Exception access violation using jlong instead of jint

Question

Hi,
I hope you can help me.
I'm using Java5 under Windows XP and I'm developing under Eclipse.
I try to use an "old" c-Application accesed via JNI.
Status Quo is that, I have access to the c-side, over my JNI-conform DLL. My current task is to translate the c-side structs to java-objects. This also works, but only with limitation.
Calling methods bidirectional is working, manipulation a java-object is like a walk on an warm and sunny Saturday afternoon.
But I'm not able to use all possible parameters (for now I have tried to use jobject, jstring, jint, jboolean, jlong).
The first problem I had, were using Strings as parameters, but this now I deal with the loopway over java/lang/object (using java/lang/String results in an access_violation).
The next problem, and the harder one, is, that I cannot use the type long or jlong.
int (jint) is no problem, with int all works fine, but if I change the environment, creating and using long, I allways get an the access_violation shown below.
Is there anything, I need to know?
working c-side-code:
jobject someObject;
jint anIntegerValue;
anIntegerValue =5;               
jmethodID mid3 = (*env)->GetMethodID(env, cl, "initReturnSomeObject", "(ILjava/lang/Object;)Ljava/lang/Object;");
               if(mid3 == (jmethodID)0) printf("\ndooofes MethodName4!\n");
                         else {
                              const char* myParams;
                              myParams = "ooooohwow!!!";
                              someObject = (*env)->CallObjectMethod(env, jobj, mid3,
                                         anIntegerValue, (*env)->NewStringUTF(env, myParams));
                         }wokring java-side-code
public Object initReturnSomeObject(int i, Object obj) {
          String s = (String)obj;
          System.out.println("String: "+s+"\nInteger: "+i);
          some = new SomeObject(s,i);
          if(some==null) System.out.println("Some is not yet initialized, FEAR!!!!\n");
          else System.out.println("Yoh, I'm soooo many good!! \nSome:\nString: "+some.getS1()+"\nInt: "+some.getI1()+"\n");
          return (Object)some;
so, und this code, doesn't work. you can see, the changes are dramatically!! ;)
sorry for my sarcasm. I do not know, why it doesn't work.
jlong aLongValue;
aLongValue = 2;
jmethodID mid3 = (*env)->GetMethodID(env, cl, "initReturnSomeObject", "(JLjava/lang/Object;)Ljava/lang/Object;");
               if(mid3 == (jmethodID)0) printf("\ndooofes MethodName4!\n");
                         else {
                              const char* myParams;
                                 myParams = "ooooohwow!!!";
                              someObject = (*env)->CallObjectMethod(env, jobj, mid3,
                                        aLongValue, (*env)->NewStringUTF(env, myParams));
     public Object initReturnSomeObject(long i, Object obj) {
          String s = (String)obj;
          System.out.println("String: "+s+"\nInteger: "+i+"\nLong: ");
          some = new SomeObject(s,(int)i);
          if(some==null) System.out.println("Some is not yet initialized, FEAR!!!!\n");
          else System.out.println("Yoh, I'm soooo many good!! \nSome:\nString: "+some.getS1()+"\nInt: "+some.getI1()+"\n");
          return (Object)some;
# An unexpected error has been detected by Java Runtime Environment:
#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d942975, pid=1784, tid=1648
# Java VM: Java HotSpot(TM) Client VM (1.6.0_03-b05 mixed mode, sharing)
# Problematic frame:
# V  [jvm.dll+0x182975]
# An error report file with more information is saved as hs_err_pid1784.log
# If you would like to submit a bug report, please visit:
#   http://java.sun.com/webapps/bugreport/crash.jsp
#do you need some other informations or details? something out of the log-file? ok, i have to take the bus, so sorry for uncomplete informations or sentences ;)
till later.

Answer 1

Hi,
I'm quite sure, the signature is correct. For failure check, yesterday I ran javap to check the signature, but I do also mean, that I changed the signature afterwards for several time. And, it works ;) at least the way, using Integer.
Trying to use java/lang/String everytime I got the Error, that the method could not be found - this is the part, I was wrong in my description. So the error-Message is a different one.
Belonging to the question for assumptions I made... it's difficult. I'm quite new to JNI, so, I don't know, what I can assume to do. The Method call seems to be a kind of reflection-mechanism. So I assume that the behaviour is similar. But reflection I'm not very firm, either ^^.
What I do assume is, that the parameter-value J fits to the java-type jlong. But a work around on this, I will try today. getting the jlong into an char* or using long instead of jlong or using Ljava/lang/Long; or a casted Long as Ljava/lang/Object; ...
I'm anxious to the ideas, I will have, bypassing this point. if there is no way, I will write a file, send a email or something like this ;)
Thx for thinking about my problem jschel!! It's great not to be alone.
John