.info("exception"); } } } So now I have exported this project as jar file and run it as "java -jar helloBean.jar" and by eclipse I have modified the main class to read informations of this read (Example "Name" attribute) by using the same objectname used to registry it . Main to read : public static void main(String[] args) { try{ MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); ObjectName name = new ObjectName("ApplicationDomain:type=Hello"); System.out.println(mbs.getAttribute(name, "Name")); } catch(Exception x){ x.printStackTrace(); aLog.info("exception"); } } But nothing, the bean is not found.

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  • Visual Studio reports that not all code path return a value, even though they do

    - by chris12892
    I have an API in NETMF C# that I am writing that includes a function to send an HTTP request. For those who are familiar with NETMF, this is a heavily modified version of the "webClient" example, which a simple application that demonstrates how to submit an HTTP request, and recive a response. In the sample, it simply prints the response and returns void,. In my version, however, I need it to return the HTTP response. For some reason, Visual Studio reports that not all code paths return a value, even though, as far as I can tell, they do. Here is my code... /// <summary> /// This is a modified webClient /// </summary> /// <param name="url"></param> private string httpRequest(string url) { // Create an HTTP Web request. HttpWebRequest request = HttpWebRequest.Create(url) as HttpWebRequest; // Set request.KeepAlive to use a persistent connection. request.KeepAlive = true; // Get a response from the server. WebResponse resp = request.GetResponse(); // Get the network response stream to read the page data. if (resp != null) { Stream respStream = resp.GetResponseStream(); string page = ""; byte[] byteData = new byte[4096]; char[] charData = new char[4096]; int bytesRead = 0; Decoder UTF8decoder = System.Text.Encoding.UTF8.GetDecoder(); int totalBytes = 0; // allow 5 seconds for reading the stream respStream.ReadTimeout = 5000; // If we know the content length, read exactly that amount of // data; otherwise, read until there is nothing left to read. if (resp.ContentLength != -1) { for (int dataRem = (int)resp.ContentLength; dataRem > 0; ) { Thread.Sleep(500); bytesRead = respStream.Read(byteData, 0, byteData.Length); if (bytesRead == 0) throw new Exception("Data laes than expected"); dataRem -= bytesRead; // Convert from bytes to chars, and add to the page // string. int byteUsed, charUsed; bool completed = false; totalBytes += bytesRead; UTF8decoder.Convert(byteData, 0, bytesRead, charData, 0, bytesRead, true, out byteUsed, out charUsed, out completed); page = page + new String(charData, 0, charUsed); } page = new String(System.Text.Encoding.UTF8.GetChars(byteData)); } else throw new Exception("No content-Length reported"); // Close the response stream. For Keep-Alive streams, the // stream will remain open and will be pushed into the unused // stream list. resp.Close(); return page; } } Any ideas? Thanks...

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  • jsp error plz check this code why are not insert my data into database

    - by lekhni
    <%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%> <%@ page import="java.sql.*" %> <%@ page import="java.io.*"%> <%@ page import="java.io.File"%> <%@ page import="java.util.*"%> <%@ page import="java.sql.*"%> <%@ page import="java.sql.Blob"%> <%@ page import="java.sql.PreparedStatement"%> <%@ page import="java.sql.BatchUpdateException"%> <%@ page import="javax.servlet.*"%> <%@ page import="javax.servlet.http.*"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <base href="<%=basePath%>"> <title>My JSP 'p.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <% int activityId = Integer.parseInt(request.getParameter("activityId")); String name = request.getParameter("name"); String activityType = request.getParameter("activityType"); int parentId = Integer.parseInt(request.getParameter("parentId")); String description = request.getParameter("description"); %> <% Connection conn=null; PreparedStatement pstatement = null; try{ Class.forName("com.mysql.jdbc.Driver"); conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/pol","root","1234"); Statement st=conn.createStatement(); String queryString = "INSERT INTO activity(activityId,name,activityType,parentId,description)" + " VALUES (?, ?, ?, ?, ?)"; pstatement = conn.prepareStatement(queryString); pstatement.setInt(1, activityId); pstatement.setString(2, name); pstatement.setString(3, activityType); pstatement.setInt(4, parentId); pstatement.setString(5, description); } catch (Exception ex) { out.println("Unable to connect to batabase."); } finally { pstatement.close(); conn.close(); } %> </body> </html>

