How to call Java method which returns String from C using JNI?

Question

Is there a way to call a java method, which returns a String in C?
For Integer it works like that:

JNIEXPORT jint JNICALL Java_Client_getAgeC(JNIEnv *env, jobject callingObject, jobject employeeObject) {
jclass employeeClass = (*env)->GetObjectClass(env, employeeObject);
jmethodID midGetAge = (*env)->GetMethodID(env, employeeClass, "getAge", "()I");
int age =  (*env)->CallIntMethod(env, employeeObject, midGetAge);
return age;
}

I've searched for a long time but nothing works for String. Finally, I want to get a char*
Thanks in advance!

Answer 1

Below is an example of JNI code calling a method returning a string. Hope this helps.

int EXT_REF Java_JNITest_CallJava(
    JNIEnv* i_pjenv, 
    jobject i_jobject
)
{
    jclass      jcSystem;
    jmethodID   jmidGetProperty;
    LPWSTR      wszPropName = L"java.version";

    jcSystem = i_pjenv->FindClass("java/lang/System");
    if(NULL == jcSystem)
    {
        return -1;
    }
    jmidGetProperty = i_pjenv->GetStaticMethodID(jcSystem,
                      "getProperty", "(Ljava/lang/String;)Ljava/lang/String;");
    if(NULL == jmidGetProperty)
    {
        return -1;
    }

    jstring joStringPropName = i_pjenv->NewString((const jchar*)wszPropName, wcslen(wszPropName));
    jstring joStringPropVal  = (jstring)i_pjenv->CallStaticObjectMethod(jcSystem, 
                               jmidGetProperty, (jstring)joStringPropName);
    const jchar* jcVal = i_pjenv->GetStringChars(joStringPropVal, JNI_FALSE);
    printf("%ws = %ws\n", wszPropName, jcVal);
    i_pjenv->ReleaseStringChars(joStringPropVal, jcVal);
    return 0;
}