JNI jstring与c++字符串类型转换函数

jstring与c++字符串类型转换函数

 

jstring str2jstring(JNIEnv* env,const char* pat){//定义java String类 strClassjclass 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StringjmethodID 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; }