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  • Java: How to check the random letters from a-z, out of 10 letters minimum 2 letter should be a vowel

    - by kalandar
    I am writing a program to validate the following scenarios: Scenario 1: I am using the Random class from java.util. The random class will generate 10 letters from a-z and within 10 letter, minimum 2 letters must be a vowels. Scenario 2: When the player 1 and player 2 form a word from A-Z, he will score some points. There will be a score for each letter. I have already assigned the values for A-Z. At the end of the game, the system should display a scores for player 1 and player 2. How do i do it? Please help. I will post my code here. Thanks a lot. =========================================== import java.util.Random; import java.util.Scanner; public class FindYourWords { public static void main(String[] args) { Random rand = new Random(); Scanner userInput = new Scanner(System.in); //==================Player object=============================================== Player playerOne = new Player(); playerOne.wordScore = 0; playerOne.choice = "blah"; playerOne.turn = true; Player playerTwo = new Player(); playerTwo.wordScore = 0; playerTwo.choice = "blah"; playerTwo.turn = false; //================== Alphabet ================================================== String[] newChars = { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z" }; //values of the 26 alphabets to be used int [] letterScore = {1,3,3,2,1,4,2,4,1,8,5,1,3,1,1,3,10,1,1,1,1,4,4,8,4,10}; // to assign score to the player1 and player 2 String[] vowel = { "a", "e", "i", "o", "u" }; // values for vowels int vow=0; System.out.println("FINDYOURWORDS\n"); int[] arrayRandom = new int[10]; //int array for word limiter String[] randomLetter = new String[10]; //storing the letters in newChars into this array //=============================================================================== boolean cont = true; while (cont) { if (playerOne.turn) { System.out.print("Letters of Player 1: "); } else if (!playerOne.turn) { System.out.print("Letters of Player 2: "); } for (int i = 0; i < arrayRandom.length; i++) { //running through the array limiter int r = rand.nextInt(newChars.length); //assigning random nums to the array of letters randomLetter[i] = newChars[r]; System.out.print(randomLetter[i]+ " "); } //input section for player System.out.println(""); System.out.println("Enter your word (or '@' to pass or '!' to quit): "); if (playerOne.turn) { playerOne.choice = userInput.next(); System.out.println(playerOne.turn); playerOne.turn = false; } else if (!playerOne.turn){ playerTwo.choice = userInput.next(); System.out.println(playerOne.turn); playerOne.turn = true; } //System.out.println(choice); String[] wordList = FileUtil.readDictFromFile("words.txt"); //Still dunno what this is for if (playerOne.choice.equals("@")) { playerOne.turn = false; } else if (playerTwo.choice.equals("@")) { playerOne.turn = true; } else if (playerOne.choice.equals("!")) { cont = false; } for (int i = 0; i < wordList.length; i++) { //System.out.println(wordList[i]); if (playerOne.choice.equalsIgnoreCase(wordList[i]) || playerTwo.choice.equalsIgnoreCase(wordList[i])){ } } } }}

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  • What am I doing wrong?, linking in C++

