Search Results

Search found 46894 results on 1876 pages for 'java native interface'.

Page 256/1876 | < Previous Page | 252 253 254 255 256 257 258 259 260 261 262 263  | Next Page >

  • Java: is Exception class thread-safe?

    - by Vilius Normantas
    As I understand, Java's Exception class is certainly not immutable (methods like initCause and setStackTrace give some clues about that). So is it at least thread-safe? Suppose one of my classes has a field like this: private final Exception myException; Can I safely expose this field to multiple threads? I'm not willing to discuss concrete cases where and why this situation could occur. My question is more about the principle: can I tell that a class which exposes field of Exception type is thread-safe? Another example: class CustomException extends Exception { ... } Is this class thread-safe?

    Read the article

  • How to use this Color's constructor? Java

    - by MaxMackie
    According to Oracle's site, the class Color has a constructor that accepts a single int value which represents an RGB value. http://download.oracle.com/javase/1.4.2/docs/api/java/awt/Color.html#Color(int) An RGB color is actually three different numbers ranging from 0-255. So combining them together to make one int would look like this: White 255,255,255 White 255255255 Right? So I pass this to the constructor and get a vibrant teal color. What am I doing wrong? What haven't I understood?

    Read the article

  • Java library for converting Word documents to PDFs or images

    - by mieze
    Hey there What I need to do is convert Microsoft Word .doc files to PDFs or images. This has to occur in Java. I have done a fair bit of investigation already. I've tried Davisor Publishor but it doesn't give me the accuracy that I need - for instance text overlapping in the output document. Adobe has something called LiveCycle. Anyone tried this? It looks quite massive and a bit of overkill (its an "integrated server solution"). Sounds expensive. Saying that, it doesn't have to be free, or cheap. Even if you just know some names, please shout them my way. Many thanks in advance. Doug

    Read the article

  • Java init method

    - by Johan Sjöberg
    What's a good way to make sure an init method is invoked in java? The alternatives I see are Don't test it, let the method fail by itself, likely by a NullPointerException Test if method was initialized or throw public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } ... } Delagate public void foo() { if (!inited) { throw new IllegalArgumentException("not initalized"); } fooInternal(); } private void fooInternal(){ ... }; Always init, and make init a noop otherwise public void foo() { init(); ... } public void init() { if(!inited) { ... } } Silently init public void foo() { if (!inited) { init(); } ... } Most of these approaches are very verbose and decreases overall readability.

    Read the article

  • Java: JPA classes, refactoring from Date to DateTime

    - by bguiz
    With a table created using this SQL Create Table X ( ID varchar(4) Not Null, XDATE date ); and an entity class defined like so @Entity @Table(name = "X") public class X implements Serializable { @Id @Basic(optional = false) @Column(name = "ID", nullable = false, length = 4) private String id; @Column(name = "XDATE") @Temporal(TemporalType.DATE) private Date xDate; //java.util.Date ... } With the above, I can use JPA to achieve object relational mapping. However, the xDate attribute can only store dates, e.g. dd/MM/yyyy. How do I refactor the above to store a full date object using just one field, i.e. dd/MM/yyyy HH24:mm?

    Read the article

  • Java - Array's length property

    - by The New Idiot
    We can determine the length of an ArrayList<E> using its public method size() , like ArrayList<Integer> arr = new ArrayList(10); int size = arr.size(); Similarly we can determine the length of an Array object using the length property String[] str = new String[10]; int size = str.length; Whereas the size() method of ArrayList is defined inside the ArrayList class , where is this length property of Array defined ? Is it implemented by JVM or does it reside in any Java API class file ?

