Restlet 2.0 與 Spring集成，並遵循JAX-RS標準，JSR311

      先聲明我只是給出一個work-around plan，還有些不盡如人意的地方（文章最後會指出）。

首先，給出web.xml 和spring cofng xml

• web.xml

<?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">
        <filter>
        	<filter-name>EncodingFilter</filter-name>
			<filter-class>org.brianlabs.filter.EncodingFilter</filter-class>
			<init-param>
				<param-name>encoding</param-name>
				<param-value>utf-8</param-value>
			</init-param>
		</filter>
		<filter-mapping>
			<filter-name>EncodingFilter</filter-name>
			<url-pattern>/*</url-pattern>
		</filter-mapping>

        <servlet>
        	<servlet-name>restserver</servlet-name>
        	<servlet-class>org.restlet.ext.spring.RestletFrameworkServlet</servlet-class>
        	<load-on-startup>1</load-on-startup>
        	<init-param>
        		<param-name>contextConfigLocation</param-name>
        		<param-value>classpath:/ApplicationContext-restlet.xml</param-value>
        	</init-param>
        </servlet>
        <servlet-mapping>
        	<servlet-name>restserver</servlet-name>
        	<url-pattern>/*</url-pattern>
        </servlet-mapping>
    </web-app>

• ApplicationContext-restlet.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:util="http://www.springframework.org/schema/util"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:task="http://www.springframework.org/schema/task"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
        http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd" >


    <bean id="root" class="org.restlet.ext.spring.SpringComponent">
        <property name="defaultTarget" ref="restServer" />
    </bean>
    
    <bean id="restServer" class="org.restlet.ext.jaxrs.JaxRsApplication">
        <property name="objectFactory" ref="springJaxObjectFactory"/>
        <property name="applications" ref="springJaxConfig"/>
    </bean>
    
    <bean id="root.context" class="org.springframework.beans.factory.config.PropertyPathFactoryBean"/>
    
    <bean id="springJaxObjectFactory" class="org.brianlabs.restlet.spring.SpringJaxObjectFactory">
        <constructor-arg ref="jaxBeanCollection" />
    </bean>

    <bean id="springJaxConfig" class="org.brianlabs.restlet.spring.SpringJaxConfig">
        <constructor-arg ref="jaxBeanCollection" />
    </bean>
    
     <bean id="jaxBeanCollection" class="org.brianlabs.restlet.spring.JaxBeanCollection">
        <property name="beanNames">
            <list>
                <value>helloWorldResource</value>
            </list>
        </property>
    </bean>
    
    <bean id="helloWorldResource" class="org.brianlabs.restlet.resources.HelloWorldresource" scope="prototype" />
    
</beans>

• SpringJaxObjectFactory

package org.brianlabs.restlet.spring;


import org.restlet.ext.jaxrs.InstantiateException;
import org.restlet.ext.jaxrs.ObjectFactory;

/**
* The spring-friendly class responsible for configuring the jax-rs object construction.
* @author Brian Ling
*
*/
public class SpringJaxObjectFactory implements ObjectFactory {
   /** The jax-bean collection that drives this component. **/
   private JaxBeanCollection myBeanCollection;

   /**
    * Create the Spring Jax Object Factory.
    * @param beanCollection The jax-bean collection that will drive this component.
    */
   public SpringJaxObjectFactory(final JaxBeanCollection beanCollection) {
       this.myBeanCollection = beanCollection;
   }

   @Override
   public <T> T getInstance(final Class<T> jaxRsClass) throws InstantiateException {
       T bean = myBeanCollection.getBean(jaxRsClass);
       return bean;
   }
}

SprinJaxConfig

package org.brianlabs.restlet.spring;

import java.util.Set;


/**
 * The spring-friendly class responsible for configuring the jax-rs context.
 * @author Brian Ling
 *
 */
public class SpringJaxConfig extends javax.ws.rs.core.Application {
    /** The jax-bean collection that drives this component. **/
    private JaxBeanCollection myBeanCollection;

