使用resteasy作为dubbox消费者

　　dubbox服务提供者是REST风格的，消费者可能是从dubbox过来的，也可能是从第三方外部系统过来的。后者的话我们没得选，只能以服务提供者直连，服务治理平台和监控中心手再长，也管不到别人的地盘。但如果是dubbox自己作为消费端，那么就可以很容易配置各种服务治理参数了，也能被监控中心实时盯着。有利必有弊，本来dubbox提供REST风格的http调用就是为了方便异构客户端到服务提供者来交流的，为了纳入dubbo系统再套一层消费者岂不是脱裤子放屁，多此一举？多了一个人传话，对话就多了一层转换，多了一份丢话和失真的危险。

　　消费端用spring的REST注解是最简单的，但因为服务端已经用dubbox的RESTEasy框架了，所以消费端还得重新用spring自己的REST实现一遍。这里为了偷懒，消费端还是用RESTEasy来搞，直接把服务端用到的公共接口复制到消费端作为控制类即可。首先我们用JAX-RS定义接口和bean，放到公用API包里，然后服务端实现这些API，消费端新增一个controller类来调用API，最后在web配置文件里指定使用RESTEasy作为servlet容器。

1、公用接口，使用JAX-RS注解，暴露服务端所提供的服务

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;
import com.wlf.api.bean.Page;

@Path("/hello/world")
@Produces({MediaType.APPLICATION_JSON})
public interface MobileZoneResourceService
{
    @GET
    @Path("/nihao.jsp")
    public Page queryToday(@QueryParam("param") String param);
}     

公用bean，使用JAX-RS注解

import java.io.Serializable;
import java.util.List;
import java.util.Map;

import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement
public class Page implements Serializable
{

    private static final long serialVersionUID = -680237712312747858L;

    private Integer start;
    
    private Integer pageSize;
    
    private Integer totalSize;
    
    public Integer getStart()
    {
        return start;
    }
    
    public void setStart(Integer start)
    {
        this.start = start;
    }
    
    public Integer getPageSize()
    {
        return pageSize;
    }
    
    public void setPageSize(Integer pageSize)
    {
        this.pageSize = pageSize;
    }
    
    public Integer getTotalSize()
    {
        return totalSize;
    }
    
    public void setTotalSize(Integer totalSize)
    {
        this.totalSize = totalSize;
    }
}

2、服务提供者service类，注入DAO接口

import org.codehaus.jackson.map.ObjectMapper;
import org.springframework.beans.factory.annotation.Autowired;

import com.wulf.zoneresource.api.MobileZoneResourceService;
import com.wulf.zoneresource.api.bean.Page;
import com.wulf.zoneresource.provider.bean.BpmUserInfo;
import com.wulf.zoneresource.provider.dao.ZoneResourceService;

public class MobileZoneResourceServiceImpl implements MobileZoneResourceService
{
    @Autowired
    private ZoneResourceService zoneResourceService;
    
    public Page queryToday(String param)
    {
        BpmUserInfo userinfo = null;
        ObjectMapper om = new ObjectMapper();
        try
        {
            userinfo = om.readValue(param, BpmUserInfo.class);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        
        Page page = zoneResourceService.queryToday(userinfo);
        return page;
    }
}

DAO层接口

import com.wulf.zoneresource.api.bean.Page;
import com.wulf.zoneresource.provider.bean.BpmUserInfo;

public interface ZoneResourceService {
    
    public Page queryToday(BpmUserInfo userinfo);
}

DAO层实现类就略过了

3、服务消费者控制类，提供http接口给外部调用，注入公共API

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.MediaType;

import org.springframework.beans.factory.annotation.Autowired;

import com.wulf.zoneresource.api.MobileZoneResourceService;
import com.wulf.zoneresource.api.bean.Page;

@Path("/hello/world")
@Produces({MediaType.APPLICATION_JSON})
public class MobileZoneResourceController
{
    @Autowired
    private MobileZoneResourceService mobileZoneResourceService;
    
    @GET
    @Path("/nihao.jsp")
    public Page queryToday(@QueryParam("param") String param)
    {
        return mobileZoneResourceService.queryToday(param);
    }
}    

4、web配置

消费者web.xml，使用resteasy作为web容器分发控制器

<web-app>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:META-INF/spring/consumer.xml</param-value>
    </context-param>

    <listener>
        <listener-class>com.alibaba.dubbo.remoting.http.servlet.BootstrapListener
        </listener-class>
    </listener>

