java中request常用方法小结(2)

package com.yyz.request;
 import java.io.IOException;
 import java.util.Enumeration;
 import java.util.Map;
 import java.util.Map.Entry;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 //获取请求数据
 public class RequestDemo extends HttpServlet {
   public void doGet(HttpServletRequest request, HttpServletResponse response)
       throws ServletException, IOException {
     //http://localhost:8080/test/servlet/RequestDemo?name=yyz
     String value = request.getParameter("name");
     System.out .println(value);
     //http://localhost:8080/test/servlet/RequestDemo?like=sing&like=dance
     String likes[] = request.getParameterValues("like");
     if(likes!=null){
       for(String like : likes){
         System.out.println(like);
       }
     }
     //下面是这种遍历的专业写法,获取数组数据的方式（可避免空指针异常）
     for(int i=0;likes!=null&&i<likes.length;i++){
       System.out.println(likes[i]);
     }
     //获取所有名称，并根据名称获取值
     Enumeration e = request.getParameterNames();
     while(e.hasMoreElements()){
       String name = (String) e.nextElement();
       value = request.getParameter(name);
       System.out.println(name+"="+value);
     }
     System.out.println("----------------------");
     //得到request对象中用来封装数据的Map集合
     Map<String,String[]> map = request.getParameterMap();
     for(Entry<String, String[]> me : map.entrySet()){
       String name = me.getKey();
       String [] v = me.getValue();
       System.out.println(name+"="+v[0]);
     }
 } 
   public void doPost(HttpServletRequest request, HttpServletResponse response)
       throws ServletException, IOException {
     doGet(request,response);
 }
 }