Search Results

Search found 3838 results on 154 pages for 'throws'.

Page 128/154 | < Previous Page | 124 125 126 127 128 129 130 131 132 133 134 135  | Next Page >

  • Hot to set class variable to be visible to its public static methods?

    - by RCola
    Why I can noy access my variable p in mull form iterate method? How to resolve a problem? Hot to set class variable to be visible to its public static methods? public class mull { public static void main(String[] args) throws InterruptedException { final JPanel p = createAndShowGUI(); Timer timer = new Timer(1000, new MyTimerActionListener()); timer.start(); try { Thread.sleep(10000); } catch (InterruptedException e) { } timer.stop(); public static void iterate(){ for (int i = 0; i < 55; i++){ // "p cannot be resolved" p.moveSquare(i*10, i*10); p.setParamsRing(i*5, i*7, 200, 200); // p.repaint(); } } } class MyPanel extends JPanel { .... } How to access variable set in another method (in this example main())? Why Eclipse forces me to use this ((MyPanel) p).setParamsRing(i*5, i*7, 200, 200); instead of this p.setParamsRing(i*5, i*7, 200, 200);?

    Read the article

  • Need help: input int from console and pass it into method in different class and do math

    - by christophe
    i'm a beginner, Need help, Please!!! I want to read optional number "a" from console and then store it in variable to use as passing to a different class (different .java file). and pint the sum separetely by optional inputting. How do i code the 2 classes? thanks /* * DemoApp.java */ public class DemoApp { public static void main(String[] args) { Scanner input = new Scanner(System.in); int a; System.out.println("Input one of the following 3 numbers: 100, 200, 300"); System.out.print("Enter: "); a = input.nextInt(); TestApplication testapp = new TestApplication(); testapp.test(a); } } /* * TestApplication.java * */ public class TestApplication { private int a; public void test(int a) { this.a = a; // TODO: where to get the "a"? (entered by users from console) System.out.println("The number_a was passed in: "+a); } protected void printNum() throws Exception { int num; switch (a) { case 100: num = num + 10; break; case 200: num = num + 20; break; case 300: num = num + 30; break; default: // TODO: unexpected number input. throw(); break; } System.out.println("I got a sum number"+num); } }

    Read the article

  • Retrieving Relationships from within two arrays of pointers

    - by DanF
    In a portion of a program I'm working on, I need to count all the times each person has worked on projects with each other person. Let's say we have "Employee" entities and "Session" entities. In each session, there are four project types, "A", "B", "C", & "D", each a many-to-many relationship to Employees. I'm making a loop to systematically review every person a selected person has worked with. First, I put all their project types in a single array, so it's easier to loop through, but by the time I ask the last nested Project for its Employee members, I get an "unrecognized selector" error. IBOutlet NSArrayController * list; int x; for(x = 0; x < [list count]; x++){ NSArray *A = [[list objectAtIndex:x] valueForKey:@"projectAs"]; NSArray *A = [[list objectAtIndex:x] valueForKey:@"projectBs"]; NSArray *A = [[list objectAtIndex:x] valueForKey:@"projectCs"]; NSArray *A = [[list objectAtIndex:x] valueForKey:@"projectDs"]; NSArray *masterList = [[NSArray alloc] initWithObjects: projectAs, projectBs, projectCs, projectDs, nil]; int y; for(y = 0; y < [masterList count]; y++){ int z; for(z = 0; z < [[masterlist objectAtIndex:y] count]; z++){ //And now to make an Array of this employee's partners on the selected object, to run comparisons on. //I also have an array of keys for each session's teams, so that's what I'm referencing here: NSArray * thisTeam = [list objectAtIndex:y] objectAtIndex:z] valueForKey:projectKey]; This throws an exception... namely, -[_NSFaultingMutableSet objectAtIndex:]: unrecognized selector sent to instance What's wrong with that last Array creation?

