request请求转换成对象。

1）前端post数据过来，key和val键值对会有不少，这个时候日后端进行插值的时候，最好将这些键值对转换成对象进行处理。

使用common-beanutils 来将前端传递过来的map直接转换成对象。

依赖jar包：

前端代码的name属性要和后端bean对象属性一致！

1   <h1>测试POST</h1>
2   <form action="/bean" method="post">
3     <input type="text" name="username">用户名字 4     <input type="password" name="passowrd">用户密码 5     <button type="submit">提交</button>
6   </form>
7   </body>
8 </html>

后端代码：

 1 package jd.com.bean_test;  2 
 3 import org.apache.commons.beanutils.BeanUtils;  4 
 5 import javax.servlet.ServletException;  6 import javax.servlet.annotation.WebServlet;  7 import javax.servlet.http.HttpServlet;  8 import javax.servlet.http.HttpServletRequest;  9 import javax.servlet.http.HttpServletResponse; 10 import java.io.IOException; 11 import java.util.Map; 12 
13 @WebServlet(name = "Servlet_Bean") 14 public class Servlet_Bean extends HttpServlet { 15     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 16         //只能针对post请求 不乱码。
17         request.setCharacterEncoding("utf-8"); 18         Map<String,String[]> data=request.getParameterMap(); 19         User user_obj=new User(); 20         try { 21  BeanUtils.populate(user_obj,data); 22         }catch (Exception ex){ 23  ex.printStackTrace(); 24             throw  new RuntimeException("转换出问题！"); 25  } 26         System.out.println(user_obj); 27 
28 
29  } 30 
31     protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 32 
33  } 34 }

 

 1 package jd.com.bean_test;  2 
 3 public class User {  4     private String username;  5     private String passowrd;  6     public User(){}  7 
 8     public void setUsername(String username) {  9         this.username = username; 10  } 11 
12     public void setPassowrd(String passowrd) { 13         this.passowrd = passowrd; 14  } 15 
16     public String getUsername() { 17         return username; 18  } 19 
20     public String getPassowrd() { 21         return passowrd; 22  } 23 
24  @Override 25     public String toString() { 26         return username+" "+passowrd; 27  } 28 }