Search Results

Search found 84599 results on 3384 pages for 'java util set'.

Page 303/3384 | < Previous Page | 299 300 301 302 303 304 305 306 307 308 309 310  | Next Page >

  • Java - Thread problem

    - by Yatendra Goel
    My question is related to all those methods(including Thread.sleep(...)) which throw InterruptedException. I found a statement on Sun's tutorial saying InterruptedException is an exception that sleep throws when another thread interrupts the current thread while sleep is active. Is that means that the interrupt will be ignored if the sleep is not active at the time of interrupt? Suppose I have two threads: threadOne and threadTwo. threadOne creates and starts threadTwo. threadTwo executes a runnable whose run method is something like: public void run() { : : try { Thread.sleep(10 * 1000); } catch (InterruptedException e) { return; } : : : // In the middle of two sleep invocations : : try { Thread.sleep(10 * 1000); } catch (InterruptedException e) { return; } : : } After thread creation, threadOne interrupts threadTwo. Suppose the threadTwo is in the middle of two sleep invocations at the time of interrupt (when no sleep method was active), then will the second sleep method throw InterrupteException as soon as it is invoked? If not, then will this interrupt will be ignored forever? How to be sure that threadTwo will always know about the interrupt (doesn't matter whether its one of the sleep method is active or not)?

    Read the article

  • Cast element in Java For Each statement

    - by Carl Summers
    Is it possible (or even advisable) to cast the element retrieved from a for each statement in the statement itself? I do know that each element in list will be of type . I.E.: List<BaseType> list = DAO.getList(); for(<SubType> element : list){ // Cannot convert from element type <BaseType> to <SubType> ... } rather than: List <BaseType> list = DAO.getList(); for(<BaseType> el : list){ <SubType> element = (<SubType>)el; ... }

    Read the article

  • copy file from one location to another location in linux using java program

    - by Mouli
    Using JSP am trying to move customer logo into another location in linux but its not working. thanks in advance Here is my program String customerLogo = request.getParameter("uploadCustomerLogo").trim(); StringBuffer absoluteFolderPath = new StringBuffer(); absoluteFolderPath.append("/zoniac"); absoluteFolderPath.append("/Companies/"); absoluteFolderPath.append("companyCode/"); absoluteFolderPath.append("custom/"); String destination = absoluteFolderPath.toString(); File sourcefile = new File(customerLogo); File destfile = new File(destination+sourcefile.getName()); FileUtils.copyFile(sourcefile,destfile);

    Read the article

  • Data table with legends in JfreeChart/Java

    - by TiNS
    Hi All, I am using JFreeChart to generate images. I am trying to create barchart like below. I am able to create it successfully without data table. I tried to get more information from the jfreechar forums and found this post. According to the post , its not supported by JfreeChart. Is it still not supported by jfreechart API ? If yes, can I use any other charting (open source) tool to generate chart with data table ? Thanks

    Read the article

  • Create java sandbox based on security policies

    - by argos
    I need to create environment to run potentially untrusted code. Program allowed to connect to preconfigured address:port and nothing else (even read the system time). I have compiled the class whitelist. I'd searched similar questions, but found only template that based on SecurityManager which AFAIK is deprecated. Can anybody give me a simple sample how to run code in sandbox based on security policies and AccessController?

    Read the article

  • UTF-8 character encoding in Java

    - by user332523
    Hello, I am having some problems getting some French text to convert to UTF8 so that it can be displayed properly, either in a console, text file or in a GUI element. The original string is HANDICAP+ES which is supposed to be HANDICAPÉES No matter how I tried converting it, it appears the same way. Any ideas on how I can do this conversion? Thanks, Cam

