Search Results

Search found 36013 results on 1441 pages for 'public fields'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 307/1441 | < Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >

  • Eclipse Plugin: Enablement of an Action based on the current selection

    - by Itay
    I am using the org.eclipse.ui.popupMenus extension point for adding a sub-menu whose Action that is bounded to the following class: public class MyAction implements IObjectActionDelegate { private Logic logic = Logic.getInstance(); // Singleton public void setActivePart(IAction a, IWorkbenchPart targetPart) { // Nothing here } public void run(IAction a) { // Do something... } public void selectionChanged(IAction a, ISelection s) { a.setEnabled(logic.isEnabled(s)); } } This action is working correctly in most cases (including the call a.setEnabled() in selectionChanged()). My problem at the very first time my action is being invoked. The selectionChanged method is called only after the menu item has been displayed (and not when the user has made the selection) which means that the call to a.setEnabled() will have no affect. Any ideas on how to make my action receive selectionChanged() notifications even before the fist time it is being invoked?

    Read the article

  • this is my first time asking here, I wanted to create a linked list while sorting it thanks

    - by user2738718
    package practise; public class Node { // node contains data and next public int data; public Node next; //constructor public Node (int data, Node next){ this.data = data; this.next = next; } //list insert method public void insert(Node list, int s){ //case 1 if only one element in the list if(list.next == null && list.data > s) { Node T = new Node(s,list); } else if(list.next == null && list.data < s) { Node T = new Node(s,null); list.next = T; } //case 2 if more than 1 element in the list // 3 elements present I set prev to null and curr to list then performed while loop if(list.next.next != null) { Node curr = list; Node prev = null; while(curr != null) { prev = curr; curr = curr.next; if(curr.data > s && prev.data < s){ Node T = new Node(s,curr); prev.next = T; } } // case 3 at the end checks for the data if(prev.data < s){ Node T = new Node(s,null); prev.next = T; } } } } // this is a hw problem, i created the insert method so i can check and place it in the correct order so my list is sorted This is how far I got, please correct me if I am wrong, I keep inserting node in the main method, Node root = new Node(); and root.insert() to add.

    Read the article

  • C# to Java Conversion: What is a [DefaultProperty("value")]?

    - by Shiftbit
    I do not understand how the DefaultProperty Metadata tag work or what it signifies. I've read the MSDN and went through the sample but I find it confusing. DefaultPropertyAttribute Class I've read a few blogs and they seem to refer to the indexers. I'm not sure why you would want metadata for your properties? I am coming from a Java background, perhaps a Java analogy would help. [DefaultProperty("Value")] public abstract class FOO<T> : ANY, IBAR<T> { public FOO() { } public FOO(T value) { this.Value = value; } public virtual T Value { get; set; } }