    - by Facon
    I'm trying to code a simple base64 encoder/decoder (to test my programming skill). I can compile it, but it doesn't link, I've this message error: C:\Documents and Settings\Facon\Escritoriog++ base64.o main.o -o prueba.exe main.o:main.cpp:(.text+0x24a): undefined reference to `Base64Encode(std::vector const&)' collect2: ld returned 1 exit status Compiler & Linker: Mingw32 3.4.5 SO: Windows XP This is my source code: base64.h: #ifndef BASE64_H #define BASE64_H #include <iostream> #include <vector> typedef unsigned char byte; std::string Base64Encode(const std::vector<byte> &array); std::vector<byte> Base64Decode(const std::string &array); #endif base64.cpp: #include "base64.h" std::string Base64Encode(std::vector<byte> &array) { const char *base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; const unsigned int size = array.size(); std::string output; for (unsigned int i = 0; (i < size); i++) { if ((size - i) > 3) { output.push_back(static_cast<char>(base64_table[array[i] >> 2])); output.push_back(static_cast<char>(base64_table[((array[i++] & 0x03) << 4) | ((array[i] & 0xF0) >> 4)])); output.push_back(static_cast<char>(base64_table[((array[i++] & 0x0F) << 2) | ((array[i] & 0xC0) >> 4)])); output.push_back(static_cast<char>(base64_table[array[i] & 0x3F])); } else if ((size - i) == 3) { output.push_back(static_cast<char>(base64_table[array[i] >> 2])); output.push_back(static_cast<char>(base64_table[((array[i++] & 0x03) << 4) | ((array[i] & 0xF0) >> 4)])); output.push_back(static_cast<char>(base64_table[(array[i] & 0x0F) << 2])); output.push_back(static_cast<char>('=')); } else if ((size - i) == 2) { output.push_back(static_cast<char>(base64_table[array[i] >> 2])); output.push_back(static_cast<char>(base64_table[(array[i] & 0x03) << 4])); output.push_back('='); output.push_back('='); } } return output; } std::vector<byte> Base64Decode(const std::string &array) // TODO { const char *base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; } main.cpp: #include <iostream> #include <vector> #include "base64.h" using namespace std; int main(int argc, char *argv[]) { const char* prueba = "sure."; vector<byte> texto; string codificado; for (unsigned int i = 0; (prueba[i] != 0); i++) { texto.push_back(prueba[i]); } codificado = Base64Encode(texto); cout << codificado; return 0; } PD: Sorry for my bad knowledge of English :P

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  • ValidationProperty not returning entered value for textbox

    - by nat
    hi I have a custom control, (relevant code at the bottom) it consists of some text/links and a hidden textbox (rather than a hidden input). when rendered, the user via another dialog and some JS sets the value of the textbox to an integer and clicks submit on the form. i am trying to assure that the user has entered a number (via the JS) and that the textbox is not still set to its default of "0" the requiredfieldvalidator works just fine, if i dont change the value it spots it on the client and fills the validation summary on the page with the appropriate message. unfortunately when i do fill the textbox, the validator also rejests the post as the controls textbox text value is still set to "0", even though on the form it has changed. clearly i am doing something wrong.. but cant work out what it is? could someone enlighten me please, this is driving me potty if i step through the code, when the get of the mediaidtext is hit,the findcontrol finds the textbox, but the value is still set to "0" many thanks code below nat [ValidationProperty("MediaIdText")] public class MediaLibraryFileControl: CompositeControl { private int mediaId = 0; public int MediaId { get { return mediaId; } set { mediaId = value; } } public string MediaIdText { get { string txt = "0"; Control ctrl = this.FindControl(this.UniqueID+ "_hidden"); try { txt = ((TextBox)ctrl).Text; MediaId = Convert.ToInt32(txt); } catch { MediaId = 0; } return txt; } } protected override void CreateChildControls() { this.Controls.Add(new LiteralControl("<span>")); this.Controls.Add(new LiteralControl("<span id=\"" + TextControlName + "\">" + getMediaDetails() + "</span>")); TextBox tb = new TextBox(); tb.Text = this.MediaId.ToString(); tb.ID = this.UniqueID + "_hidden"; tb.CssClass = "hidden"; this.Controls.Add(tb); if (Select == true) { this.Controls.Add(new LiteralControl(string.Format("&nbsp;[<a href=\"javascript:{0}(this,'{1}','{2}')\" class=\"select\">{3}</a>]", dialog, this.UniqueID, this.categoryId, "select"))); this.Controls.Add(new LiteralControl(string.Format("&nbsp;[<a href=\"javascript:{0}(this,'{1}')\" class=\"select\">{2}</a>]", clearDialog, this.ID, "clear"))); } this.Controls.Add(new LiteralControl("</span>")); } protected virtual string getMediaDetails() { //... return String.Empty; } } this is the code adding the validationcontrol the editcontrol is the instance of the control above public override Control RenderValidationControl(Control editControl) { Control ctrl = new PlaceHolder(); RequiredFieldValidator req = new RequiredFieldValidator(); req.ID = editControl.ClientID + "_validator"; req.ControlToValidate = editControl.ID; req.Display = ValidatorDisplay.None; req.InitialValue = "0"; req.EnableClientScript = false; req.ErrorMessage = "control cannot be blank"; ctrl.Controls.Add(req); return ctrl; }

