JNI中string和jstring转换

jstring str2jstring(JNIEnv* env,const char* pat){    //定义java String类 strClass    jclass strClass = (env)->FindClass("Ljava/lang/String;");    //获取String(byte[],String)的构造器,用于将本地byte[]数组转换为一个新String    jmethodID ctorID = (env)->GetMethodID(strClass, "<init>", "([BLjava/lang/String;)V");    //建立byte数组    jbyteArray bytes = (env)->NewByteArray(strlen(pat));    //将char* 转换为byte数组    (env)->SetByteArrayRegion(bytes, 0, strlen(pat), (jbyte*)pat);    // 设置String, 保存语言类型,用于byte数组转换至String时的参数    jstring encoding = (env)->NewStringUTF("GB2312");     //将byte数组转换为java String,并输出    return (jstring)(env)->NewObject(strClass, ctorID, bytes, encoding);}  std::string jstring2str(JNIEnv* env, jstring jstr){       char*   rtn   =   NULL;       jclass   clsstring   =   env->FindClass("java/lang/String");       jstring   strencode   =   env->NewStringUTF("GB2312");       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);       std::string stemp(rtn);    free(rtn);    return   stemp;   } 

// convert jbyteArray to std::string

jsize   alen   =   env->GetArrayLength(rawArray);    jbyte*   ba   =   env->GetByteArrayElements(rawArray,JNI_FALSE);    if(alen   >   0)    {        rtn   =   (char*)malloc(alen+1);        memcpy(rtn,ba,alen);        rtn[alen]=0;    }    env->ReleaseByteArrayElements(barr,ba,0);    std::string theStr(rtn);    free(rtn);

// convert jbyteArray to std::string

std:string native_strAddr = env->GetStringUTFChars(strAddr, NULL);

需要include<cstring>和<string>.