testurldecoder.java

本书是一本为Java学习者在基础内容学习结束后进行课程设计时提供参考的指导书

package apibook.c5.s1;

import java.net.*;
import java.util.*;

//测试URLDecoder类
public class TestURLDecoder {
  public TestURLDecoder() {
  }
  public static void main(String[] args) {
    //创建新的入口
    Map m = new HashMap();
    m.put("com|163", "www.163.com");
    m.put("dst(p, q)", "sqrt((q.x-p.x)^2+(q.y-p.y)^2)");

    // 编码
    String data = encode(m);
    System.out.println(data);
    try {
        m = decode(data);
        System.out.println(m);
    } catch (Exception e) {
        e.printStackTrace();
    }
  }
  public static String encode(Map m) {
      int count = 0;
      StringBuffer buf = new StringBuffer();
      for (Iterator it=m.keySet().iterator(); it.hasNext(); count++) {
          String key = (String)it.next();

          if (count > 0) {
              buf.append('&');
          }
          buf.append(URLEncoder.encode(key)+"="+
              URLEncoder.encode((String)m.get(key)));
      }
      return new String(buf);
  }

  //编码字符串
  public static Map decode(String s) throws IllegalArgumentException {
      Map m = new HashMap();
      try {
          StringTokenizer st = new StringTokenizer(s, "&");

          while (st.hasMoreElements()) {
              s = (String)st.nextElement();
              String key = URLDecoder.decode(s.substring(0, s.indexOf('=')));
              String value = URLDecoder.decode(s.substring(s.indexOf('=')+1));
              m.put(key, value);
          }
      } catch (Exception e) {
          throw new IllegalArgumentException();
      }
      return m;
  }
}