关于REST是什么东西,在这里我就不再多说,大家可以去http://blog.csdn.net/pilou5400/archive/2010/12/24/6096861.aspx看看介绍,直接切入主题:
这是一个rest风格的访问,Spring从3.0开始将全面支持rest。不得不感叹Spring的强悍。
项目结构
第一步永远是配置,使用框架永远都是先有配置,在web.xml中的配置:
<?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> <context-param> <!--rest配置文件的路径,貌似不配置也是加载这个地址,这个地方有点疑问,大家指点指点--> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/rest-servlet.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <servlet> <!-- 配置一个Servlet,有这个Servlet统一调度页面的请求 --> <servlet-name>rest</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <load-on-startup>2</load-on-startup> </servlet> <servlet-mapping> <!-- 映射路径,不要写成了/*那样会拦截所有的访问,连JSP页面都访问不了 --> <servlet-name>rest</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>/index.jsp</welcome-file> </welcome-file-list> </web-app>
第二步:配置rest-servlet.xml这个文件
<?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:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-2.5.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd" default-lazy-init="true"> <description>Spring公共配置</description> <!--检测注解--> <context:component-scan base-package="com.liqiu" /> <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping" /> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" /> <!-- 注册视图解析器,说白了就是根据返回值指定到某个页面 --> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/"></property> <!--页面文件的路径,在根目录下--> </bean> </beans>
第三步:具体实现类
package com.liqiu.controller; import java.io.IOException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; @Controller @RequestMapping("/simple") public class SimpleController { //映射路径/simple/index当访问这个路径时,执行这个方法 @RequestMapping("/index") public String index(HttpServletRequest request ,HttpServletResponse response){ //response,request会自动传进来 request.setAttribute("message", "Hello,This is a example of Spring3 RESTful!"); return "index.jsp"; } //根据ID获取不同的内容,通过@PathVariable 获得属性 @RequestMapping(value="/{id}",method=RequestMethod.GET) public String get(@PathVariable String id,HttpServletRequest request ,HttpServletResponse response) throws IOException{ request.setAttribute("message", "Hello,This is a example of Spring3 RESTful!<br/>ID:"+id+""); //response.getWriter().write("You put id is : "+id); return "index.jsp"; //return null; } }
index.jsp页面:
<%@ page language="java" pageEncoding="UTF-8"%> <html> <head> <title>Spring3 RESTful</title> </head> <body> ${message} </body> </html>
在浏览器中输入:http://localhost:8080/SpringREST/simple/index/,就可以看到效果。
也可以在页面输入不同的参数,获得不同的内容,输入地址:http://localhost:8080/SpringREST/simple/88888,这次执行的就是get方法,通过注解获取ID值
关于Spring rest 对于Ajax的支持,其实响应Ajax就是通过response返回一个字符串到页面,既然能获得response对象,那问题就迎刃而解了,我们改造下get方法:
@RequestMapping(value="/{id}",method=RequestMethod.GET) public String get(@PathVariable String id,HttpServletRequest request ,HttpServletResponse response) throws IOException{ //request.setAttribute("message", "Hello,This is a example of Spring3 RESTful!<br/>ID:"+id+""); response.getWriter().write("You put id is : "+id); //return "index.jsp"; return null; }
改造index.jsp页面:
<%@ page language="java" pageEncoding="UTF-8"%> <html> <head> <title>Spring3 RESTful</title> <SCRIPT TYPE="text/javascript"> function go(value){ var url = "/SpringREST/simple/"+value+"/"; var request = new XMLHttpRequest(); request.open("GET", url, true); request.setRequestHeader("Content-Type","application/x-javascript;"); request.onreadystatechange = function() { if (request.readyState == 4) { if (request.status == 200){ if (request.responseText) { document.getElementById("text").innerHTML = request.responseText; } } } }; request.send(null); } </SCRIPT> </head> <body> ${message} <br> Input the id of you will access object:<input id="id" type="text" size="7"><input type="button" value="Go" onclick="go(document.getElementById('id').value)"> <div id="text"></div> </body> </html>
访问http://localhost:8080/SpringREST/simple/index/,在页面里的输入框中输入值,可以看到返回的数据