Java中编码问题

import java.io.UnsupportedEncodingException;


public class Test {

	private static String str="中国人";
	private static byte[] by=null;
	
	/**
	 * GBK
	 */
	public static void code(){
		try {
			by=str.getBytes("GBK");
			for(int i=0;i<by.length;i++){
				System.out.println(Integer.toHexString(by[i]));
			}
			System.out.println(new String(by,"GBK"));
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	/**
	 * UTF-8
	 */
	public static void code1(){
		try {
			by=str.getBytes("UTF-8");
			for(int i=0;i<by.length;i++){
				System.out.println(Integer.toHexString(by[i]));
			}
			System.out.println(new String(by,"UTF-8"));
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	/**
	 * GBK-->UTF-8-->GBK
	 */
	public static void code2(){
		try {
			by=str.getBytes("GBK");
			for(int i=0;i<by.length;i++){
				System.out.println(Integer.toHexString(by[i]));
			}
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
		try {
			by=str.getBytes("UTF-8");
			for(int i=0;i<by.length;i++){
				System.out.println(Integer.toHexString(by[i]));
			}
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
			}
	/**
	 * ISO8859-1
	 */
	public static void code3(){
		try {
			by=str.getBytes("ISO8859-1");
			for(int i=0;i<by.length;i++){
				System.out.println(Integer.toHexString(by[i]));
			}
		} catch (UnsupportedEncodingException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public static void main(String args[])throws Exception{
		code();
	}
}