    Read the article

  • Java Inheritance - Getting a Parameter from Parent Class

    - by Aaron
    I'm trying to take one parameter from the parent class of Car and add it to my array (carsParked), how can i do this? Parent Class public class Car { protected String regNo; //Car registration number protected String owner; //Name of the owner protected String carColor; /** Creates a Car object * @param rNo - registration number * @param own - name of the owner **/ public Car (String rNo, String own, String carColour) { regNo = rNo; owner = own; carColor = carColour; } /** @return The car registration number **/ public String getRegNo() { return regNo; } /** @return A String representation of the car details **/ public String getAsString() { return "Car: " + regNo + "\nColor: " + carColor; } public String getColor() { return carColor; } } Child Class public class Carpark extends Car { private String location; // Location of the Car Park private int capacity; // Capacity of the Car Park - how many cars it can hold private int carsIn; // Number of cars currently in the Car Park private String[] carsParked; /** Constructor for Carparks * @param loc - the Location of the Carpark * @param cap - the Capacity of the Carpark */ public Carpark (String locations, int room) { location = locations; capacity = room; } /** Records entry of a car into the car park */ public void driveIn() { carsIn = carsIn + 1; } /** Records the departure of a car from the car park */ public void driveOut() { carsIn = carsIn - 1; } /** Returns a String representation of information about the carpark */ public String getAsString() { return location + "\nCapacity: " + capacity + " Currently parked: " + carsIn + "\n*************************\n"; } }

    Read the article

  • Java ternary operator and boxing Integer/int?

    - by Markus
    I tripped across a really strange NullPointerException the other day caused by an unexpected type-cast in the ternary operator. Given this (useless exemplary) function: Integer getNumber() { return null; } I was expecting the following two code segments to be exactly identical after compilation: Integer number; if (condition) { number = getNumber(); } else { number = 0; } vs. Integer number = (condition) ? getNumber() : 0; . Turns out, if condition is true, the if-statement works fine, while the ternary opration in the second code segment throws a NullPointerException. It seems as though the ternary operation has decided to type-cast both choices to int before auto-boxing the result back into an Integer!?! In fact, if I explicitly cast the 0 to Integer, the exception goes away. In other words: Integer number = (condition) ? getNumber() : 0; is not the same as: Integer number = (condition) ? getNumber() : (Integer) 0; . So, it seems that there is a byte-code difference between the ternary operator and an equivalent if-else-statement (something I didn't expect). Which raises three questions: Why is there a difference? Is this a bug in the ternary implementation or is there a reason for the type cast? Given there is a difference, is the ternary operation more or less performant than an equivalent if-statement (I know, the difference can't be huge, but still)?

    Read the article

  • How a thread should close itself in Java?

    - by Roman
    This is a short question. At some point my thread understand that it should suicide. What is the best way to do it: Thread.currentThread().interrupt(); return; By the way, why in the first case we need to use currentThread? Is Thread does not refer to the current thread?

    Read the article

  • Using interfaces in java..Newb question

    - by Rahul
    Suppose there in an interface Displaceable and a class Circle which implements Displaceable. Displaceable has a method named move() which of course is implemented in Circle. What would happen in the following scenario? Circle a = new Circle(..); Displaceable b = a; b.move() Would the object refer to the Circle's move method?

    Read the article

  • Java - Circular Garbage Collection

    - by aloh
    A <- B <- C <- D <- A... // A is firstNode, D is lastNode if ( length == 1 ) { firstNode = null; lastNode = null; firstNode.next = null; firstNode.prev = null; } else { Node secondNode = firstNode.next; Node secondToLast = lastNode.prev; firstNode.next = null; firstNode.prev = null; lastNode.next = null; lastNode.prev = null; secondNode.prev = null; secondToLast.next = null; firstNode = null; lastNode = null; } That should send everything in between as candidates for garbage collection, I hope?

    Read the article

  • Sending files from server to client in Java

    - by Lee Jacobson
    Hi, I'm trying to find a way to send files of different file types from a server to a client. I have this code on the server to put the file into a byte array: File file = new File(resourceLocation); byte[] b = new byte[(int) file.length()]; FileInputStream fileInputStream; try { fileInputStream = new FileInputStream(file); try { fileInputStream.read(b); } catch (IOException ex) { System.out.println("Error, Can't read from file"); } for (int i = 0; i < b.length; i++) { fileData += (char)b[i]; } } catch (FileNotFoundException e) { System.out.println("Error, File Not Found."); } I then send fileData as a string to the client. This works fine for txt files but when it comes to images I find that although it creates the file fine with the data in, the image won't open. I'm not sure if I'm even going about this the right way. Thanks for the help.

    Read the article

  • How to add deploy.jar to classpath?