    Read the article

  • Java Array Index Out of Bounds Exception

    - by user1302023
    I need help debugging the following program: I'm getting a run time error that reads: Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 at SearchEngine.main(SearchEngine.java:126) import java.util.*; import java.io.*; public class SearchEngine { public static int getNumberOfWords (File f) throws FileNotFoundException { int numWords = 0; Scanner scan = new Scanner(f); while (scan.hasNext()) { numWords++; scan.next(); } scan.close(); return numWords; } public static void readInWords (File input, String [] x) throws FileNotFoundException { Scanner scan = new Scanner(input); int i = 0; while (scan.hasNext() && i<x.length) { x[i] = scan.next(); i++; } scan.close(); } public static int getNumOfDistinctWords (File input, String [] x) throws FileNotFoundException { Scanner scan = new Scanner(input); int count = 0; int i = 1; while (scan.hasNext() && i<x.length) { if (!x[i].equals(x[i-1])) { count++; } i++; } scan.close(); return count; } public static void readInDistinctWords (String [] x, String [] y) { int i = 1; int k = 0; while (i<x.length) { if (!x[i].equals(x[i-1])) { y[k] = x[i]; k++; } i++; } } public static int getNumberOfLines (File input) throws FileNotFoundException { int numLines = 0; Scanner scan = new Scanner(input); while (scan.hasNextLine()) { numLines++; scan.nextLine(); } scan.close(); return numLines; } public static void readInLines (File input, String [] x) throws FileNotFoundException { Scanner scan = new Scanner(input); int i = 0; while (scan.hasNextLine() && i<x.length) { x[i] = scan.nextLine(); i++; } scan.close(); } public static void main(String [] args) { try { //gets file name System.out.println("Enter the name of the text file you wish to search"); Scanner kb = new Scanner(System.in); String fileName = kb.nextLine(); String TXT = ".txt"; if (!fileName.endsWith(TXT)) { fileName = fileName.concat(TXT); } File input = new File(fileName); //First part of creating index System.out.println("Creating vocabArray"); int NUM_WORDS = getNumberOfWords(input); //System.out.println(NUM_WORDS); String [] wordArray = new String[NUM_WORDS]; readInWords(input, wordArray); Arrays.sort(wordArray); int NUM_DISTINCT_WORDS = getNumOfDistinctWords(input, wordArray); String [] vocabArray = new String[NUM_DISTINCT_WORDS]; readInDistinctWords(wordArray, vocabArray); System.out.println("Finished creating vocabArray"); System.out.println("Creating concordanceArray"); int NUM_LINES = getNumberOfLines(input); String [] concordanceArray = new String[NUM_LINES]; readInLines(input, concordanceArray); System.out.println("Finished creating concordanceArray"); System.out.println("Creating invertedIndex"); int [][] invertedIndex = new int[NUM_DISTINCT_WORDS][10]; int [] wordCountArray = new int[NUM_DISTINCT_WORDS]; int lineNum = 0; while (lineNum<concordanceArray.length) { Scanner scan = new Scanner(concordanceArray[lineNum]); while (scan.hasNext()) { int wordPos = Arrays.binarySearch(vocabArray, scan.next()); wordCountArray[wordPos]+=1; for(int i = 0; i < invertedIndex.length; i++) { for(int j = 0; j < invertedIndex[i].length; j++) { if (invertedIndex[i][j] == 0) { invertedIndex[i][j] = lineNum; break; } } } } lineNum++; } System.out.println("Finished creating invertedIndex"); } catch (FileNotFoundException exception) { System.out.println("File Not Found"); } } //main } //class

    Read the article

  • Managed .NET Equivalent to CreateFile & WriteFile from WinBase (kernel32.dll)

    - by StevenH
    I am working with a legacy file format. The file is created using unmanaged C++ that utilizes the WinBase.h CreateFile() & WriteFile() functions (found in the kernel32.dll). I have been using P/Invoke interop to access these native functions like so: [DllImport("kernel32.dll")] public static extern bool WriteFile( IntPtr hFile, byte[] lpBuffer, uint nNumberOfBytesToWrite, out uint lpNumberOfBytesWritten, [In] ref NativeOverlapped lpOverlapped); [DllImport("kernel32.dll", SetLastError = true)] public static extern bool WriteFileEx( IntPtr hFile, byte[] lpBuffer, uint nNumberOfBytesToWrite, [In] ref NativeOverlapped lpOverlapped, WriteFileCompletionDelegate lpCompletionRoutine); [DllImport("kernel32.dll", SetLastError = true)] public static extern IntPtr CreateFile( string lpFileName, uint dwDesiredAccess, uint dwShareMode, IntPtr lpSecurityAttributes, uint dwCreationDisposition, uint dwFlagsAndAttributes, IntPtr hTemplateFile); [DllImport("kernel32.dll", SetLastError = true)] public static extern bool CloseHandle(IntPtr hObject); public delegate void WriteFileCompletionDelegate( UInt32 dwErrorCode, UInt32 dwNumberOfBytesTransfered, ref NativeOverlapped lpOverlapped); The issue with this is when I call WriteFile(), the file is always overwritten by the proceeding call. I need to find a compatible .NET equivalent that would allow me to produce the exact same format of output. Thanks.

    Read the article

  • NHibernate: discriminator without common base class?

