How could java get two strings from c function?

Question

As title! I want to let a java code call C function. And the C funtion returns two unsigned char pointers.
Thanks a lot.

Answer 1

I have the other problem. When compile the code with jnienv, it always shows errors...It's because the code I posted is for C compiler, not C++.
Here is a complete example in C++.
Just compile the Java part, then the C++ part, then run it at the console:
java TestCStringIt should give you:
Hello
World!
// TestCString.java
class TestCString
    static
        System.loadLibrary("testcstring");
    native String[] getStrings();
    public static void main(String[] args)
        TestCString test = new TestCString();
        String[] strArray = test.getStrings();
        System.out.println(strArray[0]);
        System.out.println(strArray[1]);
// testcstring.h
#ifndef _Included_TestCString
#define _Included_TestCString
#include <jni.h>
#ifdef __cplusplus
extern "C" {
#endif
* Class:     TestCString
* Method:    getStrings
* Signature: ()[Ljava/lang/String;
JNIEXPORT jobjectArray JNICALL Java_TestCString_getStrings(JNIEnv * env, jobject obj);
#ifdef __cplusplus
#endif
#endif /* _Included_TestCString */
// testcstring.cpp
#include "testcstring.h"
static char * g1 = "Hello";
static char * g2 = "World!";
static void myCFunc(unsigned char ** pp1, unsigned char ** pp2)
    *pp1 = (unsigned char *)g1;
    *pp2 = (unsigned char *)g2;
* Class:     TestCString
* Method:    getStrings
* Signature: ()[Ljava/lang/String;
JNIEXPORT jobjectArray JNICALL Java_TestCString_getStrings(JNIEnv * env, jobject obj)
    unsigned char * p1;
    unsigned char * p2;
    jstring str1;
    jstring str2;
    jclass strCls;
    jobjectArray strArray;
    myCFunc(&p1, &p2); // call the c function
    str1 = env->NewStringUTF((const char *)p1); // create java string with first pointer
    str2 = env->NewStringUTF((const char *)p2); // create java string with second pointer
    strCls = env->FindClass("java/lang/String");
    strArray = env->NewObjectArray(2, strCls, NULL); // create java string array
    env->SetObjectArrayElement(strArray, 0, str1); // set first element
    env->SetObjectArrayElement(strArray, 1, str2); // set second element
    return strArray; // return java string array
}Regards