Restlet 2.0 边学边写（四）Restlet与spring集成

上一次实践是使用Component来发布多个Resource。本次实践将Restlet与spring集成，并使用spring来配置、发布、管理多个Resource。

参考： http://ajaxcn.iteye.com/blog/416913

本次实践需要导入spring相关包，创建配置文件applicationContext.xml并进行配置。

1.导入spring相关包
将Restlet安装目录\Edition Java EE\2.0.10\lib下的org.restlet.ext.spring.jar、net.sf.cglib.jar 两个包和spring.jar包加入Build Path，我使用的是spring2.0。

2.Dao
在com.sunny.restlet.order目录下创建OrderDao接口，代码如下：

package com.sunny.restlet.order;

public interface OrderDao {

	public String getOrderById(String orderId);

	public String getSubOrderById(String subOrderId);

	public String getCustomerById(String custId);

}

接口中定义数据访问方法。

在com.sunny.restlet.order目录下创建OrderDaoImpl类，代码如下：

package com.sunny.restlet.order;

public class OrderDaoImpl implements OrderDao {

	public String getCustomerById(String custId) {
		// TODO Auto-generated method stub
		return "customer" + custId;
	}

	public String getOrderById(String orderId) {
		// TODO Auto-generated method stub
		return "order" + orderId;
	}

	public String getSubOrderById(String subOrderId) {
		// TODO Auto-generated method stub
		return "subOrder" + subOrderId;
	}

}

类实现了OrderDao接口。

3.Resource
修改com.sunny.restlet.order.CustomerResource类，代码如下：

package com.sunny.restlet.order;

import org.restlet.resource.Get;
import org.restlet.resource.ResourceException;
import org.restlet.resource.ServerResource;

public class CustomerResource extends ServerResource {
	String customerId = "";

	private OrderDao orderDao;
	
	@Override
	protected void doInit() throws ResourceException {
		this.customerId = (String) getRequest().getAttributes().get("custId");
	}

	@Get
	public String represent() {
		return "get customer id :" + orderDao.getCustomerById(customerId) ;
	}

	public void setOrderDao(OrderDao orderDao) {
		this.orderDao = orderDao;
	}

}

修改后的类相当于spring中的service bean，类中调用了orderDao的数据访问接口。

修改com.sunny.restlet.order.OrderResource类，代码如下：

package com.sunny.restlet.order;

import org.restlet.resource.Get;
import org.restlet.resource.ResourceException;
import org.restlet.resource.ServerResource;

public class OrderResource extends ServerResource {
	String orderId = "";
	String subOrderId = "";

	private OrderDao orderDao;

	@Override
	protected void doInit() throws ResourceException {
		this.orderId = (String) getRequest().getAttributes().get("orderId");
		this.subOrderId = (String) getRequest().getAttributes().get(
				"subOrderId");
	}

	@Get
	public String represent() {
		return "the order id is : " + orderDao.getOrderById(orderId)
				+ " and the sub order id is : "
				+ orderDao.getSubOrderById(subOrderId);
	}

	public void setOrderDao(OrderDao orderDao) {
		this.orderDao = orderDao;
	}
}

4.applicationContext.xml
在src/下创建spring配置文件applicationContext.xml，代码如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans default-autowire="byName"
	xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:util="http://www.springframework.org/schema/util"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
	<!-- component -->
	<bean id="component" class="org.restlet.ext.spring.SpringComponent">
		<property name="defaultTarget" ref="restRouter" />
	</bean>
	<!-- router -->
	<bean id="restRouter" class="org.restlet.ext.spring.SpringBeanRouter">
	</bean>
	<!-- resource -->
	<bean name="/customers/{custId}" id="customerResrouce"
		class="com.sunny.restlet.order.CustomerResource" />
	<bean name="/orders/{orderId}/{subOrderId}" id="orderResrouce"
		class="com.sunny.restlet.order.OrderResource" />
	<!-- dao -->
	<bean id="orderDao" class="com.sunny.restlet.order.OrderDaoImpl" />
</beans>  

文件中定义了component、router、resource和dao，以及将Resource发布到的路径。使用spring不需要再自定义Component和Application。

