I am doing a project related to object's lifetime. I modified JVM code to force it to do garbage collection every 20000 allocations (i.e., every 20000 objects have been allocated). In my code, I used a global variable total_objs to track how many objects have been allocated so far. I added the ...

Hi,I have been having this problem since a long time and I am unable to find a proper solution nor explanation to this behaviour. The JVM seems to crash whenever I try to print through my java application. The crashing is not predictable. Sometimes it crashes right after I submit the first ...

Yesterday morning I found a Note Pad text file on my Desk top. The file was for an error report from Java Virual Machine. The mystery is, I don't have Java Virual Machine installed on this computer.Can anyone tell me how it got there? I'm a little more than just concerned.It's really a bit ...

Hi,Trying to get a simple String parameter from native to Java. As long as I don't access the passed parameters it works fine. As soon as I relate to the parameter (a String, trying to print it) I get the following exception:EXCEPTION_ACCESS_VIOLATION <0xc0000005)>at pc=...Java VM: Java ...

Is it possible to use wildcards in the classpath for KNI-Calls?I would like to use wildcard for jni-calls like for normal java-calls (java -classpath *.jar ...), but it is not working.JDK version is JDK 1.5.0 on Win32

Hi,I'am looking for JVM scheduler documentation.I couldn't find anything on java.com but i guess it exists, so can anybody provide some links please?Thanks in advance.

Hello,I am trying to run some Java Applications at a Linux Virtual Server. This Virtual Server limits virtual memory to 512MB using SWSofts Virtuzzo, so I cant use more than 512MB and it does not matter if that data is swapped or not. Starting a new Simple Hello World program that creates a ...

Hi-I have a piece of java code that looks like this:public static String addMe(Double a, Double b, Double result) {result = new Double(a.doubleValue() + b.doubleValue());return "Addition worked!!";}As you can see I want to return the result of the function as a function parameter and have the ...

Hello,I'm trying to create a simple Hello world dll. I have one method which returns a stirng, and this should be printed out by the Java class. This is the C++ code:#include <jni.h>#include "stdafx.h"#include "MyLib.h"JNIEXPORT jstring JNICALL Java_Test_getWord Java_Test_getWord(JNIEnv ...

what is exactely the line command in jdk 1.5 use to change the memory size

i use a Vector contain a lot of records the message out of memory errorapears how i can solve this problem.

Hello,I have created a software and lot of images used in this software. I want to bind all images in a dll. As microsoft binds card's images in cards.dll. After binding i want to use them. How can i access them from a dll. I know how to write a dll in java and how to use its methods but how ...

I have a C++ program that needs to create and call Java objects. I want it to have a single JVM that threads can attach to and detach from as needed. However, I'm having trouble seeing how multiple threads can be concurrently active with the same JVM. What it really boils down to is which ...

Hi everyone,sorry for my french accent. I would like if it's possible to have only one process of my program which turn on the system ?Thanks for your answers

I was told to put this here, so here it is.I have been trying to use JAWT (AWT Native Interface) and I keep getting an error (even when I try the examples that are in the api). When I call the JAWT_DrawingSurface lock method (locking a canvas) it always returns with JAWT_LOCK_ERROR. Does anyone ...

Hi,I need to debug java program where a method is implemented in C using JNI. How can I debug the C code? I am using eclipse to debug java code, is there any way to debug the method which is implemented in C using JNI?Thanks & Regards,Nasrin.N

Hello,A basic question about the jvm.dll library : I can't find any document explaining the difference between bin/client/jvm.dll and bin/server/jvm.dll both locatedin the j2sdk directory.Therefore, I don't really know which one I should use with tomcat run as a service.Thanks for your help ...

We are running Sun Fire T2000 with 32 processors, 16Gb total and 9Gb as java heap.At the moment we are trying to tune GC to reduce the pause time.Unfortunatly, we still are not able to model 'real behaviour' on our test server.All tuning is done on the production server, so we can't easly ...

Hi All,Will it help the performance/memory management if the objects/Strings are set to null in the finally block?Please help.Thanks,Raj

hi all,i deplyoed my web app into tomcat/jboss, i am reading dirver,url,user,pwd from web.xml, when running app it is giving NullPointerException, Not Recognising Type IV Driver, i made sure to set the class path, classes111.zip in sys env variable, i am using tomcat 4.x, jdk1.4.2. what are the ...

Hello is there a way to get a hWnd for a JTextField? I need this handle because i have to assign the IME to it for working with eastern asian languages.So far i found this code:JNIEXPORT jlong JNICALL Java_com_philips_ime_adapter_IME_getHwnd (JNIEnv *env, jclass clazz, jobject obj) {typedef ...

I believe the jobjects can be moved from time to time. What is probably happening right now that causes occasional crashing is that the jobject is moved after i pass it in as a parameter from 1 java thread to another in JNI. I guess one way to deal w/ this is to DisableGC from JVMPI or JVMTI. ...

I ran the following commands:JDK_HOME/bin/java -Dcom.sun.management.jmxremote -jar JDK_HOME/demo/jfc/Java2D/Java2Demo.jarwhere JDK_HOME is the directory containing the JDK 5.0. The Monitoring and Management Using JMX document provides detailed information on out-of-the-box remote management. To ...

Hi,I am currently investigating high CPU usage in my application. During certain times of the day the App sends out thousands of mails to the users. And during these peak times, the CPU usage is very high.In the course of this, I was monitoring the Weblogic server using the Admin Console's ...

