cocos2dx：JniHelper

c++调用java

JniHelper
JniHelper

项目例子

void QNativeUtils::downloadApp(const char * appUrl, const char * version, const char * desc){
    JniMethodInfo t;
    if(JniHelper::getStaticMethodInfo(t, JAVA_CLASS, "downloadApp", "(Ljava/lang/String;Ljava/lang/String;Ljava/lang/String;)V"))
    {
        jstring jAppUrl = t.env->NewStringUTF(appUrl);
        jstring jVersion= t.env->NewStringUTF(version);
        jstring jDesc= t.env->NewStringUTF(desc);
        t.env->CallStaticVoidMethod(t.classID, t.methodID, jAppUrl, jVersion, jDesc);
        t.env->DeleteLocalRef(jAppUrl);
        t.env->DeleteLocalRef(jVersion);
        t.env->DeleteLocalRef(jDesc);
        t.env->DeleteLocalRef(t.classID);
    }
}

int QNativeUtils::getVersionCode(){
    JniMethodInfo t;
    if(JniHelper::getStaticMethodInfo(t, JAVA_CLASS, "getVersionCode", "()I"))
    {
        jint ret = t.env->CallStaticIntMethod(t.classID, t.methodID);
        t.env->DeleteLocalRef(t.classID);
        return ret;
    }
    return 0;
}

几个点：
1.string类型转换
c++转java

jstring jAppUrl = t.env->NewStringUTF(appUrl);

java转c++

std::string ret = JniHelper::jstring2string(str);

2.需手动释放的类型
引用类型，数组： jstring，jobject ，jobjectArray，jintArray ，jclass ，jmethodID

t.env->DeleteLocalRef(t.classID);

3.不要手动释放
基本类型： jint , jlong , jchar