spring mvc基础 - 小小程序员J211

Spring mvc

1. 创建Web工程，导入Spring Web MVC相关开发包。

Spring API、web、webmvc等开发包。

2. 在src下添加Spring Web MVC的XML配置文件。

名称可以自定义，例如spring-mvc.xml。

3. 在web.xml中配置DispatcherServlet前端控制器组件。

DispatcherServlet组件在spring mvc中已提供，只需要配置即可。
配置DispatcherServlet时，同时指定XML配置文件。

<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>

11.</servlet>

12.<servlet-mapping>

<servlet-name>springmvc</servlet-name>
<url-pattern>*.form</url-pattern>

15.</servlet-mapping>

4.配置HandlerMapping组件，通过HandlerMapping组件，DispatcherServlet控制器可以将客户HTTP请求映射到Controller组件上。

使用如下配置可以实现当客户发出hello.form请求时，会调用HelloController组件进行处理。具体的代码如下:

<bean class="org.springframework.web.servlet.handler.
SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/hello.form“>helloController</prop>
</props>
</property>
</bean>

5．编写Controller组件，它负责执行具体的业务处理，可调用DAO等组件，编写时需要实现Controller接口及约定方法

public class HelloController implements Controller {
public ModelAndView handleRequest(
HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out.println("接受到请求");
return new ModelAndView("hello");
}
}

Controller组件约定的handleRequest方法执行后返回一个ModelAndView对象，该对象可封装模型数据和视图名响应信息。

并且将HelloController配置到spring-mvc.xml, 代码如下:

<bean id="helloController"
class="org.tarena.web.HelloController"/>

6. 配置视图解析器ViewResolver。所有Controller组件都返回一个ModelAndView实例，封装了视图名。 Spring中的视图以名字为标识，视图解析器ViewResolver通过名字来解析视图。 InternalResourceViewResolver使用示例代码如下：

<bean id="jspViewResolver"
class="org.springframework.web.servlet.view.
InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>

导包：

spring基础包

Spring-core-3.2.8.RELEASE.jar

Spring-context-3.2.8.RELEASE.jar

Spring-bean-3.2.8.RELEASE.jar

Commons-logging.jar

Spring-expression-3.2.8.RELEASE.jar

spring mvc基础包

Spring-web-3.2.8.RELEASE.jar

Spring-webmvc-3.2.8.RELEASE.jar

步骤二：配置Spring HandlerMapping 组件

1. Spring HandlerMapping用于分发Web请求到Controller的映射，这个类来自Spring MVC API，只需要配置到Spring中即可。修改spring-mvc.xml添加HandlerMapping配置。配置代码如下：

<bean id="handlerMapping"
class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings" ref="urlMappings"/>
</bean>
<util:properties id="urlMappings">
　　<prop key="/hello.form">helloController</prop>
<prop key="/***">***Controller</prop>
</util:properties>

<bean id="handlerMapping"

class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">

</bean>

<util:properties id="urlMappings">

<prop key="/hello.form">helloController</prop>

</util:properties>

其中HandlerMapping实现类是Spring提供的SimpleUrlHandlerMapping。SimpleUrlHandlerMapping的mappings属性引用了id为urlMappings的Properties集合。

步骤四：添加ViewResolver组件配置

1. 在spring-mvc.xml文件中增加ViewResolver组件的配置，ViewResolver用于视图的显示结果处理。代码如下所示：

<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>

由图-7可以说明Spring MVC HelloWorld开发部署测试成功，请求执行流程是：

1. 浏览器向Tomcat6服务器发起Web请求“hello.form”。

2. Tomcat6 会根据web.xml的配置将 “hello.form”请求交给Spring核心控制器DispatcherServlet处理。

3. DispatcherServlet根据HandlerMapping中的urlMappings将"/hello.form"请求转给helloController处理。

4. helloController执行handlerRequest()方法，处理请求，并且返回ModelAndView对象代表处理结果, ModelAndView对象中包含了目标视图“hello”。

5. Spring核心控制器收到ModelAndView中包含的视图“hello”。

6. Spring核心控制器利用ViewResolver中的前后缀应用“hello”到/WEB-INF/jsp/hello.jsp文件。

7. 执行hello.jsp 作为响应结果发送到浏览器。

8. 浏览器收到hello.jsp的执行结果：欢迎进入Spring Web MVC世界!