    <listener>
        <listener-class>org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap
        </listener-class>
    </listener>
      
    <listener>
        <listener-class>org.jboss.resteasy.plugins.spring.SpringContextLoaderListener
        </listener-class>
    </listener>
     
    <servlet>
        <servlet-name>resteasy-servlet</servlet-name>
        <servlet-class>
            org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
        </servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>resteasy-servlet</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

提供者web.xml，使用dubbo作为web容器分发控制器

<web-app>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:META-INF/spring/provider.xml</param-value>
    </context-param>

    <listener>
        <listener-class>com.alibaba.dubbo.remoting.http.servlet.BootstrapListener
        </listener-class>
    </listener>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener
        </listener-class>
    </listener>

    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>com.alibaba.dubbo.remoting.http.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

5、dubbo配置

消费者，通过把控制器配置为bean来加载

<?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:dubbo="http://code.alibabatech.com/schema/dubbo"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
    http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:annotation-config />

    <!-- 消费方应用信息，用于计算依赖关系 -->
    <dubbo:application name="zr_consumer" />

    <dubbo:registry address="zookeeper://127.0.0.1:2181" />

    <!-- 消费者接口 -->
    <dubbo:reference id="mobileZoneResourceService"
        interface="com.wulf.zoneresource.api.MobileZoneResourceService" />

    <!-- 对外control -->
    <bean id="mobileZoneResourceController"
        class="com.wulf.zoneresource.consumer.control.MobileZoneResourceController" />

</beans>

提供者

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd 
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
       http://code.alibabatech.com/schema/dubbo
       http://code.alibabatech.com/schema/dubbo/dubbo.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <context:annotation-config />

    <!-- 提供方应用信息，用于计算依赖关系 -->
    <dubbo:application name="zr_provider" />

    <context:property-placeholder location="classpath:global.properties" />

    <!-- 使用zookeeper注册中心暴露服务地址 -->
    <dubbo:registry protocol="zookeeper" address="${zk.servers}" />

    <!-- 采用dubbox提供的REST风格服务(基于resteasy) -->
    <dubbo:protocol name="rest" server="servlet" port="${rest.server.port}" />

    <!-- timeout远程服务调用超时时间(毫秒)，适用所有服务 -->
    <!-- threads该服务线程池大小 ，适用所有服务 -->
    <!-- accepts限制服务器端接受的连接不能超过个数，适用所有服务 -->
    <dubbo:provider timeout="${timeout}" threads="${threads}"
        accepts="${accepts}" />

    <!-- 暴露服务接口 一个服务可以用多个协议暴露，一个服务也可以注册到多个注册中心 -->
    <dubbo:service interface="com.wulf.zoneresource.api.MobileZoneResourceService"
        ref="mobileZoneResourceService" />

    <!-- 和本地bean一样实现服务 -->
    <bean id="mobileZoneResourceService"
        class="com.wulf.zoneresource.provider.service.MobileZoneResourceServiceImpl" />

    <bean id="zoneResourceService"
        class="com.wulf.zoneresource.provider.dao.ZoneResourceServiceImpl" />

    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource" />
    </bean>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="${driver.class}" />
        <property name="url" value="${driver.url}" />
        <property name="username" value="${db.username}" />
        <property name="password" value="${db.password}" />
    </bean>

    <bean id="txManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
    </bean>
    <tx:annotation-driven transaction-manager="txManager" />
</beans>

global.properties

zk.servers=zookeeper://127.0.0.1:2181
rest.server.port=8098

timeout=5000
threads=100
accepts=1000

driver.class=oracle.jdbc.driver.OracleDriver
driver.url=jdbc:oracle:thin:@10.211.95.152:1521:testdba
db.username=ues
db.password=ues2017

　　消费者使用RESTEasy框架需要的maven依赖：

        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jaxrs</artifactId>
            <version>3.0.7.Final</version>
        </dependency>

        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-client</artifactId>
            <version>3.0.7.Final</version>
        </dependency>

        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-netty</artifactId>
            <version>3.0.7.Final</version>
        </dependency>

        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jdk-http</artifactId>
            <version>3.0.7.Final</version>
        </dependency>

        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jackson-provider</artifactId>
            <version>3.0.7.Final</version>
        </dependency>

        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jaxb-provider</artifactId>
            <version>3.0.7.Final</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-spring</artifactId>
            <version>3.0.7.Final</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-servlet-initializer</artifactId>
            <version>3.0.7.Final</version>
        </dependency>