Spring3.0实现REST实例
Spring从3.0开始将全面支持rest。不得不感叹Spring的强大。
项目结构：
第一步：配置web.xml文件
<?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>
<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.bijian" />
<bean
/>
<bean
/>
<!-- 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"
/>
<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.bijian.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,这是一个Spring3 REST的实例！");
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,这是一个Spring3 REST的实例！<br/>ID:"+id+"");
//response.getWriter().write("You put id is : "+id);
return "index.jsp";
//return null;
}
}
第四步：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/SpringREST2/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/SpringREST2/simple/abc，这次执行的就是get方法，通过注解获取ID值，效果：
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：
//根据ID获取不同的内容，通过@PathVariable 获得属性
@RequestMapping(value="/{id}",method=RequestMethod.GET)
publicString get(@PathVariableString id,HttpServletRequest request ,HttpServletResponse response) throws IOException{
//request.setAttribute("message", "Hello,这是一个Spring3 REST的实例！<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 = "/SpringREST2/simple/"+value+"/";
var request = newXMLHttpRequest();
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.getElementByIdx_x_x_x_x("text").innerHTML = request.responseText;
}
}
}
};
request.send(null);
}
</SCRIPT>
</head>
<body>
${message}
<br>
请输入您将访问的Id标识:<input id="id" type="text" size="7"><input type="button" value="Go" onclick="go(document.getElementByIdx_x_x_x_x('id').value)">
<div id="text"></div>
</body>
</html>
访问http://localhost:8080/SpringREST2/simple/index，在页面里的输入框中输入值，可以看到返回的数据： 