    Read the article

  • Access to and availability of private member functions in C++

    - by David
    I am wandering the desert of my brain. I'm trying to write something like the following: class MyClass { // Peripherally Related Stuff public: void TakeAnAction(int oneThing, int anotherThing) { switch(oneThing){ case THING_A: TakeThisActionWith(anotherThing); break; //cases THINGS_NOT_A: }; }; private: void TakeThisActionWith(int thing) { string outcome = new string; outcome = LookUpOutcome(thing); // Do some stuff based on outcome return; } string LookUpOutcome(int key) { string oc = new string; oc = MyPrivateMap[key]; return oc; } map<int, string> MyPrivateMap; Then in the .cc file where I am actually using these things, while compiling the TakeAnAction section, it [CC, the solaris compiler] throws an an error: 'The function LookUpOutcome must have a prototype' and bombs out. In my header file, I have declared 'string LookUpOutcome(int key);' in the private section of the class. I have tried all sorts of variations. I tried to use 'this' for a little while, and it gave me 'Can only use this in non-static member function.' Sadly, I haven't declared anything static and these are all, putatively, member functions. I tried it [on TakeAnAction and LookUp] when I got the error, but I got something like, 'Can't access MyPrivateMap from LookUp'. MyPrivateMap could be made public and I could refer to it directly, I guess, but my sensibility says that is not the right way to go about this [that means that namespace scoped helper functions are out, I think]. I also guess I could just inline the lookup and subsequent other stuff, but my line-o-meter goes on tilt. I'm trying desperately not to kludge it.

    Read the article

  • Test a database conection without codeigniter throwing a fit, can it be done?

    - by RobertWHurst
    I'm just about finished my first release of automailer, a program I've been working on for a while now. I've just got to finish writing the installer. Its job is to rewrite the codigniter configs from templates. I've got the read/write stuff working, but I'd like to be able to test the server credentials given by the user without codingiter throwing a system error if they're wrong. Is there a function other than mysql_connect that I can use to test a connection that will return true or false and won't make codeigniter have a fit? This is what I have function _test_connection(){ if(mysql_connect($_POST['host'], $_POST['username'], $_POST['password'], TRUE)) return TRUE; else return FALSE; } Codigniter doesn't like this and throws a system error. <div style="border:1px solid #990000;padding-left:20px;margin:0 0 10px 0;"> <h4>A PHP Error was encountered</h4> <p>Severity: Warning</p> <p>Message: mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Unknown MySQL server host 'x' (1)</p> <p>Filename: controllers/install.php</p> <p>Line Number: 57</p> </div> I'd rather not turn off error reporting.

    Read the article

  • displaying a physical webpage with frames in iframe

    - by ksa
    i have iframe in my webpage, i have done the coding part for browsing the folders and viewing files in iframe.each folder has a index.html.now i need to display the index.html in iframe.index.html page contains frames divided into 2,each from different sources.i tried to display a sample webpage without frames and it was a success,page with frames spoils the party. my code for getting the html file <% String path=request.getParameter("name"); File directory = new File(path); FileFilter fileFilter=new FileFilter() { @Override public boolean accept(File file) { return file.getName().endsWith("html"); } }; File[] files = directory.listFiles(fileFilter); for (int index = 0; index < files.length; index++) { String s= files[index].getName(); String s1=files[index].getAbsolutePath(); %> <a href="fileview?name=<%=s1%>" target="sss"><%=s%></a> <% } %> mycode for displaying the page in iframe. public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException,IOException { res.setContentType("text/html"); PrintWriter out=res.getWriter(); String name=req.getParameter("name"); res.setHeader("Content-Disposition", "inline; filename=\""+name+"\""); java.io.FileInputStream fis=new java.io.FileInputStream(name); int i; while((i=fis.read())!=-1) { out.write(i); } fis.close(); out.close(); }

    Read the article

  • How to use the values from session variables in jsp pages that got saved using @Scope("session") in the mvc controllers

