SpringMVC几个核心类(控制器核心类,加载配置文件核心类,处理url影射核心类,处理视图资源核心类,方法动态调用核心类)
核心类
制器核心类:
•org.springframework.web.servlet.DispatcherServlet - 配置web.xml
加载配置文件核心类:
•org.springframework.web.context.ContextLoaderListener – spring的配置文件
处理url影射核心类:
•org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping-根据bean的名称请求一个bean. spring的配置文件- /abc
处理视图资源核心类:
•org.springframework.web.servlet.view.ResourceBundleViewResolver
•return hello – 决定返回的字符串由哪一个页面来显示。
•<context:component-scan package=“cn.hncu”/>用于替代上面的类。
方法动态调用核心类
•org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver
用Spring处理Web请求-Spring的MVC
DispatcherServlet是SpringMVC的核心类,它就是一个Servlet.此类默认读取WEB-INF/[servlet-name]-servlet.xml配置文件。
重要说明:DispatcherServlet可以多次配置到web.xml中,它们将会读取自己的配置文件,但不会共享Bean.如果希望设置一些共享的Bean应该配置ContextLoaderListener来读取Spring的配置文件。
canSpringmvc
web.xml
- <span style="color:#000000;"><?xml version="1.0" encoding="UTF-8"?>
- <web-app version="3.0"
- 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_3_0.xsd">
- <display-name></display-name>
- <!-- 架构一个Spring,需要配置一个监听器,配置文件位置及名称若想自己取,则需配置ContextConfigLocation参数 -->
- <context-param>
- <param-name>contextConfigLocation</param-name>
- <param-value>
- classpath:beans.xml
- </param-value>
- </context-param>
- <listener>
- <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
- </listener>
- <!-- 架SpringMVC还需再配一个DispatcherServlet -->
- <servlet>
- <servlet-name>hncu</servlet-name>
- <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
- <!-- 读取类似struts框架的配置文件struts.xml,该配置文件在springmvc的默认命名规则为:servlet的名字+" -servlet.xml "
- 如想自己制定springmvc的配置文件,则应进行以下配置:
- -->
- <init-param>
- <param-name>namespace</param-name>
- <param-value>hncu-servlet</param-value>
- </init-param>
- <!-- 项目一启动就加载SpringMVC的分发器 -->
- <load-on-startup>1</load-on-startup>
- </servlet>
- <servlet-mapping>
- <servlet-name>hncu</servlet-name>
- <url-pattern>/sp/*</url-pattern>
- </servlet-mapping>
- <welcome-file-list>
- <welcome-file>index.jsp</welcome-file>
- </welcome-file-list>
- </web-app>
- </span>
进入servlet后会读取配置文件hncu-servlet.xml
- <span style="color:#000000;"><?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:context="http://www.springframework.org/schema/context"
- xmlns:tx="http://www.springframework.org/schema/tx"
- xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
- http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
- http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.3.xsd">
- <!-- controller 的bean 可以用id或name标识,但id不能用"/",而name可以("/hello"标明访问路径) -->
- <bean name="/hello" class="cn.hncu.one.HelloWorldController"></bean>
- <!-- 为了把前段的url请求转换成访问对应的bean,要配如下这个类() spring4以后则可省略-->
- <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>
- <!-- 以转发形式显示的view必须配置下面这个的类以进行解析 -->
- <bean class="org.springframework.web.servlet.view.ResourceBundleViewResolver">
- <property name="basenames">
- <list>
- <value>hncu</value><!-- 资源配置文件在classpath下:hncu.properties -->
- </list>
- </property>
- <property name="defaultParentView" value="hncu"></property><!-- 配置默认父View -->
- </bean>
- <!-- 配置方法动态调用核心类 -->
- <bean id="MethodResolver" class="org.springframework.web.servlet.mvc.multiaction.ParameterMethodNameResolver">
- <!-- 默认执行的方法名 -->
- <property name="defaultMethodName" value="execute"></property>
- <property name="paramName" value="method"></property>
- </bean>
- <!-- 第2个Controller,演示多方法动态调用核心类 -->
- <bean name="/muliti" class="cn.hncu.one.MulitiMethodController">
- <property name="methodNameResolver" ref="MethodResolver"></property>
- </bean>
- </beans></span>
