Jni C 与 Java 互调

 

1.头文件

#include <jni.h>
#include "platform/android/jni/JniHelper.h"
#include <android/log.h>

2. jstring 与 char * 的转换

char* jstringTostring(JNIEnv* env, jstring jstr)
    {
        char* rtn = NULL;
        jclass clsstring = env->FindClass("java/lang/String");
        jstring strencode = env->NewStringUTF("utf-8");
        jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
        jbyteArray barr= (jbyteArray)env->CallObjectMethod(jstr, mid, strencode);
        jsize alen = env->GetArrayLength(barr);
        jbyte* ba = env->GetByteArrayElements(barr, JNI_FALSE);
        if (alen > 0)
        {
            rtn = (char*)malloc(alen + 1);
            memcpy(rtn, ba, alen);
            rtn[alen] = 0;
        }
        env->ReleaseByteArrayElements(barr, ba, 0);
        return rtn;
    }

3.1 Java  - 调用- C（C代码）

jint Java_com_elextech_ccgoe_GooglePay_nativePayOK(JNIEnv *env, jobject thiz, jint a, jstring b)
    {
        CCLOG("********** nativePayOK*******");
        Pay_ID = a;
        if(Pay_ID==0){
            CCLOG("Error in pay");
            return -1;
        }

        char * re ;
        re = jstringTostring(env , b);
        sprintf(Pay_Check,"%s",re);

        CCLOG("*****Pay_id****%d",Pay_ID);
        CCLOG("Pay_Check :%s",Pay_Check);

        GameBoard::sharedGameBoard()->paymentAddPoints(Pay_ID,"",Pay_Check);

        return 1;
    }

3.2 Java  - 调用- C（java代码）

private native int nativePayOK(int a , String b);

public void onSuccessPay_byProductId(Order order) {
                int productId = Integer.parseInt(order.getProductId());
                Log.i("jnitest", "------nativePayOK---order.getProductId():"+productId);

                nativePayOK(productId, order.getOrderId());
            }

4.1  C - 调用- Java （java代码）

public static void Click_pay(int pay_id){
         Log.i("jnitest", "------------goolge pay---pay_id:"+pay_id);
 payItem.setItemType(PayItemData.ITEM_TYPE_INAPP);
         payItem.setItemId(""+pay_id);
    GamePayImpl.getInstance().onSubmitPayAction(payItem);

}

4.2  C - 调用- Java （C代码）

#if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID)
    JniMethodInfo minfo;
bool isHave;
if (gameBoardViewDelegate->if_QQLogin())
{
    CCLOG("qq pay");
    isHave = JniHelper::getStaticMethodInfo(minfo,  "com/elextech/goeqq/QQActivity","Click_qq_pay","(I)V");
}
else
{
    CCLOG("google pay ");
    isHave = JniHelper::getStaticMethodInfo(minfo,  "com/elextech/ccgoe/GooglePay","Click_pay","(I)V");
}

    jobject jobj;
    if (!isHave) {
        CCLOG("jni: no method");
    }

    jobj = minfo.env->CallStaticObjectMethod(minfo.classID, minfo.methodID,pay_id);

    CCLOG("jni-java over");

    #endif

 4.3 C传jstring给java

JniMethodInfo minfo;
if (! JniHelper::getStaticMethodInfo(minfo, "com/elextech/goelib/GOE", "umeng_event", "(Ljava/lang/String;)V") ) {
    CCLOG("jni: no method");
    return;
}

jstring jevent=minfo.env->NewStringUTF(event);
minfo.env->CallStaticVoidMethod(minfo.classID, minfo.methodID, jevent);
minfo.env->DeleteLocalRef(jevent);

 5. Java 传byte[]在C中的转换

jint Java_com_elextech_goeqq_QQActivity_netiveQQLoginOK(JNIEnv *env, jobject thiz, jstring a, jbyteArray b)

jbyte * olddata = (jbyte*)env->GetByteArrayElements(b, 0);
jsize  oldsize = env->GetArrayLength(b);
unsigned char* bytearr = (unsigned char*)olddata;
int len = (int)oldsize;