jstring return in JNI program

Question

This is JNI code.

Java code:

public class Sample1 {
 
    public native String stringMethod(String te         


        

Answer 1

this should be the way to do it....

JNIEXPORT jstring JNICALL Java_Sample1_stringMethod
    (JNIEnv *env, jobject obj, jstring string) 
{    
    const char *name = (*env)->GetStringUTFChars(env,string, NULL);
    char msg[60] = "Hello ";
    jstring result;
    
    strcat(msg, name);  
    (*env)->ReleaseStringUTFChars(env,string, name);   
    puts(msg);            
    result = (*env)->NewStringUTF(env,msg); 
    return result;        
}

Answer 2

There are several ways but the best I got by converting const char * to c++ string and then to jbyteArray, and its easy to conversion of byteArray to UTF-8 on java side.

C++ side:

const char* string = propertyValue;
std::string str = string;

jbyteArray array = env->NewByteArray(str.length());
env->SetByteArrayRegion(array,0,str.length(),(jbyte*)str.c_str());


return array;

Java/kotlin side:

String((array), Charset.defaultCharset()))