    - by droidsites
    Doing a web site using spring mvc. I added a SignupController to handle all the sign up related requests. Once user signup I am adding that to a session using @Scope("session"). Below is the SignupController code, SignupController.java @Controller @Scope("session") public class SignupController { @Autowired SignupServiceInter signUpService; private static final Logger logger = Logger.getLogger(SignupController.class); private String sessionUser; @RequestMapping("/SignupService") public ModelAndView signUp(@RequestParam("userid") String userId, @RequestParam("password") String password,@RequestParam("mailid") String emailId){ logger.debug(" userId:"+userId+"::Password::"+password+"::"); String signupResult; try { signUpService.registerUser(userId, password,emailId); sessionUser = userId; //adding the sign up user to the session return new ModelAndView("userHomePage","loginResult","Success"); //Navigate to user Home page if everything goes right } catch (UserExistsException e) { signupResult = e.toString(); return new ModelAndView("signUp","loginResult", signupResult); //Navigate to signUp page back if user does not exist } } } I am using "sessionUser" variable to store the signed up User Id. My understanding is that when I use @Scope("session") for the controller all the instance variables will added to HttpSession. So by that understanding I tried to access this "SessionUser" in userHomePage.jsp as, userHomepage.jsp Welcome to <%=session.getAttribute("sessionUser")%> But it throws null. So my question is how to use the values from session variables in jsp pages that got saved using @Scope("session") in the mvc controllers. Note: My work around is that pass that signed User Id to jsp page through ModelAndView, but it seems passing the value like these among the pages takes me back to managing state among pages using QueryStrings days.

    Read the article

  • How do I make this Java code operate properly? [Multi-threaded, race condition]

    - by Fixee
    I got this code from a student, and it does not work properly because of a race condition involving x++ and x--. He added synchronized to the run() method trying to get rid of this bug, but obviously this only excludes threads from entering run() on the same object (which was never a problem in the first place) but doesn't prevent independent objects from updating the same static variable x at the same time. public class DataRace implements Runnable { static volatile int x; public synchronized void run() { for (int i = 0; i < 10000; i++) { x++; x--; } } public static void main(String[] args) throws Exception { Thread [] threads = new Thread[100]; for (int i = 0; i < threads.length; i++) threads[i] = new Thread(new DataRace()); for (int i = 0; i < threads.length; i++) threads[i].start(); for (int i = 0; i < threads.length; i++) threads[i].join(); System.out.println(x); // x not always 0! } } Since we cannot synchronize on x (because it is primitive), the best solution I can think of is to create a new static object like static String lock = ""; and enclose the x++ and x-- within a synchronized block, locking on lock. But this seems really awkward. Is there a better way?

    Read the article

  • How to get a specific attribute from an object list?

    - by anarhikos
    I've an array keeping a list of Group objects. I want to set this list to the DropDownChoice component. However I want to show the end user only the name attribute of Group objects, and then get the selected values' id attribute to add database. What to do? private List<Group> groupTypes; DatabaseApp db = new DatabaseApp(); groupTypes = db.getGroups(); groupDropDownChoice = new DropDownChoice("type", groupTypes); ... ... addUserForm.add(new Button("submit"){ @Override public void onSubmit(){ Group group = (Group) groupDropDownChoice.getModelObject(); ... ... db.addUser(group.getId(), den, name, login, email, password1); DatabaseApp.java public List<Group> getGroups() throws SQLException{ List<Group> groups = new ArrayList<Group>(); try { String query = "SELECT * FROM [GROUP]"; Statement statement = db.createStatement(); ResultSet result = statement.executeQuery(query); while(result.next()){ int id = result.getInt("ID"); String name = result.getString("NAME"); groups.add(new Group(id, name)); } result.close(); } catch (SQLException ex) { throw new SQLException(ex.getMessage()); } return groups; }

    Read the article

  • Java: GatheringByteChannel advantages?

