Cannot instantiate java object from c funtion

Question

Hi guys,
I need some help on the following problem :
i want to call java method from c funtion using jni. My java method should instantiate another class on java side. Here's an example.
public class KMS {
    public int problemMethod() {
           System.out.println("We are in 1"); // This is written on the screen
           Parser parser = new Parser();
          System.out.println("We are in 2"); // This is not, but no problem on java side
         return 1;
public class Parser {
   // This class parse an XML document
}And Here's my c code :
void main(int argc, char *argv[])
     // create JVM with success
jclass cls =(jclass) env->NewGlobalRef (env->FindClass ("KMS"));
     if (cls == 0)
                          printf("cannot find cls \n");
     jmethodID mid = (env)->GetMethodID(cls, "<init>", "()V");
     if (mid == 0)
          printf("cannot find initialization\n");
     jobject jobj = (env)->NewObject(cls, mid);
     if (jobj == 0)
          printf("cannot find object\n");
     jmethodID mymid = (env)->GetMethodID(cls, "problemMethod", "()I");
     if(mymid == 0)
          printf("cannot find problemMethod\n");
     jint result = (env)->CallIntMethod(jobj, mymid);
     printf("result %d\n", result);
}I get the following when I run c program :
We are in 1
I get no error msg, and the return value is 0. It seems that the JVM cannot instantiate class Parser. But the problem is when I run java code only, from a java main, it works fine. Do I need to implement another things in c side in order to be able to instanciate class Parser.
Thanks a lot for your help,
javaFriendly

Answer 1

1. You have left out some important facts (like where
is your java code establishing the native method?
The native method and java codes can communicate. I can see the first System.out.println result when calling native method. My problem is for the second one. Class Parser cannot be instantiate. (But the java code is correct, I try it when I use only java).
2. Since your native code returns nothing, why would
you expect ANY particular value to be returned?
I was talking about return in java side. My java code should return me 1, but in native method a see a 0. This shows that there's an error when calling java.
3. I would not count on the printf statements. You
probably - sometime - should see some output, but if
you don't do a "flush" after ech one, then there is a
good chance it will not appear where you expect it.Can you tell me how to use "flush" in order to see all results,
Best regards
Java friendly