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  • Servlet response wrapper has encoding problem

    - by John O
    A servlet response wrapper is being used in a Servlet Filter. The idea is that the response is manipulated, with a 'nonce' value being injected into forms, as part of defence against CSRF attacks. The web app is using UTF-8 everywhere. When the Servlet Filter is absent, no problems. When the filter is added, encoding issues occur. (It seems as if the response is reverting to 8859-1.) The guts of the code : final class CsrfResponseWrapper extends AbstractResponseWrapper { ... byte[] modifyResponse(byte[] aInputResponse){ ... String originalInput = new String(aInputResponse, encoding); String modifiedResult = addHiddenParamToPostedForms(originalInput); result = modifiedResult.getBytes(encoding); ... } ... } As I understand it, the transition between byte-land and String-land should specify an encoding. That is done here, as you can see, in two places. The value of the 'encoding' variable is 'UTF-8'; the alteration of the String itself is standard string manipulation (with a regex), and never specifies an encoding (addHiddenParamToPostedForms). Where am I in error about the encoding? EDIT: Here is the base class (sorry it's rather long): package hirondelle.web4j.security; import javax.servlet.ServletOutputStream; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpServletResponseWrapper; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.PrintWriter; /** Abstract Base Class for altering response content. (May be useful in future contexts as well. For now, keep package-private.) */ abstract class AbstractResponseWrapper extends HttpServletResponseWrapper { AbstractResponseWrapper(ServletResponse aServletResponse) throws IOException { super((HttpServletResponse)aServletResponse); fOutputStream = new ModifiedOutputStream(aServletResponse.getOutputStream()); fWriter = new PrintWriter(fOutputStream); } /** Return the modified response. */ abstract byte[] modifyResponse(byte[] aInputResponse); /** Standard servlet method. */ public final ServletOutputStream getOutputStream() { //fLogger.fine("Modified Response : Getting output stream."); if ( fWriterReturned ) { throw new IllegalStateException(); } fOutputStreamReturned = true; return fOutputStream; } /** Standard servlet method. */ public final PrintWriter getWriter() { //fLogger.fine("Modified Response : Getting writer."); if ( fOutputStreamReturned ) { throw new IllegalStateException(); } fWriterReturned = true; return fWriter; } // PRIVATE /* Well-behaved servlets return either an OutputStream or a PrintWriter, but not both. */ private PrintWriter fWriter; private ModifiedOutputStream fOutputStream; /* These items are used to implement conformance to the javadoc for ServletResponse, regarding exceptions being thrown. */ private boolean fWriterReturned; private boolean fOutputStreamReturned; /** Modified low level output stream. */ private class ModifiedOutputStream extends ServletOutputStream { public ModifiedOutputStream(ServletOutputStream aOutputStream) { fServletOutputStream = aOutputStream; fBuffer = new ByteArrayOutputStream(); } /** Must be implemented to make this class concrete. */ public void write(int aByte) { fBuffer.write(aByte); } public void close() throws IOException { if ( !fIsClosed ){ processStream(); fServletOutputStream.close(); fIsClosed = true; } } public void flush() throws IOException { if ( fBuffer.size() != 0 ){ if ( !fIsClosed ) { processStream(); fBuffer = new ByteArrayOutputStream(); } } } /** Perform the core processing, by calling the abstract method. */ public void processStream() throws IOException { fServletOutputStream.write(modifyResponse(fBuffer.toByteArray())); fServletOutputStream.flush(); } // PRIVATE // private ServletOutputStream fServletOutputStream; private ByteArrayOutputStream fBuffer; /** Tracks if this stream has been closed. */ private boolean fIsClosed = false; } }

