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threadhead

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  1. Hey thanks and sorry for wasting your time. Sample works like a charm. Great product, keep up the good work!
  2. Hi. I ran your sample, specifically from C:\JET\samples\Invocation\cMain and all was well. Then I decided to pass some arguments and make sure that worked. Unfortunately, it did not. I modified your test code so that 'foo' accepts 3 strings. Every thing compiles nicely and I inspect the jobjectArray before passing it in arg#4 of the JNI API method CallStaticVoidMethod(). The results? The strings are all null inside Java (Null Pointer Exception): C:\JET\samples\Invocation\cMainModified>test_args MyDll.dll loaded JET RT initialized Class MyClassInDll found object of 'MyClassInDll' created instance method 'ifoo' called Allocated String Array SetObjectArrayElements Allocated value=> arg one Allocated value=> arg two Allocated value=> arg three In Java: static method 'foo' called Exception in thread "main" java.lang.NullPointerException at java.lang.String.charAt(String.java:576) at MyClassInDll.foo(MyClassInDll.java:16) =============== Is it my code or yours? My additions to the sample are in red. Here is the Java code: public class MyClassInDll { public MyClassInDll() { System.out.println("object of 'MyClassInDll' created"); } public void ifoo() { System.out.println("instance method 'ifoo' called"); } public static void foo( String one, String two, String three ) { System.out.println("In Java: static method 'foo' called"); System.out.println("ARG one charAt(0) => " + one.charAt(0) ); System.out.println("ARG two => " + two); System.out.println("ARG three => " + three ); } } Here is the modified c code: #include <jni.h> #ifdef __linux__ #include <dlfcn.h> #define HANDLE void* #define LoadLibrary(x) dlopen(x, RTLD_LAZY) #define GetProcAddress(x,y) dlsym(x,y) #else #include <windows.h> #endif char dllname[] = #ifdef __linux__ "./libMyDll.so"; #else "MyDll.dll"; #endif /* * Load dll. */ HANDLE loadDll(char* name) { HANDLE hDll = LoadLibrary (name); if (!hDll) { printf ("Unable to load %s\n", name); exit(1); } printf ("%s loaded\n", name); return hDll; } jint (JNICALL * JNI_GetDefaultJavaVMInitArgs_func) (void *args); jint (JNICALL * JNI_CreateJavaVM_func) (JavaVM **pvm, void **penv, void *args); /* * Initialize JET run-time. */ void initJavaRT(HANDLE myDllHandle, JavaVM** pjvm, JNIEnv** penv) { int result; JavaVMInitArgs args; JNI_GetDefaultJavaVMInitArgs_func = (jint (JNICALL *) (void *args)) GetProcAddress (myDllHandle, "JNI_GetDefaultJavaVMInitArgs"); JNI_CreateJavaVM_func = (jint (JNICALL *) (JavaVM **pvm, void **penv, void *args)) GetProcAddress (myDllHandle, "JNI_CreateJavaVM"); if(!JNI_GetDefaultJavaVMInitArgs_func) { printf ("%s doesn't contain public JNI_GetDefaultJavaVMInitArgs\n", dllname); exit (1); } if(!JNI_CreateJavaVM_func) { printf ("%s doesn't contain public JNI_CreateJavaVM\n", dllname); exit (1); } memset (&args, 0, sizeof(args)); args.version = JNI_VERSION_1_2; result = JNI_GetDefaultJavaVMInitArgs_func(&args); if (result != JNI_OK) { printf ("JNI_GetDefaultJavaVMInitArgs() failed with result %d\n", result); exit(1); } /* * NOTE: no JVM is actually created * this call to JNI_CreateJavaVM is intended for JET RT initialization */ result = JNI_CreateJavaVM_func (pjvm, (void **)penv, &args); if (result != JNI_OK) { printf ("JNI_CreateJavaVM() failed with result %d\n", result); exit(1); } printf ("JET RT initialized\n"); } /* * Look for class. */ jclass lookForClass (JNIEnv* env, char* name) { jclass clazz = (*env)->FindClass (env, name); if (!clazz) { printf("Unable to find class %s\n", name); exit(1); } printf ("Class %s found\n", name); return clazz; } /* * Create an object and invoke the "ifoo" instance method */ void invokeInstanceMethod (JNIEnv* env, jclass myClassInDll) { jmethodID MID_init, MID_ifoo; jobject obj; MID_init = (*env)->GetMethodID (env, myClassInDll, "<init>", "()V"); if (!MID_init) { printf("Error: MyClassInDll.