java - 如何使用 jni 在 c 中替换 java 中的字符串数组的值？

Question

这是我的 jni 函数，我必须在其中替换从 java 传递的数组中的值。

请告诉我怎么做。

JNIEXPORT void JNICALL Java_com_example_finals_Strpass_intake
(JNIEnv *env, jobject obj, jobjectArray dev){

    jfieldID myNamesID; /* store the field ID */
    int i=0;
    jstring myStr;
    char* myStr2;
    char* myNames[] = {"Hello "};
    LOGI("before class call ");
    // Get a reference to obj’s class
    jclass cls = (*env)->GetObjectClass(env,obj);
    LOGI("before id call ");
    myNamesID = (*env)->GetStaticFieldID(env,cls, "myDevNames", "[Ljava/lang/String;");
    // Get the object field
    LOGI("before dev call ");
    dev =(*env)->GetStaticObjectField(env,cls,myNamesID);
    LOGI("before for loop call ");
    for (i=0; i<1; i++) {
        LOGI("before myStr ");
        myStr = (*env)->NewStringUTF(env,"gk");
        (*env)->SetObjectArrayElement(env,dev,i,myStr);
    }
    (*env)->ReleaseCharArrayElements(env, dev, myStr, 0);
    LOGI("after release");      
}

Answer 1

JNIEXPORT void JNICALL Java_com_example_contchar23914_CharArrClass_intake (JNIEnv *env, jobject 作业, jobjectArray ptr){

jclass cls = (*env)->GetObjectClass(env,job);

myNamesID = (*env)->GetStaticFieldID(env,cls, "arr", "[Ljava/lang/String;");

ptr =(*env)->GetStaticObjectField(env,cls,myNamesID);

for (i=0; i < len; i++) {

stringg = (*env)->GetObjectArrayElement(env, ptr,i);

    myStr = (*env)->NewStringUTF(env,myNames[i]);

    (*env)->SetObjectArrayElement(env,ptr,i,myStr);
}

    (*env)->ReleaseCharArrayElements(env, ptr, stringg, 0);