    - by joniba
    Is it possible to map two classes to the same property without them sharing a common base class? For example, a situation like this: class Rule { public virtual int SequenceNumber { get; set; } public virtual ICondition Condition { get; set; } } interface ICondition { } class ExpressionCondition : ICondition { public virtual string Expression { get; set; } } class ThresholdCondition : ICondition { public virtual int Threshold { get; set; } } I also cannot add some empty abstract class that both conditions inherit from because the two ICondition implementations exist in different domains that are not allowed to reference each other. (Please no responses telling me that this situation should not occur in the first place - I'm aware of it and it doesn't help me.)

    Read the article

  • Iterator blocks and inheritance.

    - by Dave Van den Eynde
    Given a base class with the following interface: public class Base { public virtual IEnumerable<string> GetListOfStuff() { yield return "First"; yield return "Second"; yield return "Third"; } } I want to make a derived class that overrides the method, and adds its own stuff, like so: public class Derived : Base { public override IEnumerable<string> GetListOfStuff() { foreach (string s in base.GetListOfStuff()) { yield return s; } yield return "Fourth"; yield return "Fifth"; } } However, I'm greeted with a warning that "access to a member through a base keyword from an iterator cannot be verified". What's the accepted solution to this problem then?

    Read the article

  • Trying to write priority queue in Java but getting "Exception in thread "main" java.lang.ClassCastEx

    - by Dan
    For my data structure class, I am trying to write a program that simulates a car wash and I want to give fancy cars a higher priority than regular ones using a priority queue. The problem I am having has something to do with Java not being able to type cast "Object" as an "ArrayQueue" (a simple FIFO implementation). What am I doing wrong and how can I fix it? public class PriorityQueue<E> { private ArrayQueue<E>[] queues; private int highest=0; private int manyItems=0; public PriorityQueue(int h) { highest=h; queues = (ArrayQueue[]) new Object[highest+1]; <----problem is here } public void add(E item, int priority) { queues[priority].add(item); manyItems++; } public boolean isEmpty( ) { return (manyItems == 0); } public E remove() { E answer=null; int counter=0; do { if(!queues[highest-counter].isEmpty()) { answer = queues[highest-counter].remove(); counter=highest+1; } else counter++; }while(highest-counter>=0); return answer; } }

    Read the article

  • Rails caches_page :index in Wrong Location

    - by Andy
    I have a controller Projects in my Rails app with: caches_page :index However, instead of the cached file being generated at /public/projects/index.html it is located at /public/projects.html. The web server (currently Mongrel) looks for */ directories before *.html files. So the http://…/projects request is routed through Rails and my index cache file is never served. How can I tell caches_page :index to generate the file at /public/projects/index.html instead?

    Read the article

  • MySQL: selecting all but one field?

    - by gsquare567
    instead of SELECT * FROM mytable, i would like to select all fields EXCEPT one (namely, the 'serialized' field, which stores a serialized object). this is because i think that losing that field will speed up my query by a lot. however, i have so many fields and am quite the lazy guy. is there a way to say... `SELECT ALL_ROWS_EXCEPT(serialized) FROM mytable` ? thanks!

    Read the article

  • abstract class in C++

    - by Alexander
    I have a derived derived class from an abstract class. The code is below. I have a FishTank class which is derived from an Aquarium and Aquarium is derived from item. My question is that should I put the definition of virtual int minWidth() const = 0; in aquarium again or is the code below sufficient? class Item{ public: virtual int minWidth() const = 0; }; class Aquarium{ public: virtual int calWidth() = 0; // Pure virtual function. }; class FishTank : public Aquarium{ public: FishTank(int base1, int base2, int height); ~FishTank(); int calWidth(); int minWidth(); };

    Read the article

  • SQL for sorting boolean column as true, null, false

    - by petehern
    My table has three boolean fields: f1, f2, f3. If I do SELECT * FROM table ORDER BY f1, f2, f3 the records will be sorted by these fields in the order false, true, null. I wish to order them with null in between true and false: the correct order should be true, null, false. I am using PostgreSQL.

