dubbo實踐2--引用dubbo服務

   上篇講解了如何發佈一個dubbo服務，這節講解web工程如何引用dubbo發佈的服務。

         首先我們在web工程也需要添加dubbo的依賴，由於我們在taotao-manager-service工程已經添加了dubbo的依賴並且解決了包衝突的問題，那麼我們便可以直接把taotao-manager-service工程下的關於dubbo的依賴部分拷貝過來，拷貝的內容如下：

<!-- dubbo相關的jar包 -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>dubbo</artifactId>
        <exclusions>
            <exclusion>
                <artifactId>spring</artifactId>
                <groupId>org.springframework</groupId>
            </exclusion>
            <exclusion>
                <artifactId>netty</artifactId>
                <groupId>org.jboss.netty</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.apache.zookeeper</groupId>
        <artifactId>zookeeper</artifactId>
    </dependency>
    <dependency>
        <groupId>com.github.sgroschupf</groupId>
        <artifactId>zkclient</artifactId>
    </dependency>

         拷貝後的taotao-manager-web工程的pom.xml文件的內容如下：

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.taotao</groupId>
    <artifactId>taotao-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <groupId>com.taotao</groupId>
  <artifactId>taotao-manager-web</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>

  <dependencies>
    <!-- 依賴taotao-common -->
    <dependency>
        <groupId>com.taotao</groupId>
        <artifactId>taotao-common</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
    <!-- Spring -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jms</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
    </dependency>
    <!-- JSP相關 -->
    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jsp-api</artifactId>
        <scope>provided</scope>
    </dependency>
    <!-- dubbo相關的jar包 -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>dubbo</artifactId>
        <exclusions>
            <exclusion>
                <artifactId>spring</artifactId>
                <groupId>org.springframework</groupId>
            </exclusion>
            <exclusion>
                <artifactId>netty</artifactId>
                <groupId>org.jboss.netty</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.apache.zookeeper</groupId>
        <artifactId>zookeeper</artifactId>
    </dependency>
    <dependency>
        <groupId>com.github.sgroschupf</groupId>
        <artifactId>zkclient</artifactId>
    </dependency>
  </dependencies>
  <build>
    <plugins>
        <plugin>
            <groupId>org.apache.tomcat.maven</groupId>
            <artifactId>tomcat7-maven-plugin</artifactId>
            <configuration>
                <path>/</path>
                <port>8081</port>
            </configuration>
        </plugin>
    </plugins>
  </build>
</project>

       下面我們需要在taotao-manager-web工程下的springmvc.xml文件中引用dubbo服務，添加的內容如下。其中<dubbo:application name="taotao-manager-web"/>是要在註冊中心申報一下名字，名字不能衝突。<dubbo:registry protocol="zookeeper" address="192.168.25.167:2181"/>同服務端一樣，在註冊中心註冊下dubbo服務所在的IP及端口。<dubbo:reference interface="com.taotao.service.ItemService" id="itemService" />便是要引用服務端的接口了。

<!-- 引用dubbo服務 -->
    <dubbo:application name="taotao-manager-web"/>
    <dubbo:registry protocol="zookeeper" address="192.168.25.167:2181"/>
    <dubbo:reference interface="com.taotao.service.ItemService" id="itemService" />

      引用dubbo服務之後springmvc的完整內容如下：

<?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:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.2.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-4.2.xsd">

    <!-- 配置註解驅動 -->
    <mvc:annotation-driven />
    <!-- 視圖解析器 -->
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
    <!-- 配置包掃描器，掃描@Controller註解的類 -->
    <context:component-scan base-package="com.taotao.controller"/>

    <!-- 引用dubbo服務 -->
    <dubbo:application name="taotao-manager-web"/>
    <dubbo:registry protocol="zookeeper" address="192.168.25.167:2181"/>
    <dubbo:reference interface="com.taotao.service.ItemService" id="itemService" />
</beans>

      由於taotao-manager-web工程與taotao-mananger-interface是獨立的兩個工程，因此要在taotao-manager-web工程中要添加對taotao-manager-interface的依賴，添加的內容如下：

<dependency>
        <groupId>com.taotao</groupId>
        <artifactId>taotao-manager-interface</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>

       添加後當前taotao-manager-web工程的pom.xml文件全部內容如下：

<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/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.taotao</groupId>
    <artifactId>taotao-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <groupId>com.taotao</groupId>
  <artifactId>taotao-manager-web</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>war</packaging>

  <dependencies>
    <!-- 依賴taotao-common -->
    <dependency>
        <groupId>com.taotao</groupId>
        <artifactId>taotao-common</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>com.taotao</groupId>
        <artifactId>taotao-manager-interface</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>
    <!-- Spring -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jms</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
    </dependency>
    <!-- JSP相關 -->
    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jsp-api</artifactId>
        <scope>provided</scope>
    </dependency>
    <!-- dubbo相關的jar包 -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>dubbo</artifactId>
        <exclusions>
            <exclusion>
                <artifactId>spring</artifactId>
                <groupId>org.springframework</groupId>
            </exclusion>
            <exclusion>
                <artifactId>netty</artifactId>
                <groupId>org.jboss.netty</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.apache.zookeeper</groupId>
        <artifactId>zookeeper</artifactId>
    </dependency>
    <dependency>
        <groupId>com.github.sgroschupf</groupId>
        <artifactId>zkclient</artifactId>
    </dependency>
  </dependencies>
  <build>
    <plugins>
        <plugin>
            <groupId>org.apache.tomcat.maven</groupId>
            <artifactId>tomcat7-maven-plugin</artifactId>
            <configuration>
                <path>/</path>
                <port>8081</port>
            </configuration>
        </plugin>
    </plugins>
  </build>
</project>

        maven更新完之後，我們可以在taotao-manager-web工程所依賴的包中找到taotao-manager-interface，如下圖所示。

       添加完對taotao-manager-interface的依賴後，我們便可以直接使用它了。

        如果我們使用@ResponseBody註解後訪問的時候報406錯誤（無法把對象轉換爲json串），90%是可能沒有引入jackson包，我們到"Maven Dependencies"下查看是否有如下圖所示的三個包。

        如果沒有，那麼我們需要在taotao-common工程的pom.xml文件中引入jackson的依賴，由於我們的taotao-mananger-web工程依賴了taotao-common，因此它會自動依賴jackson包。現在我們的taotao-common中是依賴了jackson的，因此我們不用做任何處理。

<!-- Jackson Json處理工具包 -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>

       到此，我們的SSM框架整合便整合完了。