Jar包org.springframewrork.beans下org.springframework.beans.factory中BeanFactory类。BeanFactory为spring IOC的最基本的容器接口,其定义了对容器的一系列基本操作。如getBean(String name)返回容器中名name的bean。
IOC容器启动:
ContextLoaderListener继承ContextLoader类,实现ServletContextListener接口。ServletContextListener接口,它能够监听ServletContext对象的生命周期,实际上就是监听Web应用的生命周期。ContextLoaderListener就实现此监听接口,在contextInitialized方法中初始化应用容器,在contextDestroyed中关闭应用容器。ContextLoader类载入IOC容器作为根上下文存入ServletContext。此类主要包括对根上下文的初始化、关闭等相关操作。在创建WebApplicationContext时调用AbstractApplicationContext中的refresh()方法对WebApplicationContext进行初始化。
完成对ContextLoaderListener的初始化后,Tomcat会开始初始化DispatcherServlet。DispatcherServlet会建立自己的ApplicationContext,并以ServletContext中的根上下文作为自己的父上下文进行初始化,存入servletcontext中。其创建过程与创建根上下文类似。
DispatcherServlet继承FrameworkServlet继承HttpServletBean继承HttpSevlet,故此该类也为一个Servlet类。springweb首先将传统的httpservlet抽象类包装成了bean;frameworkservlet抽象出了web框架中的servlets的一些基本行为,比如对application context的访问;dispatcherservlet的主要工作就是将一个request分发到一个合适的处理器上,并将处理返回的modelandview绘制出来返回给客户端。FrameWorkServlet中的initServletBean调用DispatcherServlet中的onRefresh进行初始化,onRefresh调用initStrategies()方法对springMVC初始化HttpServletBean中的initServletBean()方法为空方法,其实现内容由其子类决定,此为templates的应用。(由具体类实现 ,子类可以改变实现内容,而不用修改操作流程。)
springmvc:
Spring的MVC框架主要由DispatcherServlet、处理器映射、处理器、视图解析器、视图组成。
整个处理过程从一个HTTP请求开始:
1)DispatcherServlet接收到请求后,根据对应配置文件中配置的处理器映射,找到对应的处理器映射项(HandlerMapping),根据配置的映射规则,找到对应的处理器(Handler)。
2)调用相应处理器中的处理方法,处理该请求,处理器处理结束后会将一个ModelAndView类型的数据传给DispatcherServlet,这其中包含了处理结果的视图和视图中要使用的数据。
3)DispatcherServlet根据得到的ModelAndView中的视图对象,找到一个合适的ViewResolver(视图解析器),根据视图解析器的配置,DispatcherServlet将视图要显示的数据传给对应的视图,最后给浏览器构造一个HTTP响应。
DispatcherServlet是整个Spring MVC的核心。它负责接收HTTP请求组织协调Spring MVC的各个组成部分。
@Controller
@RequestMapping("/login.action") public class LoginAction { //@RequestMapping(params= "method=validate",method=RequestMethod.POST) @RequestMapping(params = "method=validate") public String login(@ModelAttribute("userBean") UserBean userBean, HttpServletRequest request, HttpServletResponse response) { if(!"admin".equals(userBean.getName())){ return "index"; } if(!"123456".equals(userBean.getPassword())){ return "index"; } return "WEB-INF/view/main"; } @RequestMapping(params = "method=validate2") public String login2(@ModelAttribute("userBean") UserBean userBean, Model model) { if(!"admin".equals(userBean.getName())){ model.addAttribute("msg", "用户名错误");//加入属性及值到model中 return "index"; } if(!"123456".equals(userBean.getPassword())){ model.addAttribute("msg", "用户密码错误"); return "index"; } return "WEB-INF/view/main"; } @RequestMapping(params = "method=validate3") public ModelAndView login3(@ModelAttribute("userBean") UserBean userBean, HttpServletRequest request, HttpServletResponse response) { ModelAndView model = new ModelAndView(); model.addObject("userBean", userBean); if(!"admin".equals(userBean.getName())){ model.setViewName("index"); return model; } if(!"123456".equals(userBean.getPassword())){ model.setViewName("index"); return model; } model.setViewName("WEB-INF/view/main"); return model; } /**note: * import org.springframework.web.portlet.ModelAndView; * 不应该引入这个ModelAndView 应该引入: * import org.springframework.web.servlet.ModelAndView; * 否则跳转的路径将不正确 */ }
model
public class UserBean { private String name; private String password; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
applictionContext:
<?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.springmvc.action"/> <bean id="ViewResovler" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/" /> <property name="suffix" value=".jsp"></property> </bean> </beans>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <% 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 'index.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"> --> </head> <body> ${userBean.name} <form action="<%=basePath%>login.action?method=validate" method="post"> username:<input type="text" name="name"/><br/> password:<input type="text" name="password"/><br/> <input type="submit" value="ok"/> </form> ${msg} <form action="<%=basePath%>login.action?method=validate2" method="post"> username:<input type="text" name="name"/><br/> password:<input type="text" name="password"/><br/> <input type="submit" value="ok"/> </form> ${userBean.name} <form action="<%=basePath%>login.action?method=validate3" method="post"> username:<input type="text" name="name"/><br/> password:<input type="text" name="password"/><br/> <input type="submit" value="ok"/> </form> </body> </html>
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"> <servlet> <servlet-name>dipatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath*:applicationContext.xml</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>dipatcher</servlet-name> <url-pattern>*.action</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>