    Read the article

  • ActionScript Accessing Functions/Vars From Outside Of Class

    - by TheDarkIn1978
    how can i call public functions or vars of a sprite class from another class (or frame script)? i keep getting 1061: Call to a possibly undefined method (function i'm trying to call) through a reference with static type flash.display:Sprite. //Framescript var a:Sprite = new customRect(); addChild(a); a.getSide(); //.as file package { import flash.display.Sprite; public class customRect extends Sprite { public var side:Number; private function customRect() { var box:Sprite = new Sprite(); box.graphics.beginFill(); box.graphics.drawRect(0, 0, 200, 200); box.graphics.endFill(); side = box.width; } public function getSide():void { trace(side); } } }

    Read the article

  • xstream handles non-english character

    - by Yan Cheng CHEOK
    I have the following code : /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package helloworld; import com.thoughtworks.xstream.XStream; import java.io.File; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import javax.swing.JOptionPane; /** * * @author yccheok */ public class Test { @SuppressWarnings("unchecked") public static <A> A fromXML(Class c, File file) { XStream xStream = new XStream(); InputStream inputStream = null; try { inputStream = new java.io.FileInputStream(file); Object object = xStream.fromXML(inputStream); if (c.isInstance(object)) { return (A)object; } } catch (Exception exp) { exp.printStackTrace(); } finally { if (inputStream != null) { try { inputStream.close(); inputStream = null; } catch (java.io.IOException exp) { exp.printStackTrace(); return null; } } } return null; } @SuppressWarnings("unchecked") public static <A> A fromXML(Class c, String filePath) { return (A)fromXML(c, new File(filePath)); } public static boolean toXML(Object object, File file) { XStream xStream = new XStream(); OutputStream outputStream = null; try { outputStream = new FileOutputStream(file); xStream.toXML(object, outputStream); } catch (Exception exp) { exp.printStackTrace(); return false; } finally { if (outputStream != null) { try { outputStream.close(); outputStream = null; } catch (java.io.IOException exp) { exp.printStackTrace(); return false; } } } return true; } public static boolean toXML(Object object, String filePath) { return toXML(object, new File(filePath)); } public static void main(String args[]) { String s = "\u6210\u4EA4\u91CF"; // print ??? System.out.println(s); // fine! show ??? JOptionPane.showMessageDialog(null, s); toXML(s, "C:\\A.XML"); String o = fromXML(String.class, "C:\\A.XML"); // show ??? JOptionPane.showMessageDialog(null, o); } } I run the following code through command prompt in Windows Vista. 1) May I know why System.out.println unable to print out Chinese Character in console? 2) I open up the xstream file. The saved value is <string>???</string> How can I make xstream save Chinese Character correctly? Thanks.

    Read the article

  • Flickering when repainting a JPanel inside a JScrollPAne

    - by pR0Ps
    I'm having a problem with repainting a JPanel inside a JScrollPane. Basically, I'm just trying to 'wrap' my existing EditPanel (it originally extended JPanel) into a JScrollPane. It seems that the JPanel updates too often (mass flickering). How would I stop this from happening? I tried using the setIgnoreRepaint() but it didn't seem to do anything. Will this current implementation work or would I need to create another inner class to fine-tune the JPanel I'm using to display graphics? Skeleton code: public class MyProgram extends JFrame{ public MyProgram(){ super(); add(new EditPanel()); pack(); } private class EditPanel extends JScrollPane{ private JPanel graphicsPanel; public EditPanel(){ graphicsPanel = new JPanel(); } public void paintComponent(Graphics g){ graphicsPanel.revalidate(); //update the scrollpane to current panel size repaint(); Graphics g2 = graphicsPanel.getGraphics(); g2.drawImage(imageToDraw, 0, 0, null); } } }

