spring3.2.2 remoting HTTP invoker 实现方式

最近跟朋友聊天，聊到他们现在项目的架构都是把数据层跟应用层分离开来，中间可以加memcached等的缓存系统，感觉挺好的，很大程度上的降低耦合，然后还明确分配了数据层跟应用层任务。也方便定位、找到问题。（我们都用最简单的架构，就没搞过分布式部署，小公司没办法o(︶︿︶)o），就找时间学习了，说不定以后就好应用上。这里用了 HTTP invoker方式，别的rmi或者jms等也大同小异。

这里我使用的是spring3.2.2，jar包就不列了，少哪个加哪个就可以了。

spring官方文档一共提供三种方式：通过Spring Web MVC，通过一个servlet指向跟不依赖web容器使用Sun's Java 6构建。我这里用的是第二种方式，别的官方文档讲解还是很清晰的，根据那个操作即可。

首先server端：

Model

model是需要序列化的才能remote传输

public class ServiceReso implements Serializable {
    private static final long serialVersionUID = 1L;
    private String id;
    private String serviceName;
    private String serviceAddress;

    public ServiceReso() {
        super();
    }

    public ServiceReso(String id, String serviceName, String serviceAddress) {
        super();
        this.id = id;
        this.serviceName = serviceName;
        this.serviceAddress = serviceAddress;
    }

    public final String getId() {
        return id;
    }

    public final void setId(String id) {
        this.id = id;
    }

    public final String getServiceName() {
        return serviceName;
    }

    public final void setServiceName(String serviceName) {
        this.serviceName = serviceName;
    }

    public final String getServiceAddress() {
        return serviceAddress;
    }

    public final void setServiceAddress(String serviceAddress) {
        this.serviceAddress = serviceAddress;
    }

    @Override
    public String toString() {
        return "{"id":"" + this.id + "","serviceName":""
                + this.serviceName + "","serviceAddress":""
                + this.serviceAddress + ""}";
    }
}

Dao

public interface ServiceResoDao {
    /**
     * 根据传入的id值返回ServiceReso对象
     * 
     * @param id
     *            需要查询的ServiceReso对象id
     * @return ServiceReso
     */
    public ServiceReso find(String id);
}

DaoImp

jdbc没有做持久化，采用了spring自带的JdbcTemplate，感觉还是挺好用的。 

@Repository("serviceResoDao")
public class ServiceResoDaoImp implements ServiceResoDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    public ServiceReso find(String id) {
        String sql = "select SERVERID,REALSERVERNAME,DSIPADDR from COSH_SERVICE_REGISTER where SERVERID=?";
        ServiceReso serviceReso = jdbcTemplate.queryForObject(sql,
                new Object[] { id }, new RowMapper<ServiceReso>() {
                    public ServiceReso mapRow(ResultSet rs, int rowNum)
                            throws SQLException {
                        ServiceReso serviceReso = new ServiceReso(rs
                                .getString("SERVERID"), rs
                                .getString("REALSERVERNAME"), rs
                                .getString("DSIPADDR"));
                        return serviceReso;
                    }
                });
        return serviceReso;
    }
}

beans.xml:

这里的urlMapping是用来分发不同的请求，免得在servlet中对应每个bean。

<?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:context="http://www.springframework.org/schema/context"
    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.blackbread" />
    <bean
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <value>classpath:jdbc.properties</value>
        </property>
    </bean>
    <bean id="springDSN"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName"
            value="${jdbc.driverClassName}">
        </property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>
    <bean id="jdbcTemplate"
        class="org.springframework.jdbc.core.JdbcTemplate" abstract="false"
        lazy-init="false" autowire="default">
        <property name="dataSource">
            <ref bean="springDSN" />
        </property>
    </bean>
    <bean name="serviceResoDaoRemoting"
        class="org.springframework.remoting.httpinvoker.HttpInvokerServiceExporter">
        <property name="service" ref="serviceResoDao" />
        <property name="serviceInterface"
            value="com.blackbread.dao.ServiceResoDao" />
    </bean>
    <bean name="urlMapping"
        class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="mappings">
            <props>
                <prop key="/serviceResoDaoRemoting">
                    serviceResoDaoRemoting
                </prop>
            </props>
        </property>
    </bean>
</beans>

web.xml

这里有个问题：servlet-mapping中的url-pattern如果不是这样写，而是改成/remoting/*之类的就会请求不到资源，望知道的兄弟告知下，不胜感激。

<?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">
    <servlet>
        <servlet-name>dispatcherServlet</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath*:beans.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

 client端：

client需要将server端的接口类跟实体类打包成jar，加以引用。

service

public interface ServiceResoService {
    void getServiceReso(String id);
}

serviceImp

@Controller("serviceResoService")
public class ServiceResoServiceImp implements ServiceResoService {
    @Resource(name = "serviceResoDaoReomting")
    ServiceResoDao serviceResoDao;

    public void getServiceReso(String id) {
        ServiceReso serviceReso;
        try {
            serviceReso = serviceResoDao.find(id);
            System.out.println(serviceReso.toString());
        } catch (RuntimeException e) {
            System.out.println("未找到结果！");
        }

    }

}

beans.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:context="http://www.springframework.org/schema/context"
    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.blackbread" />
    <bean id="serviceResoDaoReomting"
        class="org.springframework.remoting.httpinvoker.HttpInvokerProxyFactoryBean">
        <property name="serviceUrl"
            value="http://localhost:8080/HttpInvokerDAO/serviceResoDaoRemoting" />
        <property name="serviceInterface"
            value="com.blackbread.dao.ServiceResoDao" />
    </bean>
</beans>

web.xml

<?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">
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    <listener>
        <listener-class>
            org.springframework.web.context.ContextLoaderListener
        </listener-class>
    </listener>
    <!-- 设置Spring容器加载配置文件路径 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath*:beans.xml</param-value>
    </context-param>
</web-app>