菜鳥學習Spring——SpringMVC注解版將URL中的參數轉成實體 · 菜鳥學SSH

## 一、概述將URL中參數轉成實體在我們項目中用的很多比如界面提交表單請求后臺的Contorller的時候通過URL傳遞了一串參數到后臺，后臺通過Spring讓界面的字段與實體的字段映射來實現給后臺的實體屬性賦值。 ## 二、代碼演示。 2.1 web.xml ~~~ <?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"> <filter> <filter-name>encodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> </filter> <filter-mapping> <filter-name>encodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>springMVC</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springMVC</servlet-name> <url-pattern>*.spring</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app> ~~~ 2.2springMVC-servlet.xml ~~~ <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd"> <context:component-scan base-package="com.gaowei.ParamToObject" /> </beans> ~~~ 2.3test.jsp ~~~ <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <form action="paramToEntity.spring" method="POST"> username: <input type="text" name="username"> <br/> password: <input type="text" name="password"> <br/> <input type="submit" name="submit"> <br/> </form> </body> </html> ~~~ 2.4后臺代碼。 ![](https://box.kancloud.cn/2016-02-22_56caddfce0b08.jpg) Userinfo.java ~~~ package com.gaowei.entity; public class Userinfo { private String username; private String password; public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } } ~~~ ParamToEntity.java ~~~ package com.gaowei.ParamToObject; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import com.gaowei.entity.Userinfo; @Controller public class ParamToEntity { @RequestMapping(value="paramToEntity",method=RequestMethod.POST) public String paramToEntity(Userinfo userinfo){ System.out.println("username value="+userinfo.getUsername()); System.out.println("password value="+userinfo.getPassword()); return "test.jsp"; } } ~~~ 2.5效果圖。 ![](https://box.kancloud.cn/2016-02-22_56caddfcf1212.jpg) ![](https://box.kancloud.cn/2016-02-22_56caddfd0b82b.jpg) ## 三、總結。前臺向后臺傳遞數據有很多種方式，我們可以根據不同的情況用不同的方法這也讓我意識到以后我們要開發框架的時候要給使用者提供很多不同的方式來對應不同的情況。