Invoking java exe from C++ code

Most of my applications are in c++, i have one application in java.
How can I invoke the java application(jar) from c++ code?

Hi We can do this by using EXTERN C functionality provided by c++ ,
by using this we can call the Java functions from Java .class file.
or .jar file.
(for java developers ......its similer to JNI)
if you want more details aboth such code just search it on web , you will get number of programs here.
Thanks,
-Akshay

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Problems to invoke java.exe from Java application, but ok for javac.exe??

How to invoke DOS application from Java application??
I try the following but it didn't work to invoke command prompt and java.exe, it
is working to invoke javac.exe. Any ideas why??
import java.io.*;
public class CallJavaTest
{ public static void main(String[] args)
{ try
Runtime.getRuntime().exec("C:\\WINNT\\System32\\cmd.exe"); //doesn't work!!
Runtime.getRuntime().exec("javac "+ "Test.java"); //it works!!
Runtime.getRuntime().exec("java "+ "Test"); //doesn't work!!
catch(IOException e)
System.out.println(e);

hi
String[] cmd = {"cmd","/c", "start",enteryourdoscommandhere};
Runtime rt = Runtime.getRuntime();
Process ps = rt.exec(cmd);
ps.waitFor();
int ev = ps.exitValue();
it works for my winXP.
hope it can helps and not too late ..

How to terminate a java thread from c++ code?

Hi,
I made a screensaver which loads a jvm, forks a thread running a java class, wait until user's action(i.e. mouse move/click keyboard input), then terminate the java thread.
However, I met a problem, How to terminate a running java thread from c++ code?
Here is my code, but it does not work: (even after the terminate is called, jvm throws an error)
JNIEnv* env;
JavaVM* jvm;
HANDLE hThread; //handle for the startThread
unsigned __stdcall startThread(void *arg)
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     jmethodID mainId;
     jint          res;
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     jstring str;
     jobjectArray args;
     int i=0;
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     if (env->ExceptionOccurred()) {
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Here is the main method:
First create the jvm and load the thread. then tries to terminate the thread, but failed here
switch (msg)
{ case WM_CREATE:
          JavaVMOption options[NUMBEROFOPTIONS];
          JavaVMInitArgs vmargs;
          jint rc;
          vmargs.version = JNI_VERSION_1_4; /* version 1.4 */
          vmargs.options = options;
          vmargs.nOptions = NUMBEROFOPTIONS;
          vmargs.ignoreUnrecognized = JNI_FALSE;
          rc=JNI_CreateJavaVM( &jvm, (void **)&env, &vmargs ); /* create JVM */
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          unsigned int threadId = -1;
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Note, after the thread "startThread" runs, it has an infinite loop and will not terminate, until the user clicks to terminate.(I didn't call jvm->DetachCurrentThread();_endthreadex(0); in the "startThread" because the java thread will not terminate by itself)
Thus, the only way to terminate the thread is to call closehandle(hthread) in the main thread, which may cause jvm to throw an error.
Do you know how to terminate a java thread safely???
Thanks a lot

Assuming that your java thread is in a loop of some kind. Such as
int i=1; /* I tried using a boolean, I just could not get my C++ env, to change this value. So i decided to use an int */
run {
while(i)
isdfjsdfj
void seti()
i=0
So, B/4, i call destroyVM in my C++ code, i call this seti(). so the loop terminates, therefore my thread finishes executing and ends.
Hope this helps
tola.

Invoking java methods from C/C++ on the machine with different JREs

I implemented Windows NT Service instantiating JVM and invoking several java methods. Everything works but I have an issue with running the service on the machine where multiple different versions of JRE have been installed. The service is calling java methods that require JRE 1.3 or later so I wrote the code that is setting system PATH from within the service based on the configuration stored in the external file. The problem is that the service requires jvm.dll to be in the PATH prior lunching it since this library is instantiated through the implicit linking. When I put jvm.dll in the same path as the service binary I can lunch it but JNI_CreateJavaVM fails and returns -1. This happens even if JRE 1.3 is in the system PATH prior lunching the service.
Everything works if the system PATH contains references to JRE 1.3 and jvm.dll is removed from the service's directory.
I am looking for an advice on what is the proper way to deal with invoking java methods from the C/C++ executable in the environment with different versions of JRE.
Thanks, Kris.

