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http://www.cnblogs.com/hoojo/archive/2011/06/10/2077422.html

前面介绍过Spring的MVC结合不同的view显示不同的数据,如:结合json的 view显示json、结合xml的view显示xml文档。那么这些数据除了在WebBrowser中用JavaScript来调用以外,还可以用远程 服务器的Java程序、C#程序来调用。也就是说现在的程序不仅在BS中能调用,在CS中同样也能调用,不过你需要借助RestTemplate这个类来 完成。RestTemplate有点类似于一个WebService客户端请求的模版,可以调用http请求的WebService,并将结果转换成相应 的对象类型。至少你可以这样理解!

 

上一次博文介绍SpringMVC结合不同的View,显示不同的数据。http://www.cnblogs.com/hoojo/archive/2011/04/29/2032571.html

 

Email:hoojo_@126.com

Blog:http://blog.csdn.net/IBM_hoojo

http://hoojo.cnblogs.com/

 

一、准备工作

1、 下载jar包

spring各版本jar下载地址:http://ebr.springsource.com/repository/app/library/detail?name=org.springframework.spring

相关的依赖包也可以在这里找到:http://ebr.springsource.com/repository/app/library

 

2、 需要jar包如下

clip_image002

 

3、 当前工程的web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" 
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
    
    <!-- 配置Spring核心控制器 -->
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/dispatcher.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>*.do</url-pattern>
    </servlet-mapping>
    
    <welcome-file-list>
      <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

4、 WEB-INF中的dispatcher.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.0.xsd
    http://www.springframework.org/schema/util
    http://www.springframework.org/schema/util/spring-util-3.0.xsd">
 
    <context:component-scan base-package="com.hoo.*">
        <!-- 忽略这个类 -->
        <context:exclude-filter type="assignable" expression="com.hoo.client.RESTClient"/>
    </context:component-scan>
 
    <!-- annotation的方法映射适配器 -->
    <bean id="handlerAdapter" class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
    
    <!-- xml视图,XStreamMarshaller,可以转换任何形式的java对象 -->
    <bean name="xStreamMarshallingView" class="org.springframework.web.servlet.view.xml.MarshallingView">
        <property name="marshaller">
            <bean class="org.springframework.oxm.xstream.XStreamMarshaller">  
                <!--  为了初始化XStreamMarshaller,这个类会把我们接口中得到结果以XML文档形式展现出来 -->
                <property name="autodetectAnnotations" value="true"/>  
            </bean>  
        </property>
    </bean>
        
    <!-- 视图解析器,根据视图的名称new ModelAndView(name),在配置文件查找对应的bean配置 -->
    <bean class="org.springframework.web.servlet.view.BeanNameViewResolver">
        <property name="order" value="3"/>
    </bean>
 
    <!--  annotation默认的方法映射适配器 -->
    <bean id="handlerMapping" class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping">
        <property name="order" value="1" />
    </bean>
    
</beans>

5、 启动后,可以看到index.jsp 没有出现异常或错误。那么当前SpringMVC的配置就成功了。

 

二、REST控制器实现

REST控制器主要完成CRUD操作,也就是对于http中的post、get、put、delete。

还有其他的操作,如head、options、trace。

具体代码:

package com.hoo.controller;
 
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;
import org.springframework.web.servlet.ModelAndView;
 
/**
 * <b>function:</b>SpringMVC REST示例
 * @author hoojo
 * @createDate 2011-6-9 上午11:34:08
 * @file RESTController.java
 * @package com.hoo.controller
 * @project SpringRestWS
 * @blog http://blog.csdn.net/IBM_hoojo
 * @email hoojo_@126.com
 * @version 1.0
 */
@RequestMapping("/restful")
@Controller
public class RESTController {
    
    @RequestMapping(value = "/show", method = RequestMethod.GET)
    public ModelAndView show() {
        System.out.println("show");
        ModelAndView model = new ModelAndView("xStreamMarshallingView");
        model.addObject("show method");
        return model; 
    }
    
    @RequestMapping(value = "/get/{id}", method = RequestMethod.GET)
    public ModelAndView getUserById(@PathVariable String id) {
        System.out.println("getUserById-" + id);
        ModelAndView model = new ModelAndView("xStreamMarshallingView");
        model.addObject("getUserById method -" + id);
        return model; 
    }
    
    @RequestMapping(value = "/add", method = RequestMethod.POST)
    public ModelAndView addUser(String user) {
        System.out.println("addUser-" + user);
        ModelAndView model = new ModelAndView("xStreamMarshallingView");
        model.addObject("addUser method -" + user);
        return model; 
    }
    
    @RequestMapping(value = "/edit", method = RequestMethod.PUT)
    public ModelAndView editUser(String user) {
        System.out.println("editUser-" + user);
        ModelAndView model = new ModelAndView("xStreamMarshallingView");
        model.addObject("editUser method -" + user);
        return model;
    }
    
    @RequestMapping(value = "/remove/{id}", method = RequestMethod.DELETE)
    public ModelAndView removeUser(@PathVariable String id) {
        System.out.println("removeUser-" + id);
        ModelAndView model = new ModelAndView("xStreamMarshallingView");
        model.addObject("removeUser method -" + id);
        return model;
    }
}