    Read the article

  • Accessing every child class of parent class in Java

    - by darkie15
    Hi All, I have to implement a logic whereby given a child class, I need to access its parent class and all other child class of that parent class, if any. I did not find any API in Java Reflection which allows us to access all child classes of a parent class. Is there any way to do it? Ex. class B extends class A class C extends class A Now using class B, I can find the superclass by calling getSuperClass(). But is there any way to find all the child classes once I have the parent class i.e. class B and class C?? Regards, darkie

    Read the article

  • GroupLayout giving error with java swing

    - by Name
    I am getting some long list of error . Can anyone suggest me where i am wrong with group layout layout.setHorizontalGroup( layout.createSequentialGroup() .addComponent(new JLabel("Enter Book Name")) .addComponent(new JTextField("TextField", 20)) ); ERROR Exception in thread "main" java.lang.IllegalStateException: javax.swing.JTextField[,0,0,0x0,invalid,layout=javax.swing.plaf.basic.BasicTextUI$UpdateHandler,alignmentX=0.0,alignmentY=0.0,border=javax.swing.plaf.BorderUIResource$CompoundBorderUIResource@3d0bbf9e,flags=296,maximumSize=,minimumSize=,preferredSize=,caretColor=sun.swing.PrintColorUIResource[r=51,g=51,b=51],disabledTextColor=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],editable=true,margin=javax.swing.plaf.InsetsUIResource[top=0,left=0,bottom=0,right=0],selectedTextColor=sun.swing.PrintColorUIResource[r=51,g=51,b=51],selectionColor=javax.swing.plaf.ColorUIResource[r=184,g=207,b=229],columns=20,columnWidth=0,command=,horizontalAlignment=LEADING] is not attached to a vertical group at javax.swing.GroupLayout.checkComponents(Unknown Source) at javax.swing.GroupLayout.prepare(Unknown Source)

    Read the article

  • Using type hints in Clojure for Java return values

    - by mikera
    I'm working on some Java / Clojure interoperability and came across a reflection warning for the following code: (defn load-image [resource-name] (javax.imageio.ImageIO/read (.getResource (class javax.imageio.ImageIO) resource-name))) => Reflection warning, clojure/repl.clj:37 - reference to field read can't be resolved. I'm surprised at this because getResource always returns a URL and I would therefore expect the compiler to use the appropriate static method in javax.imageio.ImageIO/read. The code works fine BTW so it is clearly finding the right method at run time. So two questions: Why is this returning a reflection warning? What type hint do I need to fix this?

    Read the article

  • Good XMPP Java Libraries for server side?

    - by Taylor Gautier
    I was hoping to implement a simple XMPP server in Java. What I need is a library which can parse and understand xmpp requests from a client. I have looked at Smack (mentioned below) and JSO. Smack appears to be client only so while it might help parsing packets it doesn't know how to respond to clients. Is JSO maintained it looks very old. The only promising avenue is to pull apart Openfire which is an entire commercial (OSS) XMPP server. I was just hoping for a few lines of code on top of Netty or Mina, so I could get started processing some messages off the wire.

    Read the article

  • How do I copy an object in Java?

    - by Veera
    Consider the below code: DummyBean dum = new DummyBean(); dum.setDummy("foo"); System.out.println(dum.getDummy()); // prints 'foo' DummyBean dumtwo = dum; System.out.println(dumtwo.getDummy()); // prints 'foo' dum.setDummy("bar"); System.out.println(dumtwo.getDummy()); // prints 'bar' but it should print 'foo' So, I want to copy the 'dum' to dumtwo' and I want to change 'dum' without affecting the 'dumtwo'. But the above code is not doing that. When I change something in 'dum', the same change is happening in 'dumtwo' also. I guess, when I say dumtwo = dum, Java copies the reference only. So, is there any way to create a fresh copy of 'dum' and assign it to 'dumtwo' ?

    Read the article

  • Interning strings in Java

    - by Tiny
    The following segment of code interns a string. String str1="my"; String str2="string"; String concat1=str1+str2; concat1.intern(); System.out.println(concat1=="mystring"); The expression concat1=="mystring" returns true because concat1 has been interned. If the given string mystring is changed to string as shown in the following snippet. String str11="str"; String str12="ing"; String concat11=str11+str12; concat11.intern(); System.out.println(concat11=="string"); The comparison expression concat11=="string" returns false. The string held by concat11 doesn't seem to be interned. What am I overlooking here? I have tested on Java 7, update 11.

    Read the article

  • Java Program Design Layout Recommendations?

