SpringMVC_初级总结

最新推荐文章于 2022-10-04 18:19:47 发布

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本文详细介绍了SpringMVC的工作流程，从浏览器发起HTTP请求到服务器响应的全过程，包括DispatcherServlet的角色、Controller处理请求、ModelAndView数据封装及视图解析。并通过一个具体的示例项目，展示了SpringMVC配置文件、Controller实现、视图展示和Ajax交互的具体代码。

1.SpringMVC的工作原理

浏览器发出一个http请求给服务器，如果匹配DispatcherServlet的请求映射路径（在web.xml中指定），服务器将请求转交给DispatcherServlet.
DipatcherServlet接收到这个请求之后，根据请求的路径，将请求转交给相应的Controller
Controller处理后，返回ModelAndView对象（封装跳转页面，要传递的数据）
DispatcherServlet根据ViewResolver视图解析器，找到ModelAndView指定的JSP。（ModelAndView只是逻辑视图并不是一个正式的视图）
将JSP显示到浏览器中

2.代码

1.项目目录

2.ApplicationContext-mvc.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:mvc="http://www.springframework.org/schema/mvc"
    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.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc 
        http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
<!-- 如果显示找不到mvc:resources标签而报错的话,可能因为编辑器中的schema过于陈旧,这时将
http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd的结尾的3.0改成3.2即可 -->
    <!-- 要扫描的包 -->
    <context:component-scan base-package="org.jsoft.action."/>
	<!-- 启用注解和对对应目录下静态资源的访问 -->
	<mvc:annotation-driven/>	
	<mvc:resources mapping="/assets/**" location="/assets/"/>
	<!-- 视图解析器 -->
	<bean id="viewResolver"
        class="org.springframework.web.servlet.view.UrlBasedViewResolver">
    	<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
    	<property name="prefix" value="/"/>
    	<property name="suffix" value=".jsp"/>
	</bean>
</beans>

3.web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
	<!-- 配置springMVC的servlet -->
	<servlet>
		<servlet-name>springMvc</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<!-- 配置ApplicationContext.xml的路径 -->
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath:spring/ApplicationContext-mvc.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>springMvc</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>
</web-app>

4.vo类

public class Student {
	private Long id;
	private String name;
	private Integer age;
	/**getter and setter*/
}

5.C层StudentAction

import java.io.PrintWriter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.json.JSONObject;
import org.jsoft.vo.Student;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

@Controller
@RequestMapping("studentAction")
public class StudentAction {
	//方法一,返回的是一个字符串,根据视图解析器,会自动在前面加上/,在后面加上".jsp",在访问这个jsp页面
	@RequestMapping("/login")
	public String login(){
		System.out.println("StudentAction.login()");
		return "index";
	}
	//方法二,返回一个最常用的ModelAndView,里面可以添加要传向浏览器的数据和页面
	@RequestMapping("/register")
	public ModelAndView register(){
		Student student = new Student();
		student.setAge(50);
		student.setName("PinkFloyd");
		student.setId(1L);
		ModelAndView mv = new ModelAndView();
		mv.setViewName("register");//设置返回的页面
		mv.addObject("student", student);//添加键值对形式的返回数据
		mv.addObject("firstName", "David");
		mv.addObject("lastName", "Gilmour");
		return mv;
	}
	//方法三,需要接受页面数据时可以在方法的参数里添加request和response
	@RequestMapping("/update")//这是Ajax形式的请求
	public void update(HttpServletRequest request,HttpServletResponse response) throws Exception{
		request.setCharacterEncoding("UTF-8");
		response.setCharacterEncoding("UTF-8");
		Student student = new Student();
		String id = request.getParameter("id");
		String name = request.getParameter("name");
		String age = request.getParameter("age");
		student.setAge(new Integer(age));
		student.setName(name);
		student.setId(new Long(id));
		PrintWriter out = response.getWriter();
		out.print(JSONObject.fromObject(student).toString());//已json的形式返回
	}
}

6.V层register.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'register.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->
  <script type="text/javascript" src="assets/js/jquery-1.10.1.js"></script>

  </head>
  
  <body>
  
    Register.jsp <br/>
    Welcome!${student.id},${student.age},${student.name}乐队的
    
    <%=request.getAttribute("firstName") %>  ${lastName}
    
    <form id="f">
    	乐队id:<input name="id" value="${student.id}"/>
    	乐队年龄:<input name="age" value="${student.age}"/>
    	乐队名称:<input name="name" value="${student.name}"/>
    	<input id="btn" type="button" value="修改">
    </form>
    <script type="text/javascript" >
    $(function(){
    	$("#btn").click(function(){
    		$.ajax({
    			url:"studentAction/update",
    			type:"post",
    			data:$("#f").serialize(),
    			dataType:"json",
    			success : function(msg){
    				alert(msg.name);
    			}
    		})
    	})
    });
    </script>
  </body>
</html>