We have an application that runs on a BEA Weblogic 8.1 application server. JVM is set as follows -Xms512K -Xmx1024K -XMaxPermSize 256KA minor GC runs about every 10 minutes and takes a fraction of a second. Our problem is that the application appears to hang every few days. The heap is usually ...

Hi, My app is often stopped abruptly and the JVM is crashed. But I can't found the error log file(hs_err_Pid*.log) on my computer. Is there no hs_err_pid*.log files generated? How to generate this file? Please help me, thank you?

Hi I am a novice in java world. I am very excited to learn tsr programming in java. I do not know wether it is possible or not in java. If it is possible please any one can help me.

Hello I have installed j2sd4_1.4.2.11 on linux machine : Here's the details: OS:Mandrake Linux release 10.0 (Official) for i586uname:Linux 2.6.12 #1 Sat Jul 9 21:38:32 GMT 2005 i686libc:glibc 2.3.3 NPTL 0.60 Java was running fine ..Two days ago, i encountered crashes when i ran simple ...

Hi People,I recently made some changes in my DEV. environment. An I am getting the following error when I run jboss, i.e. run.bat.\Java\jdk1.5.0_06\lib\tools.jar was unexpected at this time.I am running WindowsXP 64 bit on a Sun Ultra 20 Workstation. I had to switch from jdk1.5.0_06 64bit to ...

Hello,I want to upload a file of about 2GB size in the database. I am working on Struts framework and with Postgres8 and Oracle8i as database. When I try to upload it through my application it throws "Out of heap memory" error.Can anyone help me out to solve the problem? Thanks in ...

http://jroller.com/page/allex?entry=why_tableswitch_requires_more_thanEveryone knows that there is effective implementation of switch like this:public void switching( int l ){switch( l ){case 0: m0(); break;case 1: m1(); break;case 2: m2(); break;case 3: m3(); break;case 4: m4(); break;case 5: ...

The Stack class behavior is LIFO ,but it is extending the Vector then the stack is losing its behavior why sun would have done this.Is there any reason behind this.Thanks in advRegardsRaju

Hi everybody.I'm working with the JDK 1.5.I'de like to know if it's possible to do so that the garbage collector works less often. I mean I'd like that the garbage collector frees the memory only when it's really necessary (when the memory's full).Is there a way to do that ? I heard about ...

Dear Folks,I am struggling to find a solution to obtaining the relative lifetimes of runtime objects. For example, in a composition design pattern (whole-part relationship), it requires that the whole object must destroy all its parts before it destroys itself. Now how can I know, given two ...

Hi,In my C++ Native function i call ::Sleep(). This makes the appliation to crash sometime with some "" exception_voilation_error".Perhaps this is due to ::Sleep is a C++ function and if the current java thread gets a interrupt/notification then may be Thread.sleep() is expected instead of ...

Hello everybody...I was wondering if there is a way to convert a string into an integer ... but without using Integer.parseInt()... parseInt is very slow in performance, and since I have to read a file that contains millions of integers (read them as string, and then convert them to integers) ...

hi friends i know java do not have sizeo operator.then how can i find the size of a datatype

Hi,I'm looking for help maintaining an open-source project called Jace: http://sourceforge.net/projects/jace/I maintain the Windows port and I am basically looking for someone to help by supporting the Unix end of things. I would like to release Jace 1.1 soon but the Unix port is out of sync ...

Can anyone tell me what is an API?do i need to know them before i can test my application on an pda emulator ?

Can method written in java be called from a method written in c++?. that is c++ program can call a java method and how?

HiFew days ago I have found a new feature in java which is Java Annotation. I want to know about the java annotation. If any one know anything about this please reply as soon as possible.

Hello,I have a simple Java class with one native method, which returns a String. I've created the DLL with C++ .NET, and in case it returns a simple "Hello world", the application works.The problem is I need to create a COM+ object, and call its function. But the JVM breaks down even before ...

Hi all,We have developed some code calling a third party dll through JNI. The code runs fine on jre 1.4.2. When we test in on jre 1.5, the dll is giving us a heap memory exhausted message. We have set -Xmx to 1024m due to performance issue. If we lower -Xmx from 1024m to 912m, then the program ...

Hi,I am using the JDBj APIs provided by JDEdwards tool to connect to its database. All the API work successfully but I am having problems due to some threads getting created automatically when the connection is established using the API. Because of these threads the JVM is not getting ...

Hi.I am using JDK1.5.0_06 and Tomcat5 to develop a web service and I have wanted to tune our webservice using JDK options as below.-server -Xms1024m -Xmx1024m -XX:NewRatio=2 -XX:SurvivorRatio=1 However, when I inspect the generations via jconsole, only the NewRatio seems to be taking effect, ...

Hi!I've developed a java program that will run for about 5 days and produce a large quantity of data (the DB will be around 60 GB when done). The thing is that it stops running after 1 day or so and just send out the message "Morto" (meaning "dead"). Does anyone know why this is hapenning?The ...

What is the maximum heap size setting allowed for a single JVM on windows platform with Xmx parameter?Thanks.Ashfaque.

hi all, I had to show a list in sorting order, ofcoursce that can be done by, Collections.sort(collectionObj);the 'collectionObj' will be sorted in lexical order if it contains String Objectbut what if the collectionObj contains 'Myclass' Objects MyClass{FIrstName;LastName;Middle; String ...

How to set classpath if there is a n no of .jar filesThanks in advance

I have an application which runs in 1.4.2 and 1.5.0_05 JVM. Below are my heap settings which is same in both the versions.-Xms2048m -Xmx2048m -XX:+PrintGCDetails-XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=64m -XX:+UseParNewGC -XX:ParallelGCThreads=4 ...