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  • How to manipulate data after its retrieved via remote database

    - by bMon
    So I've used code examples from all over the net and got my app to accurately call a .php file on my server, retrieve the JSON data, then parse the data, and print it. The problem is that its just printing to the screen for sake of the tutorial I was following, but now I need to use that data in other places and need help figuring out that process. The ultimate goal is to return my db query with map coordinates, then plot them on a google map. I have another app in which I manually plot points on a map, so I'll be integrating this app with that once I can get my head around how to correctly manipulate the data returned. public class Remote extends Activity { /** Called when the activity is first created. */ TextView txt; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // Create a crude view - this should really be set via the layout resources // but since its an example saves declaring them in the XML. LinearLayout rootLayout = new LinearLayout(getApplicationContext()); txt = new TextView(getApplicationContext()); rootLayout.addView(txt); setContentView(rootLayout); // Set the text and call the connect function. txt.setText("Connecting..."); //call the method to run the data retreival txt.setText(getServerData(KEY_121)); } public static final String KEY_121 = "http://example.com/mydbcall.php"; private String getServerData(String returnString) { InputStream is = null; String result = ""; //the year data to send //ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); //nameValuePairs.add(new BasicNameValuePair("year","1970")); try{ HttpClient httpclient = new DefaultHttpClient(); HttpPost httppost = new HttpPost(KEY_121); HttpResponse response = httpclient.execute(httppost); HttpEntity entity = response.getEntity(); is = entity.getContent(); }catch(Exception e){ Log.e("log_tag", "Error in http connection "+e.toString()); } //convert response to string try{ BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8); StringBuilder sb = new StringBuilder(); String line = null; while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } is.close(); result=sb.toString(); }catch(Exception e){ Log.e("log_tag", "Error converting result "+e.toString()); } //parse json data try{ JSONArray jArray = new JSONArray(result); for(int i=0;i<jArray.length();i++){ JSONObject json_data = jArray.getJSONObject(i); Log.i("log_tag","longitude: "+json_data.getDouble("longitude")+ ", latitude: "+json_data.getDouble("latitude") ); //Get an output to the screen returnString += "\n\t" + jArray.getJSONObject(i); } }catch(JSONException e){ Log.e("log_tag", "Error parsing data "+e.toString()); } return returnString; } } So the code: returnString += "\n\t" + jArray.getJSONObject(i); is what is currently printing to the screen. What I have to figure out is how to get the data into something I can reference in other spots in the program, and access the individual elements ie: double longitude = jArray.getJSONObject(3).longitude; or something to that effect.. I figure the class getServerData will have to return a Array type or something? Any help is appreciated, thanks.