    - by Jason S
    I'm wondering when the GatheringByteChannel's write methods (taking in an array of ByteBuffers) have advantages over the "regular" WritableByteChannel write methods. I tried a test where I could use the regular vs. the gathering write method on a FileChannel, with approx 400KB/sec total in ByteBuffers of between 23-27 bytes in length in both cases. Gathering writes used an array of 64. The regular method used up approx 12% of my CPU, and the gathering method used up approx 16% of my CPU (worse than the regular method!) This tells me it's NOT useful to use gathering writes on a FileChannel around this range of operating parameters. Why would this be the case, and when would you ever use GatheringByteChannel? (on network I/O?) Relevant differences here: public void log(Queue<Packet> packets) throws IOException { if (this.gather) { int Nbuf = 64; ByteBuffer[] bbufs = new ByteBuffer[Nbuf]; int i = 0; Packet p; while ((p = packets.poll()) != null) { bbufs[i++] = p.getBuffer(); if (i == Nbuf) { this.fc.write(bbufs); i = 0; } } if (i > 0) { this.fc.write(bbufs, 0, i); } } else { Packet p; while ((p = packets.poll()) != null) { this.fc.write(p.getBuffer()); } } }

    Read the article

  • my div tag is not aligning properly after jquery.html replacement

    - by Adam
    <div class="container"><span class="field_label">Job</span><input class="fields2" type="text" maxlength="200" name="first_name" /></div> <div class="container"><span class="field_label">Date</span><input class="fields2" type="text" maxlength="200" name="the_date" id="the_date" /></div> <div class="container" id="sched_text">sdfdsfdsf</div> <!-- schedule text--> <div class="container"><span class="field_label">Time</span> .container{ position:relative; display:block; float:right; border: 1px solid; padding-bottom: 10px; } my html/css here has my containers aligning right below each other. However, when I use .html in jquery to change or add text to sched_text it throws the css off and places the div tag not as a block anymore but placed somewhere to the side. Does something change when you use .html text? what would the proper way of doing it? Thanks Ok the issue is that my .html or .text is not a string. I just did .text(the_Week[i][1]); which results in a number. How do I present it as a string?

    Read the article

  • Understanding Basic Prototyping & Updating Key/Value pairs

    - by JordanD
    First time poster, long time lurker. I'm trying to learn some more advanced features of .js, and have two ojectives based on the pasted code below: I would like to add methods to a parent class in a specific way (by invoking prototype). I intend to update the declared key/value pairs each time I make an associated method call. execMTAction as seen in TheSuper will execute each function call, regardless. This is by design. Here is the code: function TheSuper(){ this.options = {componentType: "UITabBar", componentName: "Visual Browser", componentMethod: "select", componentValue: null}; execMTAction(this.options.componentType, this.options.componentName, this.options.componentMethod, this.options.componentValue); }; TheSuper.prototype.tapUITextView = function(val1, val2){ this.options = {componentType: "UITextView", componentName: val1, componentMethod: "entertext", componentValue: val2}; }; I would like to execute something like this (very simple): theSuper.executeMTAction(); theSuper.tapUITextView("a", "b"); Unfortunately I am unable to overwrite the "this.options" in the parent, and the .tapUITextView method throws an error saying it cannot find executeMTAction. All I want to do, like I said, is to update the parameters in the parent, then have executeMTAction run each time I make any method call. That's it. Any thoughts? I understand this is basic but I'm coming from a long-time procedural career and .js seems to have this weird confluence of oo/procedural that I'm having a bit of difficulty with. Thanks for any input!

    Read the article

  • Retrieving an element by array index in jQuery vs the each() function.

