cocos2dx 3.1 报dvmFindClassByName rejecting 'Ljava.lang.String;'

借用网上char* 转jstring的函数时,在android平台运行后报上面的错误报错:

07-17 16:09:04.060: W/dalvikvm(7467): dvmFindClassByName rejecting 'Ljava.lang.String;'

07-17 16:09:04.060: A/libc(7467): Fatal signal 11 (SIGSEGV) at 0x0000002c (code=1)

原因是:

jclass strClass = (env)->FindClass(" Ljava/lang/String; ");这个在android里是找不到的

java中String的包名不是这个,而是 java/lang/String

底下两个函数都可以用于char* 转jstring:

jstring CStr2Jstring( JNIEnv* env, const char* pat )
 {
   //定义java String类 strClass
   jclass strClass = (env)->FindClass("java/lang/String");
   //获取java String类方法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, "", "([BLjava/lang/String;)V");
   //建立byte数组
   jbyteArray bytes = (env)->NewByteArray((jsize)strlen(pat));
   //将char* 转换为byte数组
   (env)->SetByteArrayRegion(bytes, 0, (jsize)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);
 }


 jstring chars2Jstring( JNIEnv* env, const char* pat )
 {
   //定义java String类 strClass
  JniMethodInfo class_init;
  //获取类的构造函数
        if (JniHelper::getMethodInfo(class_init,"java/lang/String","","([BLjava/lang/String;)V") == false)
        {
            CCLog("JniHelper::FindClass failed");
            return nullptr;
        }
   //建立byte数组 
   jbyteArray bytes = (env)->NewByteArray((jsize)strlen(pat));
   //将char* 转换为byte数组
   (env)->SetByteArrayRegion(bytes, 0, (jsize)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(class_init.classID, class_init.methodID, bytes, encoding);
 }

下面是jstring转char*的函数

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;
 }