    Read the article

  • GUI Freezes and Output to JTextField from user input

    - by user2929005
    I am having I hope only two issues currently. I have had help on this on a previous question that I have asked but now I am running into different issues. My current issues now is that I need to print out into a JTextField a sorted array. I do not have questions about how to sort the array I just would like help on how to get the array to print to the JTextField when the Bubble Sort button is pressed. Currently when I press the button it freezes. It freezes at this line. list.add(Integer.valueOf(input.nextInt())); please help Thank you. import java.awt.EventQueue; import javax.swing.*; import java.awt.event.*; import java.util.*; public class Sorting { private JFrame frame; private JTextArea inputArea; private JTextField outputArea; ArrayList<Integer> list = new ArrayList<Integer>(); Scanner input = new Scanner(System.in); /** * Launch the application. */ public static void main(String[] args) { EventQueue.invokeLater(new Runnable() { public void run() { try { Sorting window = new Sorting(); window.frame.setVisible(true); } catch (Exception e) { e.printStackTrace(); } } }); } /** * Create the application. */ public Sorting() { initialize(); } /** * Initialize the contents of the frame. */ private void initialize() { frame = new JFrame(); frame.setBounds(100, 100, 450, 300); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setTitle("Sorting"); frame.getContentPane().setLayout(null); JButton bubbleButton = new JButton("Bubble Sort"); bubbleButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent arg0) { list.add(Integer.valueOf(input.nextInt())); // for(int i = 0; i < list.size(); i++){ // // } } }); bubbleButton.setBounds(10, 211, 114, 23); frame.getContentPane().add(bubbleButton); JButton mergeButton = new JButton("Merge Sort"); mergeButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { } }); mergeButton.setBounds(305, 211, 114, 23); frame.getContentPane().add(mergeButton); JButton quickButton = new JButton("Quick Sort"); quickButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { } }); quickButton.setBounds(163, 211, 114, 23); frame.getContentPane().add(quickButton); inputArea = new JTextArea(); inputArea.setBounds(10, 36, 414, 51); frame.getContentPane().add(inputArea); outputArea = new JTextField(); outputArea.setEditable(false); outputArea.setBounds(10, 98, 414, 59); frame.getContentPane().add(outputArea); outputArea.setColumns(10); JLabel label = new JLabel("Please Enter 5 Numbers"); label.setHorizontalAlignment(SwingConstants.CENTER); label.setBounds(10, 11, 414, 14); frame.getContentPane().add(label); } }

    Read the article

  • abstract class need acces to subclass atribute

    - by user1742980
    I have a problem with my code. public abstract class SimplePolygon implements Polygon { ... public String toString(){ String str = "Polygon: vertices ="; for(int i = 0;i<varray.length;i++){ str += " "; str += varray[i]; } return str; } } public class ArrayPolygon extends SimplePolygon { private Vertex2D[] varray; public ArrayPolygon(Vertex2D[] array){ varray = new Vertex2D[array.length]; if (array == null){} for(int i = 0;i<array.length;i++){ if (array[i] == null){} varray[i] = array[i]; } ... } Problem is, that i'm not allowed to add any atribute or method to abstract class SimplePolygon, so i'cant properly initialize varray. It could simply be solved with protected atrib in that class, but for some (stupid) reason i'cant do that. Has anybody an idea how to solve it without that? Thanks for all help.

    Read the article

  • How do you select form elements in JQuery based upon an html table?

    - by Swoop
    I am working on some ASP.NET web forms which involves some dynamic generation, and I need to add some onClick helpers on the client side. I have a basic outline of something working, except for one huge problem. There are multiple HTML tables, each generated by a different ASP.NET web control. Each table can contain overlapping field names, which is causing a problem with my JQuery click event handlers. The click event handler is linking to unintended form fields in addition to the intended form field. I have provided a simplified sample version of the code below. This code is trying to set the value of textbox box1 when a particular radiobutton is selected in the table with id=thing1. Obviously, the jquery code will be triggered for the form fields in both tables. The tables are dynamically added to the webpage based upon different conditions. It is possible that no tables will be loaded, only 1 table, or both tables might load. In the future, other tables could be added. Each table comes from a different .net web control. Other than renaming the form fields to make sure they are unique across all user controls, is there a way to have JQuery act only on the intended form fields? In other words, could the table ID be incorporated into the JQuery code in a manner that does not become a nightmare to maintain later? <script> $(document).ready(function() { $("[id$=radio1_0]").click(function() { $("[id$=box1]").attr("value", ""); }); $("[id$=radio1_1]").click(function() { $("[id$=box1]").attr("value", "N/A"); }); </script> <table id="thing1"> <tr><td> <radiobuttonlist id="radio1"/> <listitem>yes</listitem> <listitem>no</listitem> </td></tr> <tr><td> <textbox id="box1"/> </td></tr> </table> <table id="thing2"> <tr><td> <radiobuttonlist id="radio1"/> <listitem>yes</listitem> <listitem>no</listitem> </td></tr> <tr><td> <textbox id="box1"/> </tr></td> </table>