<init>() not found\n"); return; } obj = (*env)->NewObject(env, myClassInDll, MID_init); if (!obj) { printf("Error: failed to allocate an object\n"); return; } MID_ifoo = (*env)->GetMethodID (env, myClassInDll, "ifoo", "()V"); if (!MID_ifoo) { printf("Error: MyClassInDll.ifoo() not found\n"); return; } (*env)->CallVoidMethod (env, obj, MID_ifoo); } /* * Invoke the "foo" static method */ void invokeStaticMethod( JNIEnv* env, jclass myClassInDll ) { jmethodID MID_foo; jobjectArray jObjArray; jstring jArgOne; jstring jArgTwo; jstring jArgThree; jstring jStrVar; int i; MID_foo = (*env)->GetStaticMethodID(env, myClassInDll, "foo", "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V" ); if (!MID_foo) { printf("\nError: MyClassInDll.foo() not found\n"); return; } jObjArray = (*env)->NewObjectArray( env, 3, (*env)->FindClass( env, "java/lang/String" ), NULL ); if( NULL == jObjArray ) { printf( "\nError: Could not allocate NewObjectArray." ); return ; } printf( "\nAllocated String Array\n" ); jArgOne = (*env)->NewStringUTF( env, "arg one" ); if( NULL == jArgOne ) { printf( "\nError: FAILED to create jArgOne." ); return ; } (*env)->SetObjectArrayElement( env, jObjArray, 0, jArgOne ); jArgTwo = (*env)->NewStringUTF( env, "arg two" ); if( NULL == jArgOne ) { printf( "\nError: FAILED to create jArgTwo." ); return ; } (*env)->SetObjectArrayElement( env, jObjArray, 1, jArgTwo ); jArgThree = (*env)->NewStringUTF( env, "arg three" ); if( NULL == jArgThree ) { printf( "\nError: FAILED to create jArgThree." ); return ; } (*env)->SetObjectArrayElement( env, jObjArray, 2, jArgThree ); printf( "SetObjectArrayElements\n" ); for( i = 0; i < 3; i++ ) { jStrVar = (*env)->GetObjectArrayElement( env, jObjArray, i ); printf( "\tAllocated value=> %s\n", (*env)->GetStringUTFChars( env, jStrVar, JNI_FALSE ) ); } (*env)->CallStaticVoidMethod( env, myClassInDll, MID_foo, jObjArray ); if( (*env)->ExceptionOccurred( env ) ) { (*env)->ExceptionDescribe( env ); } } void finalizeJavaRT (JavaVM* jvm) { (*jvm)->DestroyJavaVM (jvm); } int main() { HANDLE myDllHandle; JNIEnv *env; JavaVM *jvm; jclass myClassInDll; /* * First of all, load required component. * By the time of JET initialization, all components should be loaded. */ myDllHandle = loadDll (dllname); /* * Initialize JET run-time. * The handle of loaded component is used to retrieve Invocation API. */ initJavaRT (myDllHandle, &jvm, &env); /* * Look for class. */ myClassInDll = lookForClass(env, "MyClassInDll"); /* * Create an object and invoke instance method. */ invokeInstanceMethod(env, myClassInDll); /* * Invoke static method. */ invokeStaticMethod(env, myClassInDll); /* * Finalize JET run-time. */ finalizeJavaRT (jvm); return 0; }
  3. LaunchPad Fails on Linux

    I am running Fedora Core 4. Jet ran once, and I even built an image. But now it brings up a dialog saying: Cannot read JET version: Cannot Run: jc When I dismiss that, I get a new dialog saying: Cannot read JET configuration: java.lang.Exception : Cannot run jc = 0 In the background (command prompt), I see: waitpid failed: exit status 3
  4. HELP: Cannot run 'jetsetup' on Linux

    I am running Fedora Core 4 and getting exactly the same problem. Java 1.4.2.10 is installed, but not Java 1.5
  5. Hi, Well I purchased 3.6 and the Jet Pack Trial Run works as expected, but when I actually deploy it as an NT Service, it enters the running state, but then fails and is terminated unexpectedly with Service Control Manager ERROR 7034. Any ideas? TIA :-/
  6. I am going to purchase Jet, but I want to wait until Version 3.6 for Windows is out. Any idea when that will be? TIA
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