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  • Logcat error: "addView(View, LayoutParams) is not supported in AdapterView" in a ListView

    - by HacKreatorz
    I'm doing an aplication for Android and something I need is that it shows a list of all files and directories in the SD Card and it has to be able to move through the different directories. I found a good tutorial in anddev: http://bit.ly/h4GyFC I modified a few things so the aplication moves in the SD Card and not in Android root Directories but the rest is mostly the same. This is my xml file for the activity: <?xml version="1.0" encoding="utf-8"?> <ListView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@id/android:list" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" /> </ListView> And this is the code for the Activity: import hackreatorz.cifrador.R; import java.io.File; import java.util.ArrayList; import android.app.ListActivity; import android.content.res.Configuration; import android.os.Bundle; import android.view.View; import android.widget.ArrayAdapter; import android.widget.ListView; import android.widget.Toast; public class ArchivosSD extends ListActivity { private ArrayList<String> directoryEntries = new ArrayList<String>(); private File currentDirectory = new File("/sdcard/"); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); browseToSD(); } @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); } private void browseToSD() { browseTo(new File("/sdcard/")); } private void upOneLevel() { if(this.currentDirectory.getParent() != null) this.browseTo(this.currentDirectory.getParentFile()); } private void browseTo(final File directory) { if (directory.isDirectory()) { this.currentDirectory = directory; fill(directory.listFiles()); } else { Toast.makeText(ArchivosSD.this, this.directoryEntries.get(this.getSelectedItemPosition()), Toast.LENGTH_SHORT).show(); } } private void fill(File[] files) { this.directoryEntries.clear(); this.directoryEntries.add(getString(R.string.current_dir)); if(this.currentDirectory.getParent() != null) this.directoryEntries.add(getString(R.string.up_one_level)); int currentPathStringLength = (int) this.currentDirectory.getAbsoluteFile().length(); for (File file : files) { this.directoryEntries.add(file.getAbsolutePath().substring(currentPathStringLength)); } setListAdapter(new ArrayAdapter<String>(this, R.layout.archivos_sd, this.directoryEntries)); } @Override protected void onListItemClick(ListView l, View v, int position, long id) { int selectionRowID = (int) this.getSelectedItemPosition(); String selectedFileString = this.directoryEntries.get(selectionRowID); if (selectedFileString.equals(".")) { this.browseToSD(); } else if(selectedFileString.equals("..")) { this.upOneLevel(); } else { File clickedFile = null; clickedFile = new File(this.currentDirectory.getAbsolutePath() + this.directoryEntries.get(selectionRowID)); if(clickedFile != null) this.browseTo(clickedFile); } } } I don't get any errores in Eclipse, but I get a Force Close when running the aplication on my phone and when I look at Logcat I see the following: 01-01 23:30:29.858: ERROR/AndroidRuntime(14911): FATAL EXCEPTION: main *01-01 23:30:29.858: ERROR/AndroidRuntime(14911): java.lang.UnsupportedOperationException: addView(View, LayoutParams) is not supported in AdapterView* I don't have a clue what to do, I've looked up in Google and I didn't find anything and I did the same at stackoverflow. This is my first aplication in Java and for Android so I'm a real n00b and if the answer was there, I didn't understand it so I would really apreciate if you could explain what I should do to fix this error and why. Thanks for everything in advanced.

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  • C# ambiguity in Func + extension methods + lambdas