    /**
     * Create the Spring Jax Config.
     * @param beanCollection The jax-bean collection that will drive this component.
     */
    public SpringJaxConfig(final JaxBeanCollection beanCollection) {
        this.myBeanCollection = beanCollection;
    }

    @Override
    public Set<Class<?>> getClasses() {
        return myBeanCollection.getBeanTypes();
    }
}

• HelloWorldresource

package org.brianlabs.restlet.resources;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

import org.brianlabs.restlet.RestDictionary;

@Path(RestDictionary.BASE_HELLO_WORLD_PATH)
public class HelloWorldresource extends StandardResource {
	
	@GET
	@Produces("text/plain")
	public String getPlain() {
		return "This is an easy resource (as plain text)";
	}
}

• RestDictionary

package org.brianlabs.restlet;

public class RestDictionary {
	public final static String BASE_HELLO_WORLD_PATH="/restlet/hello";
	public static final String JSON_OUTPUT = "application/json";
	public static final String HTML_TEXT_OUTPUT = "text/html";
	public static final String ID = "id";
}

不足：

1.    解析path對應到具體Resource Class時，需要考慮到context的root path，如果在servlet request propogate的時候，修改URL也是個work around 方法，可以參考http://code.google.com/p/urlrewritefilter/

2. id爲jaxBeanCollection的Spring Bean，繼承於org.springframework.beans.factory.BeanFactoryAware，在spring配置裏再嵌套個BeanFactory，似乎有些可以簡化的地方。

附錄：

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>org.brianlabs</groupId>
	<artifactId>restlet</artifactId>
	<packaging>war</packaging>
	<version>0.0.1-SNAPSHOT</version>
	<name>restlet J2EE 1.4 Webapp</name>
	<url>http://maven.apache.org</url>
	<dependencies>

		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>servlet-api</artifactId>
			<version>2.4</version>
			<scope>provided</scope>
		</dependency>

		<dependency>
			<groupId>javax.servlet.jsp</groupId>
			<artifactId>jsp-api</artifactId>
			<version>2.1</version>
			<scope>provided</scope>
		</dependency>


		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>3.8.1</version>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>org.restlet.jee</groupId>
			<artifactId>org.restlet.ext.spring</artifactId>
			<version>2.0.9</version>
		</dependency>
		<dependency>
			<groupId>org.restlet.jee</groupId>
			<artifactId>org.restlet</artifactId>
			<version>2.0.9</version>
		</dependency>
		<dependency>
			<groupId>org.restlet.jee</groupId>
			<artifactId>org.restlet.ext.jaxrs</artifactId>
			<version>2.0.9</version>
		</dependency>

		<dependency>
			<groupId>log4j</groupId>
			<artifactId>log4j</artifactId>
			<version>1.2.15</version>
			<exclusions>
				<exclusion>
					<groupId>javax.mail</groupId>
					<artifactId>mail</artifactId>
				</exclusion>
				<exclusion>
					<groupId>javax.jms</groupId>
					<artifactId>jms</artifactId>
				</exclusion>
				<exclusion>
					<groupId>com.sun.jdmk</groupId>
					<artifactId>jmxtools</artifactId>
				</exclusion>
				<exclusion>
					<groupId>com.sun.jmx</groupId>
					<artifactId>jmxri</artifactId>
				</exclusion>
			</exclusions>
		</dependency>
	</dependencies>
	<build>
		<plugins>
			<plugin>
				<groupId>org.apache.maven.plugins</groupId>
				<artifactId>maven-compiler-plugin</artifactId>
				<version>2.0.2</version>
				<configuration>
					<source>1.6</source>
					<target>1.6</target>
				</configuration>
			</plugin>
		</plugins>
		<finalName>restlet</finalName>
	</build>

	<repositories>
		<repository>
			<id>maven-restlet</id>
			<name>Public online Restlet repository</name>
			<url>http://maven.restlet.org</url>
		</repository>
	</repositories>
</project>