从URLDecoder.java复制

//package com.nowjava;
/* from nowjava.com*/

import java.io.UnsupportedEncodingException;


public class Main {

    public static void main(String[] argv) throws Exception {

        String s = "nowjava.com";

        System.out.println(decode(s));

    }


    /**

     * Copied from URLDecoder.java

     */

    public static String decode(String s) {

        StringBuffer sb = new StringBuffer();

        for (int i = 0; i < s.length(); i++) {

            char c = s.charAt(i);

            switch (c) {

            case '+':

                sb.append(' ');

                break;
                /**来自 
                 nowjava.com - 时代Java**/

            case '%':

                try {

                    sb.append((char) Integer.parseInt(

                            s.substring(i + 1, i + 3), 16));

                } catch (NumberFormatException e) {

                    throw new IllegalArgumentException(s);

                }

                i += 2;

                break;

            default:

                sb.append(c);

                break;

            }

        }

        // Undo conversion to external encoding

        String result = sb.toString();

        try {