import java.io.UnsupportedEncodingException;

import java.util.Arrays;

/**

* ASCII-->GBK-->Unicode-->UTF-8

* 大小写英文字母、数字和一些符号-->增加中文-->所有类型文字，2个字节一个字符-->每种类型占用的字符个数自适应，减少了占用空间

*/

public class Encode {

public static void main(String[] args) throws UnsupportedEncodingException {

String s = "你好";

// 编码

byte[] utf = s.getBytes("utf-8");

byte[] gbk = s.getBytes("gbk");

System.out.println("utf-8编码：" + Arrays.toString(utf)); // [-28, -67, -96, -27, -91, -67] 6个字节

System.out.println("gbk编码：" + Arrays.toString(gbk)); // [-60, -29, -70, -61]<span style="white-space:pre"> </span>4个字节

// 解码

String s1 = new String(utf, "utf-8"); // 你好

String s2 = new String(utf, "gbk");// gbk解码：浣犲ソ gbk用2个字节解码，所以会多一个字符

String s3 = new String(gbk, "utf-8");// gbk用utf-8解码：??? <span style="white-space:pre"> </span>utf-8解码需要6个字节

System.out.println("--------------------");

System.out.println("utf-8解码：" + s1);

System.out.println("gbk解码：" + s2);

System.out.println("gbk用utf-8解码：" + s3);

System.out.println("---------------------");

System.out.println("用utf-8编码回去");

s3 = new String(s3.getBytes("utf-8"), "gbk"); // 锟斤拷锟? gbk用utf-8解码后无法编回去

System.out.println(s3);

}

}