jni java String 转C char*工具类

char* Jstring2CStr(JNIEnv*
env, jstring
jstr)
{
char* rtn =
NULL;
jclass clsstring =

(*env)->FindClass(env,"java/lang/String");
jstring strencode =
(*env)->NewStringUTF(env,"GB2312");
jmethodID mid =
(*env)->GetMethodID(env,clsstring,
"getBytes",
"(Ljava/lang/String;)[B");
jbyteArray barr=
(jbyteArray)(*env)->CallObjectMethod(env,jstr,mid,strencode); //
String .getByte("GB2312");
jsize alen =
(*env)->GetArrayLength(env,barr);
jbyte* ba =

(*env)->GetByteArrayElements(env,barr,JNI_FALSE);
if(alen > 0)
{
rtn =
(char*)malloc(alen+1);
//"\0"
memcpy(rtn,ba,alen);
rtn[alen]=0;
}
(*env)->ReleaseByteArrayElements(env,barr,ba,0);
//
return rtn;
}