JNI解决字符串乱码问题

• 定义java测试类

package com.example;

public class StringDeal {
    
    public native static String resolveString(String str);
    
    static{
        System.loadLibrary("StringDeal");
    }
    public static void main(String[] args) {
        System.out.println(resolveString(""));
    }

}

• 实现c代码

/*
* Class:     com_example_StringDeal
* Method:    resolveString
* Signature: (Ljava/lang/String;)V
*/
JNIEXPORT jstring JNICALL Java_com_example_StringDeal_resolveString
(JNIEnv *env, jclass jcls, jstring jstr){
    char *c_str = "我是来自c的字符串,现在要返回给java端使用";
    printf("%s \n", c_str);
    //查找class
    jclass jclz = (*env)->FindClass(env, "java/lang/String");
    if (jclz == NULL)
    {
        return NULL;
    }
    //获取构造函数
    jmethodID jmid = (*env)->GetMethodID(env, jclz, "<init>", "([BLjava/lang/String;)V");
    if (jmid == NULL)
    {
        return NULL;
    }
    //获取字符串长度
    jsize size = strlen(c_str);
    //构建一个新的jbyteArray
    jbyteArray jbytes =(*env)->NewByteArray(env, size);
    //将c_str的值赋给jbytes
    (*env)->SetByteArrayRegion(env, jbytes, 0, size, c_str);
    //构建字符编码
    jstring js = (*env)->NewStringUTF(env, "GB2312");
    //创建一个String对象 通过构造函数String(byte [] bytes ,String charset);
    return (*env)->NewObject(env, jclz, jmid, jbytes, js);;

}

运行结果.png