    - by dma_k
    I am facing the problem: I need to add ${java.home}/lib/deploy.jar JAR file to classpath in the runtime (dynamically from java). The solution with Thread#setContextClassLoader(ClassLoader) (mentioned here) does not work because of this bug (if somebody can explain what is really a problem – you are welcome). The solution with -Xbootclasspath/a:"%JAVA_HOME%/jre/lib/deploy.jar" does not work well for me, because I want to have "pure executable jar" as a deliverable: no wrapping scripts please (more over %JAVA_HOME% may not be defined in user's environment in Windows for example, plus I need to write a script per platform) The solution with merging deploy.jar file into my deliverable works only if I make a build on Windows platform. Unfortunately, when the deliverable is produced on build server running on Linux, I got Linux-dependant JAR, which does not execute on Windows – it fails with the trace below. I have read How the Java Launcher Finds Classes and Java programming dynamics: Java classes and class loading articles but I've got no extra ideas, how to correctly handle this situation. Any advices or solutions are very welcomed. Trace: java.lang.NoClassDefFoundError: Could not initialize class com.sun.deploy.config.Config at com.sun.deploy.net.proxy.UserDefinedProxyConfig.getBrowserProxyInfo(UserDefinedProxyConfig.java:43) at com.sun.deploy.net.proxy.DynamicProxyManager.reset(DynamicProxyManager.java:235) at com.sun.deploy.net.proxy.DeployProxySelector.reset(DeployProxySelector.java:59) ... java.lang.NullPointerException at com.sun.deploy.net.proxy.DynamicProxyManager.getProxyList(DynamicProxyManager.java:63) at com.sun.deploy.net.proxy.DeployProxySelector.select(DeployProxySelector.java:166)

    Read the article

  • Right method to build a online whiteboard - JAVA

    - by Nikhar Sharma
    I am building a whiteboard, which would have a server(teacher) and clients(students). Teacher would draw something on his side, which will be shown exactly same to the students. I want to know which component i should use to do the drawing? i am currently drawing on JPanel . I want the screen of Server gets copied on the clients, so for that what could be the right method to do this? option1: i save the JPanel as image, and send thru socket, and loads it on the screen of client, also it always saves the background image only, not what the user has drawn onto it. OR option2: both server and client JPanel dimensions are same, so i just send the new coordinates drawn everytime thru socket, with some protocol to understand whether it is rubber or pencil.. Any help would be appreciated.

    Read the article

  • Java: getInputMap(WHEN_IN_FOCUSED_WINDOW) from within JInternalFrame

    - by gerardlouw
    I have a component inside a JInternalFrame which needs to perform actions when keys are pressed within the JInternalFrame's parenting window. Using InputMap/ActionMap would be ideal, but the getInputMap(WHEN_IN_FOCUSED_WINDOW) of the component returns an InputMap that treats the JInternalFrame as the "focused window", rather than its parenting window. Any solutions or ideas?

    Read the article

  • customising serialisation of java collections using xstream

    - by Will Goring
    I have an object that needs to be serialised as XML, which contains the following field: List<String> tags = new List<String>(); XStream serialises it just fine (after some aliases) like this: <tags> <string>tagOne</string> <string>tagTwo</string> <string>tagThree</string> <string>tagFour</string> </tags> That's OK as far as it goes, but I'd like to be able to rename the <string> elements to, say, <tag>. I can't see an obvious way to do that from the alias documentation on the XStream site. Am I missing something obvious?

    Read the article

  • Shallow Copy in Java

    - by Vilius
    Hello there! I already know, what a shallow copy is, but I'm not able to impliment it. Here's a short example. public class Shallow { String name; int number; public Shallow (String name, int number) { this.name = name; this.number = number; } } Test the implementation ... public class ShallowTest { public static void main (String[] args) { Shallow shallow = new Shallow("Shallow", 123); Shallow shallowClone = new Shallow(shallow); shallowClone.name = 'Peter'; shallowClone.number = 321; System.out.println(shallow.name + " - " + shallow.number); } } As I purpose, just the reference of the non primitive datatype String would be copied, so that by calling "shallowClone.name = 'Peter';" I would also change the name of "shallow". Am I right? But somehow, it just does not want to work ....

    Read the article

< Previous Page | 299 300 301 302 303 304 305 306 307 308 309 310  | Next Page >