day09_request&response学习笔记

  1 package com.itheima.servlet;
  2 
  3 import java.beans.IntrospectionException;
  4 import java.beans.PropertyDescriptor;
  5 import java.io.IOException;
  6 import java.io.UnsupportedEncodingException;
  7 import java.lang.reflect.InvocationTargetException;
  8 import java.lang.reflect.Method;
  9 import java.util.Enumeration;
 10 import java.util.Map;
 11 
 12 import javax.servlet.ServletException;
 13 import javax.servlet.http.HttpServlet;
 14 import javax.servlet.http.HttpServletRequest;
 15 import javax.servlet.http.HttpServletResponse;
 16 
 17 import org.apache.commons.beanutils.BeanUtils;
 18 
 19 import com.itheima.entity.User;
 20 
 21 public class ServletDemo3 extends HttpServlet {
 22 
 23     public void doGet(HttpServletRequest request, HttpServletResponse response)
 24             throws ServletException, IOException {
 25         // 告诉服务器要使用什么码表，注：客户端浏览器使用的是什么码表，传过来给服务器的就该使用什么码表
 26         request.setCharacterEncoding("UTF-8"); // 注：只能处理post请求方式
 27 
 28         test1(request);
 29         test2(request);
 30         test3(request);
 31         test4(request);
 32     }
 33 
 34     private void test4(HttpServletRequest request) {
 35         try {
 36             User u = new User();
 37             System.out.println("封装数据前：" + u);
 38 
 39             BeanUtils.populate(u, request.getParameterMap());
 40 
 41             System.out.println("封装数据后：" + u);
 42         } catch (Exception e) {
 43             e.printStackTrace();
 44         }
 45     }
 46 
 47     private void test3(HttpServletRequest request) {
 48         try {
 49             User u = new User();
 50             System.out.println("封装数据前：" + u);
 51             // 获取表单数据
 52             Map<String, String[]> map = request.getParameterMap();
 53 
 54             for (Map.Entry<String, String[]> m : map.entrySet()) {
 55                 String name = m.getKey();
 56                 String[] value = m.getValue();
 57 
 58                 // 反射
 59                 // 创建一个属性描述器对象
 60                 PropertyDescriptor pd = new PropertyDescriptor(name, User.class);
 61                 // 得到setter属性对象
 62                 Method setter = pd.getWriteMethod();
 63 
 64                 if (value.length == 1) {
 65                     setter.invoke(u, value[0]); // 给只有一个值的变量赋值
 66                 } else {
 67                     setter.invoke(u, (Object) value); // 给复选框赋值
 68                 }
 69             }
 70 
 71             System.out.println("封装数据后：" + u);
 72             
 73         } catch (Exception e) {
 74             e.printStackTrace();
 75         }
 76     }
 77 
 78     private void test2(HttpServletRequest request) {
 79         // 获取表单提交的所有的name的名称
 80         Enumeration names = request.getParameterNames();
 81         while (names.hasMoreElements()) {
 82             String name = (String) names.nextElement(); // 得到每一个name名称
 83             String[] values = request.getParameterValues(name); // 根据name名称，得到value值
 84             for (int i = 0; values != null && i < values.length; i++) {
 85                 System.out.println(name + "\t" + values[i]);
 86             }
 87         }
 88     }
 89 
 90     private void test1(HttpServletRequest request) throws UnsupportedEncodingException {
 91         // 获取表单数据
 92         // 根据表单中name属性的名，获取value属性的值方法
 93         String username = request.getParameter("username");
 94         String pwd = request.getParameter("pwd");
 95         String sex = request.getParameter("sex");
 96         String[] hobbys = request.getParameterValues("hobby");
 97         String city = request.getParameter("city");
 98 
 99         // 解决get方式编码
100         username = new String(username.getBytes("iso-8859-1"), "UTF-8");
101         
102         System.out.println(username);
103         System.out.println(pwd);
104         System.out.println(sex);
105 
106         for (int i = 0; hobbys != null && i < hobbys.length; i++) {
107             System.out.print(hobbys[i] + "\t");
108         }
109         System.out.println();
110 
111         System.out.println(city);
112     }
113 
114     public void doPost(HttpServletRequest request, HttpServletResponse response)
115             throws ServletException, IOException {
116         doGet(request, response);
117     }
118 
119 }