    - by Alex Ciminian
    I was writing a "pluginable" function when I noticed the following behavior (tested in FF 3.5.9 with Firebug 1.5.3). $.fn.computerMove = function () { var board = $(this); var emptySquares = board.find('div.clickable'); var randPosition = Math.floor(Math.random() * emptySquares.length); emptySquares.each(function (index) { if (index === randPosition) { // logs a jQuery object console.log($(this)); } }); target = emptySquares[randPosition]; // logs a non-jQuery object console.log(target); // throws error: attr() not a function for target board.placeMark({'position' : target.attr('id')}); } I noticed the problem when the script threw an error at target.attr('id') (attr not a function). When I checked the log, I noticed that the output (in Firebug) for target was: <div style="width: 97px; height: 97px;" class="square clickable" id="8"></div> If I output $(target), or $(this) from the each() function, I get a nice jQuery object: [ div#8.square ] Now here comes my question: why does this happen, considering that find() seems to return an array of jQuery objects? Why do I have to do $() to target all over again? [div#0.square, div#1.square, div#2.square, div#3.square, div#4.square, div#5.square, div#6.square, div#7.square, div#8.square] Just a curiosity :).

    Read the article

  • Help with java threads or executors: Executing several MySQL selects, inserts and updates simmultane

    - by Martin
    Hi. I'm writing an application to analyse a MySQL database, and I need to execute several DMLs simmultaneously; for example: // In ResultSet rsA: Select * from A; rsA.beforeFirst(); while (rsA.next()) { id = rsA.getInt("id"); // Retrieve data from table B: Select * from B where B.Id=" + id; // Crunch some numbers using the data from B // Close resultset B } I'm declaring an array of data objects, each with its own Connection to the database, which in turn calls several methods for the data analysis. The problem is all threads use the same connection, thus all tasks throw exceptios: "Lock wait timeout exceeded; try restarting transaction" I believe there is a way to write the code in such a way that any given object has its own connection and executes the required tasks independent from any other object. For example: DataObject dataObject[0] = new DataObject(id[0]); DataObject dataObject[1] = new DataObject(id[1]); DataObject dataObject[2] = new DataObject(id[2]); ... DataObject dataObject[N] = new DataObject(id[N]); // The 'DataObject' class has its own connection to the database, // so each instance of the object should use its own connection. // It also has a "run" method, which contains all the tasks required. Executor ex = Executors.newFixedThreadPool(10); for(i=0;i<=N;i++) { ex.execute(dataObject[i]); } // Here where the problem is: Each instance creates a new connection, // but every DML from any of the objects is cluttered in just one connection // (in MySQL command line, "SHOW PROCESSLIST;" throws every connection, and all but // one are idle). Can you point me in the right direction? Thanks

    Read the article

  • Cannot understand the behaviour of C# compiler while instantiating a class thru interface

    - by Newbie
    I have a class that implements an interface. The interface is public interface IRiskFactory { void StartService(); void StopService(); } The class that implements the interface is public class RiskFactoryService : IRiskFactory { } Now I have a console application and one window service. From the console application if I write the following code static void Main(string[] args) { IRiskFactory objIRiskFactory = new RiskFactoryService(); objIRiskFactory.StartService(); Console.ReadLine(); objIRiskFactory.StopService(); } It is working fine. However, when I mwrite the same piece of code in Window service public partial class RiskFactoryService : ServiceBase { IRiskFactory objIRiskFactory = null; public RiskFactoryService() { InitializeComponent(); objIRiskFactory = new RiskFactoryService(); <- ERROR } /// <summary> /// Starts the service /// </summary> /// <param name="args"></param> protected override void OnStart(string[] args) { objIRiskFactory.StartService(); } /// <summary> /// Stops the service /// </summary> protected override void OnStop() { objIRiskFactory.StopService(); } } It throws error: Cannot implicitly convert type 'RiskFactoryService' to 'IRiskFactory'. An explicit conversion exists (are you missing a cast?) When I type cast to the interface type, it started working objIRiskFactory = (IRiskFactory)new RiskFactoryService(); My question is why so?