HelloController类的完整代码

package com.tarena.controller;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

11.import org.springframework.web.servlet.ModelAndView;

13.import org.springframework.web.servlet.mvc.Controller;

17.public class HelloController implements Controller{

public ModelAndView handleRequest(
HttpServletRequest req,
HttpServletResponse res) throws Exception {
System.out.println("处理hello.form请求");
ModelAndView mv = new ModelAndView("hello");
return mv;//调用hello.jsp
}

35.}

TestCase累的完整代码

package com.tarena.test;
import java.util.Properties;
import org.junit.Test;

11.import org.springframework.context.ApplicationContext;

13.import org.springframework.context.support.ClassPathXmlApplicationContext;

15.import org.springframework.web.servlet.HandlerMapping;

17.import org.springframework.web.servlet.ViewResolver;

19.import org.springframework.web.servlet.mvc.Controller;

23.public class TestCase {

/** HandlerMapping 映射测试 */
@Test
public void testHandlerMapping(){
String cfg = "spring-mvc.xml";
ApplicationContext ac = new ClassPathXmlApplicationContext(cfg);
HandlerMapping obj = ac.getBean("handlerMapping", HandlerMapping.class);
Properties map = ac.getBean("urlMappings", Properties.class);
System.out.println(obj);
System.out.println(map);
}
/** 控制器测试 */
@Test
public void testHelloController(){
String cfg = "spring-mvc.xml";
ApplicationContext ac = new ClassPathXmlApplicationContext(cfg);
Controller obj = ac.getBean("helloController", Controller.class);
System.out.println(obj);
}
/** 测试ViewResolver配置 */
@Test
public void testViewResolver(){
String cfg = "spring-mvc.xml";
ApplicationContext ac = new ClassPathXmlApplicationContext(cfg);
ViewResolver obj = ac.getBean("viewResolver", ViewResolver.class);
System.out.println("OK"+obj);
}

74.}

Spring-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:context="http://www.springframework.org/schema/context"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jee="http://www.springframework.org/schema/jee"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd" >
<bean id="handlerMapping"
class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings" ref="urlMappings" />
</bean>
<util:properties id="urlMappings">
<prop key="/hello.form">helloController</prop>
</util:properties>
<bean id="helloController"
class="com.tarena.controller.HelloController" />
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>

74.</beans>

Hello.jsp

<%@page pageEncoding="utf-8" contentType="text/html;charset=utf-8"%>
<!DOCTYPE html>
<html>
<head>
<title>Spring Hello World!</title>
</head>
<body>
欢迎进入Spring Web MVC世界!
</body>

13.</html>

Web.xml文件

<?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>springmvc</servlet-name>
<servlet-class>
org.springframework.web.servlet.DispatcherServlet
</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springmvc</servlet-name>
<url-pattern>*.form</url-pattern>
</servlet-mapping>

<welcome-file-list>

<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

36.</web-app>

2 重构helloworld应用案例

2.1 问题

使用注解的方式重构helloworld应用案例。

2.2 方案

1. @RequestMapping注解应用

@RequestMapping可以用在类定义和方法定义上，它标明这个类或方法与哪一个客户请求对应。实例代码如下：

1.  @RequestMapping("/day01")

2.  public class HelloController{

3.      @RequestMapping("/hello.form")

4.      public String execute() throws Exception {

5.          return "hello";

6.      }

7.  }

@RequestMapping("/day01")

public class HelloController{

 @RequestMapping("/hello.form")

 public String execute() throws Exception {

  return "hello";

2. 开启@RequestMapping注解映射，需要在Spring的XML配置文件进行配置，配置代码如下：

1.  <mvc:annotation-driven/>

3. @Controller注解应用

推荐使用@Controller注解声明Controller组件，这样可以使得Controller定义更加灵活，可以不用实现Controller接口，请求处理的方法也可以灵活定义。代码如下：

@Controller
@RequestMapping("/day01")
public class HelloController{
@RequestMapping("/hello.form")
public String execute() throws Exception {
return "hello";
}
}

#cold_bold@Controller

@RequestMapping("/day01")

public class HelloController{

@RequestMapping("/hello.form")

public String execute() throws Exception {

return "hello";

}

4. 为了使@Controller注解生效，需要在Spring的XML配置文件中开启组件扫描定义，并指定Controller组件所在包，配置代码如下：

<context:component-scan base-package="com.tarena.controller"/>

2.4 完整代码

HelloController类的完整代码如下所示：

1.  package com.tarena.controller;

2.  import org.springframework.stereotype.Controller;

3.  import org.springframework.web.bind.annotation.RequestMapping;

4.  @Controller

5.  @RequestMapping("/day01")

6.  public class HelloController{

7.      @RequestMapping("/hello.form")

8.      public String execute() throws Exception {

9.          return "hello";

10.    }

11.}

spring-mvc.xml文件的完整代码如下所示：

<?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:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
<context:component-scan base-package="com.tarena.controller"/>
<mvc:annotation-driven/>

31.<!--

<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/>

37. -->

<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/">
</property>
<property name="suffix" value=".jsp">
</property>
</bean>

53.</beans>

发表于 2014-12-20 17:23 小小程序员J211 阅读(210) 评论(0) 收藏举报