    - by Leebuntu
    I've learned enough to begin writing programs from scratch, but I'm running into the problem of not knowing how to design the layout and implementation of a program. To be more precise, I'm having difficulty finding a good way to come up with an action plan before I dive in to the programming part. I really want to know what classes, methods, and objects I would need beforehand instead of just adding them along the way. My intuition is leading me to using some kind of charting software that gives a hierarchal view of all the classes and methods. I've been using OmniGraffle Pro and while it does seem to work somewhat, I'm still having trouble planning out the program in its entirety. How should I approach this problem? What softwares out there are available to help with this problem? Any good reads out there on this issue? Thanks so much! Edit: Oh yeah, I'm using Eclipse and I code mainly in Java right now.

    Read the article

  • How to implement file transfer with Java sockets?

    - by ZeKoU
    Hello, I am working on a chat implementation with Java sockets. I have focused on few functionalities, like authentication, one person chat and a group chat. I was thinking about adding file transfer functionality, and I wonder what's the good practice about this. Should I have separate socket on the server with different port listening just for file transfers? Right now input and output streams that I get from server socket are binded to Scanner and PrintWriter objects respectively, so I find it hard to use that for file transfer. Any patterns you guys could recommend or give me good recommendations are very appreciated. Thanks, ZeKoU

    Read the article

  • new line in java

    - by user225269
    Java newbie here, I'm having trouble setting a new line in this code: String FnameTextboxText = FnameTextbox.getText(); String LastnameTextboxText = LastnameTextbox.getText(); String CourseTextboxText = CourseTextbox.getText(); Summary.setText("Firstname:" + " " + FnameTextboxText + "\nLastname:" + " " + LastnameTextboxText + "\nCourse:" + " " + CourseTextboxText); Also tried something like: "\n" + "Lastname" But its no good. Do you have any idea on how to make new lines. So that it'll look like this; Firstname: x Lastname: y Course: Z Using netbeans 6.8. On windows.

    Read the article

  • DataGrid In Java Struts Web Application

    - by Anand
    Hi After scouring the web I have edited my question from the one below to what it is now. Ok I seem to understand that I don't need all the capabilities of excel right now. I think i am satisfied having a data grid to display data. Basically i am working on Struts 2 and I wat my jsp page to have an excel like feel and hence looks like even a datagrid is sufficient. I came across This Technology I am not sure whether I must go ahead and use it. Any other suggestions, alternatives are welcome The older version of the question "I have a java web application running on windows currently. I may host it in future in a Linux Server. My application allows people to upload data. I want to display the data they have uploaded in an excel file and render it in a portion of my webpage. How do I go about this ?"

    Read the article

  • Eclipse Java code Format

    - by Jayesh
    I am not that much aware of Eclipse Shortcuts. I copied code from some link and I pasted in Eclipse Indigo but it is coming like "public String doLogin() throws ApplicationException{ long executionStartTime = System.cu... }" I want to format it in java style like public String doLogin() throws ApplicationException{ long executionStartTime = System.cu... } I google it and found few shortcuts like, "Shift + Tab" , "Ctrl + I", "Ctrl + Shift + F". but is not giving me the behavior I want. is there I need to add custom formatter or I am expecting more.

    Read the article

  • Reverse massive text file in Java

    - by DanJanson
    What would be the best approach to reverse a large text file that is uploaded asynchronously to a servlet that reverses this file in a scalable and efficient way? text file can be massive (gigabytes long) can assume mulitple server/clustered environment to do this in a distributed manner. open source libraries are encouraged to consider I was thinking of using Java NIO to treat file as an array on disk (so that I don't have to treat the file as a string buffer in memory). Also, I am thinking of using MapReduce to break up the file and process it in separate machines. Any input is appreciated. Thanks. Daniel

    Read the article

  • A simple way (in java) to remove headers

    - by Andersson Melo
    I need remove non-xml tags from file generated by another program. The file is some like this: Executing Command - Blah.exe ... -----Command Output----- HTTP/1.1 200 OK Connection: close Content-Type: text/xml <?xml version="1.0"?> <testResults> <right>7</right> <wrong>4</wrong> <ignores>0</ignores> <exceptions>0</exceptions> </finalCounts> </testResults> Exit-Code: 15 How to remove the non-xml text easily in java?