    Read the article

  • Java to JavaScript (Encryptation related)

    - by balexandre
    Hi guys, I'm having dificulties to get the same string in Javascript and I'm thinking that I'm doing something wrong... Java code: import java.io.UnsupportedEncodingException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.util.Date; import java.util.GregorianCalendar; import sun.misc.BASE64Encoder; private static String getBase64Code(String input) throws UnsupportedEncodingException, NoSuchAlgorithmException { String base64 = ""; byte[] txt = input.getBytes("UTF8"); byte[] text = new byte[txt.length+3]; text[0] = (byte)239; text[1] = (byte)187; text[2] = (byte)191; for(int i=0; i<txt.length; i++) text[i+3] = txt[i]; MessageDigest md = MessageDigest.getInstance("MD5"); md.update(text); byte digest[] = md.digest(); BASE64Encoder encoder = new BASE64Encoder(); base64 = encoder.encode(digest); return base64; } I'm trying this using Paj's MD5 script as well Farhadi Base 64 Encode script but my tests fail completly :( my code: function CalculateCredentialsSecret(type, user, pwd) { var days = days_between(new Date(), new Date(2000, 1, 1)); var str = type.toUpperCase() + user.toUpperCase() + pwd.toUpperCase() + days; var md5 = any_md5('', str); var b64 = base64Encode(md5); return encodeURIComponent(b64); } Does anyone know how can I convert this Java method into a Javascript one? Thank you

    Read the article

  • java regex for alpha and spaces is including [ ] \

    - by JayAvon
    This is my regex for my JTextField to not be longer than x characters and to not include anything other than letters or spaces. For some reason it is allowing [ ] and \ characters. This is driving me crazy. Is my regex wrong?? package com.jayavon.game.helper; import java.awt.Toolkit; import javax.swing.text.AttributeSet; import javax.swing.text.BadLocationException; import javax.swing.text.PlainDocument; public class CharacterNameCreationDocument extends PlainDocument { private static final long serialVersionUID = 1L; private int limit; public CharacterNameCreationDocument(int limit) { super(); this.limit = limit; } public void insertString(int offset, String str, AttributeSet attr) throws BadLocationException { if (str == null || (getLength() + str.length()) > limit || !str.matches("[a-zA-z\\s]*")){ Toolkit.getDefaultToolkit().beep(); return; } else { super.insertString(offset, str, attr); } } }

    Read the article

  • public String shorthand(String in)

    - by luvthug
    Hi All, I am stuck on this code. The code should use the class StringBuilder to build an output string by appending non-vowel characters from its argument in to the result it returns. It needs to identify vowels to be removed using the helper metod i created which is public boolean isVowel(char c). public String shorthand(String in) this is the method I need help with. I have created the stringbuilder but the if condition does not accept isVowel method. import java.io.*; import java.util.*; public class Shorthand { public boolean isVowel(char c) { if (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u' || c == 'A'|| c == 'E'||c == 'I'|| c == 'O'|| c == 'U') { return true; } else { return false; } } //TODO Complete the shorthand method public String shorthand(String in) //this is the code I need help with { StringBuilder vowel = new StringBuilder(); if (isVowel() == false)strong text { vowel.append(in); } return vowel.toString(); } //TODO Complete the run method public void run() throws IOException { String yourLine; Scanner sc = new Scanner(System.in); yourLine = sc.nextLine(); while(!yourLine.equals("*")); { System.out.println("Enter your line of text"); } yourLine = sc.nextLine(); } }

