教大家看官方技术文档(一)- Spring MVC (续)
续上一篇文章,继续看看如何配置controller实现跳转
第一步: 设置controller class
Spring MVC(Part VI. The Web)
21.3 Implementing Controllers:
http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#mvc-controller
在Struct或者Servlet的世界,实现Url的mapping是在xml里配置的,Spring MVC可以直接在Controller的source里用@Controller标注,然后用@RequestMapping标注Url的mapping执行相应的方法。
@Controller
public class HelloWorldController {
@RequestMapping("/helloWorld")
public String helloWorld(Model model) {
model.addAttribute("message", "Hello World!");
return "helloWorld";
}
}
第二步: 配置spring上下文xml
那么如何让DispatcherServlet找到这个controller作为url的mapping呢?继续看文档,有如下例子:
<context:component-scan base-package="org.springframework.samples.petclinic.web"/>
(其实官方文档有个不好的地方,就是例子的不连贯性,感觉好似是从不同project例子里粘贴代码过来,例如前面用HelloWorldController,这里是petclinic)
如果你有经验或者理解力好的话,文档的意思是component-scan会在base-package 指定路径下扫描所有的java source,凡是用了@Controller标注的controller都用来做Url的mapping。 所以把该component-scan标签加入到spring的上下文xml (本文例子对应mvc-core-config.xml)。
综上所述,配置如下:
1)HelloWorldController.java
package main.java.webController;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HelloWorldController {
@RequestMapping("/helloWorld")
public String helloWorld(Model model) {
model.addAttribute("message", "Hello World!");
return "helloWorld";
}
}
2) web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Archetype Created Web Application</display-name>
<!--
- Location of the XML file that defines the root application context.
- Applied by ContextLoaderListener.
-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value></param-value>
</context-param>
<!--
- Servlet that dispatches request to registered handlers (Controller implementations).
-->
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/mvc-core-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/*</url-pattern>
</servlet-mapping>
</web-app>
3) spring/mvc-core-config.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.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="main.java.webController"/>
<mvc:view-resolvers>
<mvc:content-negotiation use-not-acceptable="true">
<mvc:default-views>
<bean class="org.springframework.web.servlet.view.JstlView">
<property name="url" value=""/>
</bean>
</mvc:default-views>
</mvc:content-negotiation>
<!-- Registering BeanNameViewResolver and InternalViewResolver -->
<mvc:bean-name/>
<mvc:jsp prefix="/WEB-INF/jsp/" suffix=".jsp"/>
</mvc:view-resolvers>
</beans>
4)HelloWorldController对应的JSP页面:
文件位置:webapp/WEB-INF/jsp/helloWorld.jsp
<html>
<body>
<h2>Spring Hello World Matthew!</h2>
</body>
</html>
运行http://localhost:8080/helloWorld成功显示页面。
至此,一个简单的Spring MVC跳转模型基本实现。更多高级应用,此处不深入,这里想说的只是很多网友的例子的根源其实都是来自官方文档的。要想深入挖掘更多功能和了解Spring版本最新的用法,大家不妨看看官方技术文档。
下篇文章,将会尝试从官方文档看看如何用Spring整合Mybatis。