Returning byte array in JNI

Question

Hi,
I am trying to return an array of byte from JNI to java. I read the tutorial but i still find it hard to understand.
BYTE *encoded is the variable that has the contents to be sent back to java.
jbytearray jb=encoded;
ret jb;
This does not seem to reurn anything!! Please help

Answer 1

This is the JNI implementation of the method:
public native byte[] returnArray (int size, byte initialValue).
JNIEXPORT jbyteArray JNICALL Java_Test_returnArray
  (JNIEnv *env, jobject This, jint size, jbyte initialValue) {
       //-- No error handling is being done...
       jbyte* buf = new jbyte[size];
       memset (buf, initialValue, size);
       jbyteArray ret = env->NewByteArray(size);
       env->SetByteArrayRegion (ret, 0, size, buf);
       delete[] buf;
       return ret;
}A jbyte is a signed char (a signed byte). You can mix signed bytes and unsigned bytes in C++ depending on your needs. This JNI method is the functional equivalent of the 100% Java function:
public byte[] returnArray (int size, byte initialValue) {
    byte[] ret = new byte[size];
    for (int i = 0; i < size; ++i) {
        ret[i] = initialValue;
    return ret;