字符码转换(一个小程序)

package test;


public class TestB {
 static String zhongwen = "中文";
 static byte[] bytes = null;

 public static void main(String[] args) throws Exception {
  // GBK
  //main1();
  // utf-8
  //main2();
  // GBK-->utf-8-->GBK
  //main3();
  // GBK-->iso8859-1-->utf-8-->iso8859-1-->GBK
  main4();

 }
 // GBK
 public static void main1() throws Exception {
  bytes = zhongwen.getBytes("GBK");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }
  System.out.println(new String(bytes, "GBK"));
 }
 // utf-8
 public static void main2() throws Exception {
  bytes = zhongwen.getBytes("utf-8");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }
  System.out.println(new String(bytes, "utf-8"));
 }
 // GBK-->utf-8-->GBK
 public static void main3() throws Exception {

  bytes = zhongwen.getBytes("GBK");
  System.out.println("--------GBK----------");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }

  bytes = zhongwen.getBytes("utf-8");
  byte [] bytes_copy = bytes;
  System.out.println("-------utf-8--------");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }

  //错误的组装方法
  System.out.println("-------error GBK--------");
  zhongwen = new String(bytes, "GBK");
  System.out.println(zhongwen);
  bytes = zhongwen.getBytes("GBK");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }
  //正确的组装方法
  System.out.println("-------GBK--------");
  System.out.println(new String(bytes_copy, "utf-8"));
 }
 // GBK-->iso8859-1-->utf-8-->iso8859-1-->GBK
 public static void main4() throws Exception {

  //最开始是GBK
  bytes = zhongwen.getBytes("GBK");
  System.out.println("--------GBK----------");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }

  //被组装成了iso8859-1,new出的字符串对象有问题,但是字节内容没变
  System.out.println("-------iso8859-1--------");
  zhongwen = new String(zhongwen.getBytes("GBK"), "iso8859-1");
  System.out.println(zhongwen);
  bytes = zhongwen.getBytes("iso8859-1");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }
  //转换成utf-8在网络上传输,一个byte转换为两个字节,所以一共8个字节
  bytes = zhongwen.getBytes("utf-8");
  System.out.println("-------utf-8--------");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }

  //server端接收到utf-8,首先组装成iso8859-1,new出的字符串对象有问题,显示4个问号
  System.out.println("-------server--iso8859-1------");
  zhongwen = new String(bytes, "utf-8");
  System.out.println(zhongwen);
  bytes = zhongwen.getBytes("iso8859-1");
  for (int i = 0; i < bytes.length; i++) {
   System.out.println(Integer.toHexString(bytes[i]));
  }

  //以iso8859-1得到字节,并组装成GBK
  System.out.println("-------GBK--------");
  System.out.println(new String(bytes, "GBK"));
 }



 public static void ____________________main() throws Exception {
  System.out.println(System.getProperty("file.encoding"));
  System.out.println(System.getProperty("user.language"));
  System.out.println(System.getProperty("user.region"));
 }

}

/*
--------GBK----------
ffffffd6
ffffffd0
ffffffce
ffffffc4
-------iso8859-1--------
????
ffffffd6
ffffffd0
ffffffce
ffffffc4
-------utf-8--------
ffffffc3
ffffff96
ffffffc3
ffffff90
ffffffc3
ffffff8e
ffffffc3
ffffff84
-------server--iso8859-1------
????
ffffffd6
ffffffd0
ffffffce
ffffffc4
-------GBK--------
中文
*/