    Read the article

  • Pull news from an RDF Feed using Ruby and Nokogiri?

    - by Christian
    I would like to pull the titleand description fields from the newsfeed at http://www.tagesschau.de/newsticker.rdf to feed them to the Mac's Text-to-Speech engine. My search for a nice Ruby Gem to do this has brought me to Nokogiri, but all examples that "pull something out" of a given XML seem to be centered around CSS somehow. Does anyone have any idea how to save the titleand description fields in an array?

    Read the article

  • Generic class for performing mass-parallel queries. Feedback?

    - by Aaron
    I don't understand why, but there appears to be no mechanism in the client library for performing many queries in parallel for Windows Azure Table Storage. I've created a template class that can be used to save considerable time, and you're welcome to use it however you wish. I would appreciate however, if you could pick it apart, and provide feedback on how to improve this class. public class AsyncDataQuery<T> where T: new() { public AsyncDataQuery(bool preserve_order) { m_preserve_order = preserve_order; this.Queries = new List<CloudTableQuery<T>>(1000); } public void AddQuery(IQueryable<T> query) { var data_query = (DataServiceQuery<T>)query; var uri = data_query.RequestUri; // required this.Queries.Add(new CloudTableQuery<T>(data_query)); } /// <summary> /// Blocking but still optimized. /// </summary> public List<T> Execute() { this.BeginAsync(); return this.EndAsync(); } public void BeginAsync() { if (m_preserve_order == true) { this.Items = new List<T>(Queries.Count); for (var i = 0; i < Queries.Count; i++) { this.Items.Add(new T()); } } else { this.Items = new List<T>(Queries.Count * 2); } m_wait = new ManualResetEvent(false); for (var i = 0; i < Queries.Count; i++) { var query = Queries[i]; query.BeginExecuteSegmented(callback, i); } } public List<T> EndAsync() { m_wait.WaitOne(); return this.Items; } private List<T> Items { get; set; } private List<CloudTableQuery<T>> Queries { get; set; } private bool m_preserve_order; private ManualResetEvent m_wait; private int m_completed = 0; private void callback(IAsyncResult ar) { int i = (int)ar.AsyncState; CloudTableQuery<T> query = Queries[i]; var response = query.EndExecuteSegmented(ar); if (m_preserve_order == true) { // preserve ordering only supports one result per query this.Items[i] = response.Results.First(); } else { // add any number of items this.Items.AddRange(response.Results); } if (response.HasMoreResults == true) { // more data to pull query.BeginExecuteSegmented(response.ContinuationToken, callback, i); return; } m_completed = Interlocked.Increment(ref m_completed); if (m_completed == Queries.Count) { m_wait.Set(); } } }

    Read the article

  • 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; } }

    Read the article

  • Does my GetEnumerator cause a deadlock?