第一个controller-----HelloWorldController.java 访问方式:
- <span style="color:#000000;">package cn.hncu.one;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.web.servlet.ModelAndView;
- import org.springframework.web.servlet.View;
- import org.springframework.web.servlet.mvc.Controller;
- import org.springframework.web.servlet.view.RedirectView;
- //springmvc中的控制器要实现Controller接口,类似struts的action要实现Action接口一样
- public class HelloWorldController implements Controller{
- /* 版本1
- @Override
- public ModelAndView handleRequest(HttpServletRequest request,
- HttpServletResponse response) throws Exception {
- System.out.println("Hello Contorller......");
- return null;//没有导向结果页面
- }
- */
- /* 版本2导向一个重定向的结果页面
- @Override
- public ModelAndView handleRequest(HttpServletRequest request,
- HttpServletResponse response) throws Exception {
- System.out.println("Hello Contorller......RedirectView");
- //让控制器返回一个 重定向view
- View view=new RedirectView("/jsps/hello.jsp",true);//参数true表示访问时带项目名
- ModelAndView mv=new ModelAndView();//空参
- mv.setView(view);
- return mv;
- }
- */
- //版本3 导向一个转发的结果页面-----需要在配置文件中加载ResourceBundleViewResolver类
- @Override
- public ModelAndView handleRequest(HttpServletRequest request,
- HttpServletResponse response) throws Exception {
- System.out.println("Hello Contorller.....转发 ");
- //让我们的控制器返回一个 转发View
- ModelAndView mv=new ModelAndView("send","name","我的大城院");//导向 send 所对应的资源视图,并且封装参数:name="我的大城院"
- return mv;
- }
- }
- </span>
方法动态调用核心类需要一个properties的配置文件
- <span style="color:#000000;">hncu.(class)=org.springframework.web.servlet.view.JstlView
- hncu.url=/jsps/hello.jsp
- send.url=/jsps/one.jsp
- one.url=/jsps/one.jsp
- two.url=/jsps/two.jsp
- three.url=/jsps/three.jsp
- four.url=/jsps/four.jsp</span>
MulitiMethodController.java
- <span style="color:#000000;">package cn.hncu.one;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.web.servlet.ModelAndView;
- import org.springframework.web.servlet.mvc.multiaction.MultiActionController;
- import cn.hncu.domain.User;
- public class MulitiMethodController extends MultiActionController{
- //反模式:这种不带req和resp两个参数的方法不能被访问(要求至少要两个参数,多个也可以)
- public void one(){
- System.out.println("该方法访问不到.......");
- }
- public String execute(HttpServletRequest req,HttpServletResponse resp){
- System.out.println("这是一个默认方法,可以被访问到。。。。");
- return "one";
- }
- public String two(HttpServletRequest req,HttpServletResponse resp){
- System.out.println("two这个方法,可以被访问到。。。。");
- return "two";
- }
- public ModelAndView three(HttpServletRequest req,HttpServletResponse resp){
- System.out.println("three这个方法,可以被访问到。。。。");
- String name =req.getParameter("name");
- return new ModelAndView("three", "name", name);
- }
- //学习如何封装复杂数据
- public ModelAndView four(HttpServletRequest req,HttpServletResponse resp,User user){
- System.out.println("four这个方法,可以被访问到。。。。");
- ModelAndView mv=new ModelAndView();
- mv.setViewName("four");
- mv.addObject(user);
- return mv;
- }
- }
- </span>
方法名为"four"的访问路径为:http://localhost:8080/canSpringmvc/sp/muliti?method=four&name=Tom&age=21 Spring会帮我们封装对象
User.java值对象
- <span style="color:#000000;">package cn.hncu.domain;
- public class User {
- private String name;
- private Integer age;
- public String getName() {
- return name;
- }
- public void setName(String name) {
- this.name = name;
- }
- public Integer getAge() {
- return age;
- }
- public void setAge(Integer age) {
- this.age = age;
- }
- @Override
- public String toString() {
- return "User [name=" + name + ", age=" + age + "]";
- }
- }
- </span>