/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class com_haohao_hellojni_NativeTest */
#ifndef _Included_com_haohao_hellojni_NativeTest
#define _Included_com_haohao_hellojni_NativeTest
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     com_haohao_hellojni_NativeTest
 * Method:    getString
 * Signature: ()Ljava/lang/String;
 */
JNIEXPORT jstring JNICALL Java_com_haohao_hellojni_NativeTest_getString__
  (JNIEnv *, jobject);
/*
 * Class:     com_haohao_hellojni_NativeTest
 * Method:    getString
 * Signature: (Ljava/lang/String;)Ljava/lang/String;
 */
JNIEXPORT jstring JNICALL Java_com_haohao_hellojni_NativeTest_getString__Ljava_lang_String_2
  (JNIEnv *, jobject, jstring);
/*
 * Class:     com_haohao_hellojni_NativeTest
 * Method:    getInt
 * Signature: ()I
 */
JNIEXPORT jint JNICALL Java_com_haohao_hellojni_NativeTest_getInt__
  (JNIEnv *, jobject);
/*
 * Class:     com_haohao_hellojni_NativeTest
 * Method:    getInt
 * Signature: (I)I
 */
JNIEXPORT jint JNICALL Java_com_haohao_hellojni_NativeTest_getInt__I
  (JNIEnv *, jobject, jint);
/*
 * Class:     com_haohao_hellojni_NativeTest
 * Method:    input
 * Signature: (Ljava/lang/String;I)V
 */
JNIEXPORT void JNICALL Java_com_haohao_hellojni_NativeTest_input__Ljava_lang_String_2I
  (JNIEnv *, jobject, jstring, jint);
/*
 * Class:     com_haohao_hellojni_NativeTest
 * Method:    input
 * Signature: ([Ljava/lang/String;I)V
 */
JNIEXPORT void JNICALL Java_com_haohao_hellojni_NativeTest_input___3Ljava_lang_String_2I
  (JNIEnv *, jobject, jobjectArray, jint);
/*
 * Class:     com_haohao_hellojni_NativeTest
 * Method:    getBytes
 * Signature: ([Ljava/lang/String;Ljava/lang/String;)[B
 */
JNIEXPORT jbyteArray JNICALL Java_com_haohao_hellojni_NativeTest_getBytes
  (JNIEnv *, jobject, jobjectArray, jstring);
#ifdef __cplusplus
}
#endif
#endif

package com.haohao.hellojni;
import android.util.Log;
/**
 * author: haohao
 * time: 2018/1/1
 * mail: haohaochang86@gmail.com
 * desc: description
 */
public class NativeUtils {
    static {
        System.loadLibrary("native-utils");
    }
    private static final String TAG = "NativeUtils";
    public static int staticProp = -1;
    public int prop = -1;
    public String getStringFromJava(String str){
        Log.i(TAG, "getStringFromJava: "+ str);
        return "Hello C , I am from Java.";
    }
    public static String getStringFromJavaStatic(String str){
        Log.i(TAG, "getStringFromJavaStatic: " + str);
        return "Hello C , I am from Java static.";
    }
    public native void accessJavaClassProp();
    public native void callJavaClassMethod();
    public static native void accessStaticJavaProp();
    public static native void callStaticJavaMethod();
}

JNIEXPORT void JNICALL
Java_com_haohao_hellojni_NativeUtils_accessJavaClassProp(JNIEnv *env, jobject instance) {
    //访问 Java 对象的非静态属性
    //通过 JNIEnv 和对象 instance 实例拿到 class 。
    jclass cls = (*env)->GetObjectClass(env, instance);
    //获取属性的 field id
    jfieldID fid = (*env)->GetFieldID(env, cls, "prop", "I");
    //通过 field id 获取属性的值
    jint prop = (*env)->GetIntField(env, instance, fid);
    //在 Native 层修改属性
    prop += 101;
    (*env)->SetIntField(env, instance, fid, prop);
}

JNIEXPORT void JNICALL
Java_com_haohao_hellojni_NativeUtils_callJavaClassMethod(JNIEnv *env, jobject instance) {
    //调用 Java 对象的非静态方法
    jclass myClass = (*env)->GetObjectClass(env, instance);
    //获取发方法的 method id
    jmethodID mid = (*env)->GetMethodID(env, myClass, "getStringFromJava", "(Ljava/lang/String;)Ljava/lang/String;");
    //调用 Java 对象的方法
    jstring  jstr = (*env)->CallObjectMethod(env, instance, mid, (*env)->NewStringUTF(env, "Hello Java, I am From C."));
    //jstring 转换为 c 的字符串
    const char* cstr = (*env)->GetStringUTFChars(env, jstr, NULL);
    LOGD("%s", cstr);
    //注意区别对待 Java 字符串和 C 的字符串，除了基本数据类型之外，其他都需要进行类型转换
    //释放资源
    (*env)->ReleaseStringUTFChars(env, jstr, cstr);
}

JNIEXPORT void JNICALL
Java_com_haohao_hellojni_NativeUtils_accessStaticJavaProp(JNIEnv *env, jclass type) {
    //访问 Java 对象的静态属性,
    jfieldID fid = (*env)->GetStaticFieldID(env, type, "staticProp", "I");
    jint staticProp = (*env)->GetStaticIntField(env, type, fid);
    staticProp += 101;
    (*env)->SetStaticIntField(env, type, fid, staticProp);
}

JNIEXPORT void JNICALL
Java_com_haohao_hellojni_NativeUtils_callStaticJavaMethod(JNIEnv *env, jclass type) {
    //调用 Java 对象的静态方法
    jmethodID mid = (*env)->GetStaticMethodID(env, type, "getStringFromJavaStatic", "(Ljava/lang/String;)Ljava/lang/String;");
    jstring jstr = (*env)->CallStaticObjectMethod(env, type, mid, (*env)->NewStringUTF(env, "Hello Java, I am From C."));
    const char* cstr = (*env)->GetStringUTFChars(env, jstr, NULL);
    LOGD("%s", cstr);
    //释放资源
    (*env)->ReleaseStringUTFChars(env, jstr, cstr);
}

nativeUtils = new NativeUtils();
Log.i(TAG, "old prop : " + nativeUtils.prop);
nativeUtils.accessJavaClassProp();
Log.i(TAG, "new prop : " + nativeUtils.prop);
Log.i(TAG, "old static prop : " + NativeUtils.staticProp);
NativeUtils.accessStaticJavaProp();
Log.i(TAG, "new static prop : " + NativeUtils.staticProp);
nativeUtils.callJavaClassMethod();
NativeUtils.callStaticJavaMethod();

I/MainActivity: old prop : -1
I/MainActivity: new prop : 100
I/MainActivity: old static prop : -1
I/MainActivity: new static prop : 100
I/NativeUtils: getStringFromJava: Hello Java, I am From C.
I/native-utils: Hello C , I am from Java.
I/NativeUtils: getStringFromJavaStatic: Hello Java, I am From C.
I/native-utils: Hello C , I am from Java static.