    - by Scott Chamberlain
    I am starting to write my first parallel applications. This partitioner will enumerate over a IDataReader pulling chunkSize records at a time from the data-source. TLDR; version private object _Lock = new object(); public IEnumerator GetEnumerator() { var infoSource = myInforSource.GetEnumerator(); //Will this cause a deadlock if two threads lock (_Lock) //use the enumator at the same time? { while (infoSource.MoveNext()) { yield return infoSource.Current; } } } full code protected class DataSourcePartitioner<object[]> : System.Collections.Concurrent.Partitioner<object[]> { private readonly System.Data.IDataReader _Input; private readonly int _ChunkSize; public DataSourcePartitioner(System.Data.IDataReader input, int chunkSize = 10000) : base() { if (chunkSize < 1) throw new ArgumentOutOfRangeException("chunkSize"); _Input = input; _ChunkSize = chunkSize; } public override bool SupportsDynamicPartitions { get { return true; } } public override IList<IEnumerator<object[]>> GetPartitions(int partitionCount) { var dynamicPartitions = GetDynamicPartitions(); var partitions = new IEnumerator<object[]>[partitionCount]; for (int i = 0; i < partitionCount; i++) { partitions[i] = dynamicPartitions.GetEnumerator(); } return partitions; } public override IEnumerable<object[]> GetDynamicPartitions() { return new ListDynamicPartitions(_Input, _ChunkSize); } private class ListDynamicPartitions : IEnumerable<object[]> { private System.Data.IDataReader _Input; int _ChunkSize; private object _ChunkLock = new object(); public ListDynamicPartitions(System.Data.IDataReader input, int chunkSize) { _Input = input; _ChunkSize = chunkSize; } public IEnumerator<object[]> GetEnumerator() { while (true) { List<object[]> chunk = new List<object[]>(_ChunkSize); lock(_Input) { for (int i = 0; i < _ChunkSize; ++i) { if (!_Input.Read()) break; var values = new object[_Input.FieldCount]; _Input.GetValues(values); chunk.Add(values); } if (chunk.Count == 0) yield break; } var chunkEnumerator = chunk.GetEnumerator(); lock(_ChunkLock) //Will this cause a deadlock? { while (chunkEnumerator.MoveNext()) { yield return chunkEnumerator.Current; } } } } IEnumerator IEnumerable.GetEnumerator() { return ((IEnumerable<object[]>)this).GetEnumerator(); } } } I wanted IEnumerable object it passed back to be thread safe (the MSDN example was so I am assuming PLINQ and TPL could need it) will the lock on _ChunkLock near the bottom help provide thread safety or will it cause a deadlock? From the documentation I could not tell if the lock would be released on the yeld return. Also if there is built in functionality to .net that will do what I am trying to do I would much rather use that. And if you find any other problems with the code I would appreciate it.

    Read the article

  • Make a Method of the Business Layer secure. best practice / best pattern [.net/c#]

    - by gsharp
    Hi We are using ASP.NET with a lot of AJAX "Page Method" calls. The WebServices defined in the Page invokes methods from our BusinessLayer. To prevent hackers to call the Page Methods, we want to implement some security in the BusinessLayer. We are struggling with two different issues. First one: public List<Employees> GetAllEmployees() { // do stuff } This Method should be called by Authorized Users with the Role "HR". Second one: public Order GetMyOrder(int orderId) { // do sutff } This Method should only be called by the owner of the Order. I know it's easy to implement the security for each method like: public List<Employees> GetAllEmployees() { // check if the user is in Role HR } or public Order GetMyOrder(int orderId) { // check if the order.Owner = user } What I'm looking for is some pattern/best practice to implement this kind of security in a generic way (without coding the the if then else every time) I hope you get what i mean :-) Thanks for you help.

    Read the article

  • Make a Method of the Business Layer secure. best practice / best pattern

    - by gsharp
    We are using ASP.NET with a lot of AJAX "Page Method" calls. The WebServices defined in the Page invokes methods from our BusinessLayer. To prevent hackers to call the Page Methods, we want to implement some security in the BusinessLayer. We are struggling with two different issues. First one: public List<Employees> GetAllEmployees() { // do stuff } This Method should be called by Authorized Users with the Role "HR". Second one: public Order GetMyOrder(int orderId) { // do sutff } This Method should only be called by the owner of the Order. I know it's easy to implement the security for each method like: public List<Employees> GetAllEmployees() { // check if the user is in Role HR } or public Order GetMyOrder(int orderId) { // check if the order.Owner = user } What I'm looking for is some pattern/best practice to implement this kind of security in a generic way (without coding the the if then else every time) I hope you get what i mean :-)

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 303 304 305 306 307 308 309 310 311 312 313 314  | Next Page >