5.web.xml
修改web.xml文件，删除原有Restlet配置，加入spring配置，代码如下：

<?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">
	<!-- spring -->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath*:applicationContext*.xml</param-value>
	</context-param>
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>
	<!-- SpringServerServlet -->
	<servlet>
		<servlet-name>restlet</servlet-name>
		<servlet-class>org.restlet.ext.spring.SpringServerServlet</servlet-class>
		<init-param>
			<param-name>org.restlet.component</param-name>
			<param-value>component</param-value>
		</init-param>
	</servlet>
	<servlet-mapping>
		<servlet-name>restlet</servlet-name>
		<url-pattern>/spring/*</url-pattern>
	</servlet-mapping>
	<!-- welcome-file-list -->
	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
</web-app>

文件中定义spring配置文件位置，指定使用SpringServerServlet来提供服务，并定义了在spring配置中Component Bean的id（component）。

6.运行
重新部署后，通过浏览器访问 http://localhost:8080/firstSteps/spring/customers/1可以看到提示信息

• get customer id :customer1

访问 http://localhost:8080/firstSteps/spring/orders/1/2可以看到提示信息

• the order id is : order1 and the sub order id is : subOrder2

说明Restlet和spring集成成功。

7.SpringRouter
SpringBeanRouter要求resource继承ServerResource类，自动将spring BeanFactory中name以"/"开头的bean加到路径上。

除此外还可以使用SpringRouter来集成，applicationContext.xml代码如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans default-autowire="byName"
	xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:util="http://www.springframework.org/schema/util"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
	<!-- component -->
	<bean id="component" class="org.restlet.ext.spring.SpringComponent">
		<property name="defaultTarget" ref="restRouter" />
	</bean>
	<!-- router -->
	<bean id="restRouter" class="org.restlet.ext.spring.SpringRouter">
		<property name="attachments">
			<map>
				<entry key="/customers/{custId}">
					<bean class="org.restlet.ext.spring.SpringFinder">
						<lookup-method name="create" bean="customerResource" />
					</bean>
				</entry>
				<entry key="/orders/{orderId}/{subOrderId}">
					<bean class="org.restlet.ext.spring.SpringFinder">
						<lookup-method name="create" bean="orderResource" />
					</bean>
				</entry>
			</map>
		</property>
	</bean>
	<!-- resource -->
	<bean id="customerResource" class="com.sunny.restlet.order.CustomerResource">
	</bean>
	<bean id="orderResource" class="com.sunny.restlet.order.OrderResource">
	</bean>
	<!-- dao -->
	<bean id="orderDao" class="com.sunny.restlet.order.OrderDaoImpl" />
</beans>  

SpringRouter调用SpringFinder，需要指定lookup-method，如果resource继承自Resource，则name="createResource"，且resource要实现无参构造函数和init()方法；如果resource继承自ServerResource，则name="create"。详情请参考Restlet源码，SpringFinder类中的createTarget(Request request, Response response)、createResource()和create()方法，SpringBeanFinder类中的create()方法。

8.RestletFrameworkServlet
还可以使用RestletFrameworkServlet替代SpringServerServlet。这需要导入spring-webmvc.jar包。
修改web.xml，代码如下：

<?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">
	<!-- SpringServerServlet -->
	<servlet>
		<servlet-name>restlet</servlet-name>
		<servlet-class>org.restlet.ext.spring.RestletFrameworkServlet</servlet-class>
		<init-param>
			<param-name>targetRestletBeanName</param-name>
			<param-value>restRouter</param-value>
		</init-param>
	</servlet>
	<servlet-mapping>
		<servlet-name>restlet</servlet-name>
		<url-pattern>/spring/*</url-pattern>
	</servlet-mapping>
	<!-- welcome-file-list -->
	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>
</web-app>

代码中将targetRestletBeanName这个init-param的值设定为restRouter，如果不设置，默认为root。RestletFrameworkServlet根据这个参数的值从WEB-INF\restlet-servlet.xml中读取配置。
在WEB-INF目录下创建restlet-servlet.xml，代码如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans default-autowire="byName"
	xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:util="http://www.springframework.org/schema/util"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
	<!-- router -->
	<bean id="restRouter" class="org.restlet.ext.spring.SpringBeanRouter">
	</bean>
	<!-- resource -->
	<bean name="/customers/{custId}" id="customerResrouce"
		class="com.sunny.restlet.order.CustomerResource" />
	<bean name="/orders/{orderId}/{subOrderId}" id="orderResrouce"
		class="com.sunny.restlet.order.OrderResource" />
	<!-- dao -->
	<bean id="orderDao" class="com.sunny.restlet.order.OrderDaoImpl" />
</beans>