Here's a way I have done what you are asking about:
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Following is some code that I used to handle a dll of my own in this manner. You can decide if you want to write a "wrapper" dll, or if you find it simpler to approach the jvm.dll in this way.
// Define pointer type for DLL entry point.
     typedef void JREPDLL_API (*EXECUTEREQUEST)(char*, Arguments&);
// Set up path, load dll, and pass everything off to it.
HINSTANCE javaServer = javaServer = LoadLibrary("jrepdll.dll");
if (javaServer != NULL) {
EXECUTEREQUEST executeRequest = (EXECUTEREQUEST)GetProcAddress(javaServer, "ExecuteRequest");
if (executeRequest != NULL) {
if (argc == 1)
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Here's some code for how to edit the PATH:
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char *appendPt;
char *newPath;
char *path;
          char tmp[_MAX_PATH];
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path = getenv("PATH");
          // Allocate space for an edited path setting.
          if (path != NULL)
               newPath = (char*)malloc((_MAX_PATH * 2) + strlen(path));
          else
               newPath = (char*)malloc((_MAX_PATH * 2));
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          strcpy(tmp, filepath);
          appendPt = strstr(tmp, "dbin\\jreplicator");
          appendPt[0] = '\0';
sprintf(newPath, "PATH=%sjava\\jre1.2.2\\bin;%sjava\\jre1.2.2\\bin\\classic", tmp, tmp);
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// If there is anything, append it.
if (path != NULL) {
     strcat(newPath, ";");
     strncat(newPath, path, (sizeof(newPath) - strlen(newPath) - 2));
// Set new PATH value.
_putenv(newPath);
          free(newPath);

Finally i found a way to invoke a .exe from flex

hi
Months before i had posted a question in the forum about
invoking a .exe from FLEX...
now after trying out many things from LCDS to java...I
finally found a way to do it....
I ve put up the link here...
Flex
Solution

google
setup msn mail as pop3 on iphone
google
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How to start java.exe from a java program in windows ?

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Manish

Hi Manish,
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I only know we can use JNI to invoke native libraries
from Java and I have never used JNI to invoke Java
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I am going to look through the tutorial you
recommended.The last tutorial. I've only fiddled with it, as it was a bitch. If you don't need to use Suns JVM, I recomend using CNI & GCJ [ http://gcc.gnu.org/java/ ], as it is much neater.
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pubilc static void main( String args[] ) {
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Hello everyone,
Are there any approaches to invoke Java libraries from C/C++?
Thanks in advance,
George

I only know we can use JNI to invoke native libraries
from Java and I have never used JNI to invoke Java
libraries from native applications (C/C++ programs).
I am going to look through the tutorial you
recommended.The last tutorial. I've only fiddled with it, as it was a bitch. If you don't need to use Suns JVM, I recomend using CNI & GCJ [ http://gcc.gnu.org/java/ ], as it is much neater.
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pubilc static void main( String args[] ) {
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Can i call java program from VC++ code...... Urgent!

hi,
I have VC++ code.
I want to run java program from VC++ (SDK).
Can I call it?
plz help it's urgent....
thanks in advance...

We do it all the time using the JNI invocation API (this is actually how the java.exe application works).
Here's a tutorial I just found (not sure how good it is, but it should get you going):
http://www.inonit.com/cygwin/jni/invocationApi/
One note: If you are going to be invoking the JVM from different threads in your native app, there is some special handling you will have to do - the above tutorial doesn't address this scenario (a dig through the JNI docs should help with that one, though).
Cheers,
- K

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thanks

HI
I was able to add a canvas3D to a webbrowser via an applet. I suppose you can always invoke an applet from a JSP.
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Hi, there:
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Here, I would like to have the involked java code to get
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How to invoke Java class from post.POST.jsp

Hi All,
I am trying to invoke a simple java method from post.POST.jsp
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29:
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2. If it is implemented, Change the bundle version in bnd file and make a new build. Then from felix console verify the latest version reflected in the bundles.
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[1] com.day.test.datasource.DatasourceUtil
[2]   com.day.test.datasource.DatasourceUtilImpl

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class is part of a package and indirectly makes a JMS request-reply call
via other helper classes.
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unlike the Oracle JVM Aurora, the JVMs don't detect a deadlock.
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Did you try issusing a commit and then trying again in Toad SQL Window?
The advice is to contact support:
ORA-29516: Aurora assertion failure: string
Cause: An internal error occurred in the Aurora module.
Action: Contact Oracle Worldwide Support.

Invoking java exe from C++ code

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