菜鳥學習Spring——SpringMVC註解版前臺向後臺傳值的兩種方式

一、概述。

在很多企業的開法中常常用到SpringMVC+Spring+Hibernate（mybatis）這樣的架構，SpringMVC相當於Struts是頁面到Contorller直接的交互的框架也是界面把信息傳輸到Contorller層的一種架構，通過這個架構可以讓我們把頁面和Contorller層解耦，使得開發人員的分工更加明確。

二、代碼演示。

1、首先配置SpringMVC環境。

1.1導入jar。

值得注意的是紅色標記的commons-logging這個jar包一定得引入進去不然會報錯。

1.2、xml配置文件。

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">
		<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>

springMVC-servlet.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	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">
	<context:component-scan base-package="com.gaowei.controller" />
</beans>

2、前臺界面代碼。

<%@ 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="login.spring" method="post">
	username:<input type="text" name="username">
	<br/>
	password:<input type="text" name="password">
	<br/>
	<input type="submit" value="登錄">
</form>
</body>
</html>

No.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>
No!
</body>
</html>

Ok.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>
 OK！ welcome:${username}
</body>
</html>

3、Contorller層接收前臺的兩種方式。

方式一：

利用@RequestParam這個註解

	package com.gaowei.controller;
	
	import org.springframework.stereotype.Controller;
	import org.springframework.ui.Model;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RequestParam;
	
	@Controller
	public class Login {
	
		//方式一
		@RequestMapping("/login")
		public String login(@RequestParam("username") String username,
							@RequestParam("password") String password,Model model){
			if (username.equals(password)) 
			{
				model.addAttribute("username", username);
				return "ok.jsp";
			} else {
				return "no.jsp";
			}
		}
	}

方式二：

	package com.gaowei.controller;
	
	import org.springframework.stereotype.Controller;
	import org.springframework.ui.Model;
	import org.springframework.web.bind.annotation.RequestMapping;
	import org.springframework.web.bind.annotation.RequestParam;
	
	@Controller
	public class Login {
	@RequestMapping("/login")
		public String login(String username,String password,Model model){
			if (username.equals(password)) 
			{
				model.addAttribute("username", username);
				return "ok.jsp";
			} else {
				return "no.jsp";
			}
		}
	
	}