    Read the article

  • ArrayIndexOutOfBoundsException double array size

    - by Andy
    I'm going to preface this question with this statement: I know that I can easily handle this problem by reading the amount of lines in a file and making an array that size. I am not allowed to do this. Anyway, here is my question. I need to double my array's size whenever my program encounters an ArrayIndexOutOfBoundsException and then copy all the previous read in information into the larger array. Here is my code public static void main(String[] args) throws IOException { Scanner inScan, fScan = null; int [] A = new int[5]; inScan = new Scanner(System.in); System.out.print("Please enter the file to read from: "); while(true) { try{ String fName = inScan.nextLine(); fScan = new Scanner(new File(fName)); break; } catch (FileNotFoundException ex) { System.out.println("Your file is invalid -- please re-enter"); } } String nextItem; int nextInt = 0; int i = 0; while (fScan.hasNextLine()) { try { nextItem = fScan.nextLine(); nextInt = Integer.parseInt(nextItem); A[i] = nextInt; i++; } catch (NumberFormatException e) { System.out.println("Found an invalid int -- ignored"); } catch (ArrayIndexOutOfBoundsException e) { //double the size of array A until //copy all previous read in information to the larger array } } System.out.println("Here are your " + i + " items:"); for (int j = 0; j < i; j++) { System.out.println(A[j] + " "); } } }

    Read the article

  • Identify words with ascending characters from text file

    - by user2914000
    I am having a fair amount of trouble trying to write a program that counts the amount of ascending words (words in which each character is larger than the previous character) in a text file. I have tried a few different methods to solve this but cannot seem to get it working. If anyone could help me revise the code to work properly it would be appreciated. The code will print about 5 of the words from the list of nearly 20000, but none considered are ascending (the file does have many ascending words) and it sometimes prints the same word twice. I am printing theWord to the console simply to see if the code works. import java.util.Scanner; import java.io.*; public class { public static void main (String [] args) throws FileNotFoundException{ String theWord; Scanner inputFile = new Scanner(new File("file.txt")); boolean ascending = true; int i = 1; while(inputFile.hasNextLine()){ theWord = inputFile.nextLine(); if(theWord.length() >= 2){ while(i < theWord.length() - 1){ if(theWord.charAt(i) <= theWord.charAt(i + 1)){ ascending = true; System.out.println("+ " + theWord); totalNum = totalNum + 1; } else{ ascending = false; System.out.println("= " + theWord); } i++; } } }

    Read the article

  • Another C++ question, delete not working?

    - by kyeana
    New to c++, and am having a problem with delete and destructor (I am sure i am making a stupid mistake here, but haven't been able to figure it out as of yet). When i step through into the destructor, and attepmt to call delete on a pointer, the message shows up "Cannot access memory at address some address." The relevant code is: /* * Removes the front item of the linked list and returns the value stored * in that node. * * TODO - Throws an exception if the list is empty */ std::string LinkedList::RemoveFront() { LinkedListNode *n = pHead->GetNext(); // the node we are removing std::string rtnData = n->GetData(); // the data to return // un-hook the node from the linked list pHead->SetNext(n->GetNext()); n->GetNext()->SetPrev(pHead); // delete the node delete n; n=0; size--; return rtnData; } and /* * Destructor for a linked node. * * Deletes all the dynamically allocated memory, and sets those pointers to 0. */ LinkedListNode::~LinkedListNode() { delete pNext; // This is where the error pops up delete pPrev; pNext=0; pPrev=0; }

    Read the article

  • Dont understand the concept of extends in URL.openConnection() in JAVA

    - by user1722361
    Hi I am trying to learn JAVA deeply and so I am digging into the JDK source code in the following lines: URL url = new URL("http://www.google.com"); URLConnection tmpConn = url.openConnection(); I attached the source code and set the breakpoint at the second line and stepped into the code. I can see the code flow is: URL.openConnection() - sun.net.www.protocol.http.Handler.openConnection() I have two questions about this First In URL.openConnection() the code is: public URLConnection openConnection() throws java.io.IOException { return handler.openConnection(this); } handler is an object of URLStreamHandler, define as blow transient URLStreamHandler handler; But URLStreamHandler is a abstract class and method openConnection() is not implement in it so when handler calls this method, it should go to find a subclass who implement this method, right? But there are a lot classes who implement this methods in sun.net.www.protocol (like http.Hanlder, ftp.Handler ) How should the code know which "openConnection" method it should call? In this example, this handler.openConnection() will go into http.Handler and it is correct. (if I set the url as ftp://www.google.com, it will go into ftp.Handler) I cannot understand the mechanism. second. I have attached the source code so I can step into the JDK and see the variables but for many classes like sun.net.www.protocol.http.Handler, there are not source code in src.zip. I googled this class and there is source code online I can get but why they did not put it (and many other classes) in the src.zip? Where can I find a comprehensive version of source code? Thanks!