    Read the article

  • Problem using AJAX with a Java Applet

    - by diglettpotato
    I currently have a Java Applet which contains a method callfromjs(). Javascript calls this method from the applet so that I don't have to deal with the clunky applet GUI, and then I can create the responses on the DOM easily from javascript. The problem is that the browser hangs while first loading the applet. To get around this, I figured I could use AJAX. The AJAX calls a PHP file which contains callfromjs(). The problem is that the request returns because it's PHP, and it doesn't wait for callfromjs() to retrieve the content. On to my questions: Is there a better way to handle this? If this method seems ok, how can I force the request not to return until the javascript is finished calling the method from the applet?

    Read the article

  • Designing constructors around type erasure in Java

    - by Internet Friend
    Yesterday, I was designing a Java class which I wanted to be initalized with Lists of various generic types: TheClass(List<String> list) { ... } TheClass(List<OtherType> list) { ... } This will not compile, as the constructors have the same erasure. I just went with factory methods differentiated by their names instead: public static TheClass createWithStrings(List<String> list) public static TheClass createWithOtherTypes(List<OtherType> list) This is less than optimal, as there isn't a single obvious location where all the different options for creating instances are available. I tried to search for better design ideas, but found surprisingly few results. What other patterns exist for designing around this problem?

    Read the article

  • Simple Java question

    - by user322102
    Hi All I new to java so bare with me if this is a ridiculously simple question but I am curious about this method call which has {code} being taken in - see code below for an example in the method addSelectionListener. What is the purpose of this? I have been looking through docs for an explaination but cant seem to find what this practice is called never mind any useful information. setStatusLine.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent e) { String message = "I would like to say hello to you."; if (pressed) { message = "Thank you for using me"; } setStatusLine(message); pressed = !pressed; } }); Thanks for any help or insights that can be offered

    Read the article

  • patching java reflect calls using AOP

    - by Oleg Pavliv
    I don't have a lot of experience with Jboss AOP and I'm just curious if it's possible to replace all calls like Field f = foo.class.getDeclaredField("bar"); f.set(object, value); with something like Field f = foo.class.getDeclaredField("bar"); FieldSetCaller.invoke(f, object, value); using Jboss AOP. FieldSetCaller is my own class. I need to replace all Field.set calls on the fly, without recompiling the code. Some third -party code I even cannot recompile because I don't have the source. I can achieve this using java asm framework and I'm wandering if Jboss AOP can do it as well. Just for information - my code is running on Jboss server 4.3.0

    Read the article

  • Java Archtecture Decision !!

    - by santiagobasulto
    Hi everybody! I'm developing a medium Java app, and i'm facing a small problem due to my lack of expirience. I've a custom DAO, which gets "Article" objects from the DataBase. I've the Article class, and the DAO has a method called getArticle(int id), this method returns an Article. The Article has a Category object, and i'm using lazy loading. So, when i request for an Article Category (Article a = new Article(); a.getCategory();) the Article class gets the Category from the DAO and then returns it. I'm now thinking to cache it, so when i request multiple times to an Article's category, the database is only queried one time. My question is: where should i put that cache? I can put it on the Article class (in the DTO), or i can put it on the DAO class. What do you say? Thanks!

    Read the article

  • New/strange Java "try()" syntax?

    - by Ali
    While messing around with the custom formatting options in Eclipse, in one of the sample pieces of code, I say code as follows: /** * 'try-with-resources' */ class Example { void foo() { try (FileReader reader1 = new FileReader("file1"); FileReader reader2 = new FileReader("file2")) { } } } I've never seen try used like this and I've been coding in Java for 9 years! Does any one know why you would do this? What is a possible use-case / benefit of doing this? An other pieces of code I saw, I thought was a very useful shorthand so I'm sharing it here as well, it's pretty obvious what it does: /** * 'multi-catch' */ class Example { void foo() { try { } catch (IllegalArgumentException | NullPointerException | ClassCastException e) { e.printStackTrace(); } } }

    Read the article

< Previous Page | 252 253 254 255 256 257 258 259 260 261 262 263  | Next Page >