    - by Hobbes
    I've been trying to make my way through this article: http://blogs.msdn.com/wesdyer/archive/2008/01/11/the-marvels-of-monads.aspx ... And something on page 1 made me uncomfortable. In particular, I was trying to wrap my head around the Compose<() function, and I wrote an example for myself. Consider the following two Func's: Func<double, double> addTenth = x => x + 0.10; Func<double, string> toPercentString = x => (x * 100.0).ToString() + "%"; No problem! It's easy to understand what these two do. Now, following the example from the article, you can write a generic extension method to compose these functions, like so: public static class ExtensionMethods { public static Func<TInput, TLastOutput> Compose<TInput, TFirstOutput, TLastOutput>( this Func<TFirstOutput, TLastOutput> toPercentString, Func<TInput, TFirstOutput> addTenth) { return input => toPercentString(addTenth(input)); } } Fine. So now you can say: string x = toPercentString.Compose<double, double, string>(addTenth)(0.4); And you get the string "50%" So far, so good. But there's something ambiguous here. Let's say you write another extension method, so now you have two functions: public static class ExtensionMethods { public static Func<TInput, TLastOutput> Compose<TInput, TFirstOutput, TLastOutput>( this Func<TFirstOutput, TLastOutput> toPercentString, Func<TInput, TFirstOutput> addTenth) { return input => toPercentString(addTenth(input)); } public static Func<double, string> Compose<TInput, TFirstOutput, TLastOutput>(this Func<double, string> toPercentString, Func<double, double> addTenth) { return input => toPercentString(addTenth(input + 99999)); } } Herein is the ambiguity. Don't these two function have overlapping signatures? Yes. Does this even compile? Yes. Which one get's called? The second one (which clearly gives you the "wrong" result) gets called. If you comment out either function, it still compiles, but you get different results. It seems like nitpicking, but there's something that deeply offends my sensibilities here, and I can't put my finger on it. Does it have to do with extension methods? Does it have to do with lambdas? Or does it have to do with how Func< allows you to parameterize the return type? I'm not sure. I'm guessing that this is all addressed somewhere in the spec, but I don't even know what to Google to find this. Help!

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  • How to determine if CNF formula is satisfiable in Scheme?

    - by JJBIRAN
    Program a SCHEME function sat that takes one argument, a CNF formula represented as above. If we had evaluated (define cnf '((a (not b) c) (a (not b) (not d)) (b d))) then evaluating (sat cnf) would return #t, whereas (sat '((a) (not a))) would return (). You should have following two functions to work: (define comp (lambda (lit) ; This function takes a literal as argument and returns the complement literal as the returning value. Examples: (comp 'a) = (not a), and (comp '(not b)) = b. (define consistent (lambda (lit path) This function takes a literal and a list of literals as arguments, and returns #t whenever the complement of the first argument is not a member of the list represented by the 2nd argument; () otherwise. . Now for the sat function. The real searching involves the list of clauses (the CNF formula) and the path that has currently been developed. The sat function should merely invoke the real "workhorse" function, which will have 2 arguments, the current path and the clause list. In the initial call, the current path is of course empty. Hints on sat. (Ignore these at your own risk!) (define sat (lambda (clauselist) ; invoke satpath (define satpath (lambda (path clauselist) ; just returns #t or () ; base cases: ; if we're out of clauses, what then? ; if there are no literals to choose in the 1st clause, what then? ; ; then in general: ; if the 1st literal in the 1st clause is consistent with the ; current path, and if << returns #t, ; then return #t. ; ; if the 1st literal didn't work, then search << ; the CNF formula in which the 1st clause doesn't have that literal Don't make this too hard. My program is a few functions averaging about 2-8 lines each. SCHEME is consise and elegant! The following expressions may help you to test your programs. All but cnf4 are satisfiable. By including them along with your function definitions, the functions themselves are automatically tested and results displayed when the file is loaded. (define cnf1 '((a b c) (c d) (e)) ) (define cnf2 '((a c) (c))) (define cnf3 '((d e) (a))) (define cnf4 '( (a b) (a (not b)) ((not a) b) ((not a) (not b)) ) ) (define cnf5 '((d a) (d b c) ((not a) (not d)) (e (not d)) ((not b)) ((not d) (not e)))) (define cnf6 '((d a) (d b c) ((not a) (not d) (not c)) (e (not c)) ((not b)) ((not d) (not e)))) (write-string "(sat cnf1) ") (write (sat cnf1)) (newline) (write-string "(sat cnf2) ") (write (sat cnf2)) (newline) (write-string "(sat cnf3) ") (write (sat cnf3)) (newline) (write-string "(sat cnf4) ") (write (sat cnf4)) (newline) (write-string "(sat cnf5) ") (write (sat cnf5)) (newline)

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