    Read the article

  • how get attribute relation from another entity class Java Persistance API and show to JSP through servlet?

    - by user1787209
    I have 2 entities are entities meeting and meetingAgenda. I write code entity class (EJB) from database like this. public class Meeting implements Serializable { ...... @XmlTransient public Collection<MeetingAgenda> getMeetingAgendaCollection() { return meetingAgendaCollection; } public void setMeetingAgendaCollection(Collection<MeetingAgenda> meetingAgendaCollection) { this.meetingAgendaCollection = meetingAgendaCollection; } ....... } and entity class meeting agenda like this. ..... public class MeetingAgenda implements Serializable { .... public String getAgenda() { return agenda; } public void setAgenda(String agenda) { this.agenda = agenda; } .... } method getMeetingAgendaCollection is a relation from meeting entity . then, in my controller servlet i call EJB like this. public class ControllerServlet extends HttpServlet { @EJB private RapatFacadeLocal rapatFacade; public void init() throws ServletException { // store category list in servlet context getServletContext().setAttribute("meetings", rapatFacade.findAll()); } ...... i want to show data from table entities meeting and meetingAgenda...but i can't.. please help.. i write code in JSP page.. like this.. <c:forEach var="meeting" items="${meetings}"> <td> MeetingCode : ${meeting.meetingCode} </td> <td> Meeting : ${meeting.meeting} </td> <td> Agenda : ${meeting.getMeetingAgendaCollection} </td> </c:forEach> how do I display data Agenda using getMeetingAgendaCollection ???? thanks for your help.

    Read the article

  • gmail app 504 server timeout

    - by Hui
    this is the part of code I use for getting info from gmail, it's working alright on my localhost, but somehow when i deploy it online, I got 504 gateway timeout error. Did I missed something in my code? can someone give some advices , thanks a lot public class GetGmail { static String last = null; public static ArrayList run(String username, String password, String lastloggin)throws Exception { ArrayList result = null; System.out.println("Getting Gmail......"); last = lastloggin; Properties props = System.getProperties(); props.setProperty("mail.store.protocol", "imaps"); try { Session session = Session.getDefaultInstance(props, null); Store store = session.getStore("imaps"); store.connect("imap.googlemail.com", username, password); result = readMessage(store); store.close(); } catch (NoSuchProviderException e) { e.printStackTrace(); return null; } catch (MessagingException e) { e.printStackTrace(); return null; } return result; } }

    Read the article

  • Java getMethod with subclass parameter

    - by SelectricSimian
    I'm writing a library that uses reflection to find and call methods dynamically. Given just an object, a method name, and a parameter list, I need to call the given method as though the method call were explicitly written in the code. I've been using the following approach, which works in most cases: static void callMethod(Object receiver, String methodName, Object[] params) { Class<?>[] paramTypes = new Class<?>[params.length]; for (int i = 0; i < param.length; i++) { paramTypes[i] = params[i].getClass(); } receiver.getClass().getMethod(methodName, paramTypes).invoke(receiver, params); } However, when one of the parameters is a subclass of one of the supported types for the method, the reflection API throws a NoSuchMethodException. For example, if the receiver's class has testMethod(Foo) defined, the following fails: receiver.getClass().getMethod("testMethod", FooSubclass.class).invoke(receiver, new FooSubclass()); even though this works: receiver.testMethod(new FooSubclass()); How do I resolve this? If the method call is hard-coded there's no issue - the compiler just uses the overloading algorithm to pick the best applicable method to use. It doesn't work with reflection, though, which is what I need. Thanks in advance!

    Read the article

< Previous Page | 124 125 126 127 128 129 130 131 132 133 134 135  | Next Page >