上面的方法对应的http操作:

/show -> get 查询
/get/id -> get 查询
/add -> post 添加
/edit -> put 修改
/remove/id -> delete 删除

在这个方法中,就可以看到RESTful风格的url资源标识

@RequestMapping(value = "/get/{id}", method = RequestMethod.GET)
public ModelAndView getUserById(@PathVariable String id) {
    System.out.println("getUserById-" + id);
    ModelAndView model = new ModelAndView("xStreamMarshallingView");
    model.addObject("getUserById method -" + id);
    return model; 
}

value=”/get/{id}”就是url中包含get,并且带有id参数的get请求,就会执行这个方法。这个url在请求的时候,会通过 Annotation的@PathVariable来将url中的id值设置到getUserById的参数中去。 ModelAndView返回的视图是xStreamMarshallingView是一个xml视图,执行当前请求后,会显示一篇xml文档。文档的内 容是添加到model中的值。

 

三、利用RestTemplate调用REST资源

代码如下:

package com.hoo.client;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;
 
/**
 * <b>function:</b>RestTemplate调用REST资源
 * @author hoojo
 * @createDate 2011-6-9 上午11:56:16
 * @file RESTClient.java
 * @package com.hoo.client
 * @project SpringRestWS
 * @blog http://blog.csdn.net/IBM_hoojo
 * @email hoojo_@126.com
 * @version 1.0
 */
@Component
public class RESTClient {
    
    @Autowired
    private RestTemplate template;
    
    private final static String url = "http://localhost:8080/SpringRestWS/restful/";
    
    public String show() {
        return template.getForObject(url + "show.do", String.class, new String[]{});
    }
    
    public String getUserById(String id) {
        return template.getForObject(url + "get/{id}.do", String.class, id); 
    }
    
    public String addUser(String user) {
        return template.postForObject(url + "add.do?user={user}", null, String.class, user);
    }
    
    public String editUser(String user) {
        template.put(url + "edit.do?user={user}", null, user);
        return user;
    }
    
    public String removeUser(String id) {
        template.delete(url + "/remove/{id}.do", id);
        return id;
    }
}

RestTemplate的getForObject完成get请求、postForObject完成post请求、put对应的完成put请求、 delete完成delete请求;还有execute可以执行任何请求的方法,需要你设置RequestMethod来指定当前请求类型。

RestTemplate.getForObject(String url, Class<String> responseType, String... urlVariables)

参数url是http请求的地址,参数Class是请求响应返回后的数据的类型,最后一个参数是请求中需要设置的参数。

template.getForObject(url + "get/{id}.do", String.class, id);

如上面的参数是{id},返回的是一个string类型,设置的参数是id。最后执行该方法会返回一个String类型的结果。

 

下面建立一个测试类,完成对RESTClient的测试。代码如下:

package com.hoo.client;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit38.AbstractJUnit38SpringContextTests;
 
/**
 * <b>function:</b>RESTClient TEST
 * @author hoojo
 * @createDate 2011-6-9 下午03:50:21
 * @file RESTClientTest.java
 * @package com.hoo.client
 * @project SpringRestWS
 * @blog http://blog.csdn.net/IBM_hoojo
 * @email hoojo_@126.com
 * @version 1.0
 */
@ContextConfiguration("classpath:applicationContext-*.xml")
public class RESTClientTest extends AbstractJUnit38SpringContextTests {
    
    @Autowired
    private RESTClient client;
    
    public void testShow() {
        System.out.println(client.show());
    }
    
    public void testGetUserById() {
        System.out.println(client.getUserById("abc"));
    }
    
    public void testAddUser() {
        System.out.println(client.addUser("jack"));
    }
    
    public void testEditUser() {
        System.out.println(client.editUser("tom"));
    }
    
    public void testRemoveUser() {
        System.out.println(client.removeUser("aabb"));
    }
}

我们需要在src目录下添加applicationContext-beans.xml完成对restTemplate的配置。restTemplate需要配置MessageConvert将返回的xml文档进行转换,解析成JavaObject。

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    
    <context:component-scan base-package="com.hoo.*"/>
    
    <bean id="restTemplate" class="org.springframework.web.client.RestTemplate">
        <property name="messageConverters">
            <list>
                <bean class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter">
                    <property name="marshaller" ref="xStreamMarshaller"/>
                    <property name="unmarshaller" ref="xStreamMarshaller"/>
                </bean>
            </list>
        </property>
    </bean>
    
    <bean id="xStreamMarshaller" class="org.springframework.oxm.xstream.XStreamMarshaller">
        <property name="annotatedClasses">
            <array>                
            </array>
        </property>
    </bean>
</beans>

上面配置了xStreamMarshaller是和RESTController中的ModelAndView的view对应的。因为那边是用 xStreamMarshaller进行编组的,所以RestTemplate这边也需要用它来解组。RestTemplate还指出其他的 MarshallingHttpMessageConverter;

posted on 2012-09-05 13:39 SIMONE 阅读(2468) 评论(0)  编辑  收藏 所属分类: JAVA

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