关于dubbo改造ssm项目的一些总结

1.首先建立四个maven项目

dubbo-parent为父项目,打包方式为pom
在pom.xml文件中导入相关的依赖
dubbo-parent/pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>
  <groupId>com.wuhongyu</groupId>
  <artifactId>dubbo-parent</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>

  <!-- 设置spring的版本,以及项目的编码格式 -->
    <properties>
        <spring.version>5.0.4.RELEASE</spring.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>
  <dependencies>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.0.1</version>
            <scope>provided</scope>
        </dependency>


        <!-- https://mvnrepository.com/artifact/junit/junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!-- spring的aop的jar包 -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.6.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/aopalliance/aopalliance -->
        <dependency>
            <groupId>aopalliance</groupId>
            <artifactId>aopalliance</artifactId>
            <version>1.0</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/cglib/cglib -->
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>3.2.6</version>
        </dependency>

        <!-- common工具的jar包 -->
        <dependency>
            <groupId>commons-pool</groupId>
            <artifactId>commons-pool</artifactId>
            <version>1.6</version>
        </dependency>
        <dependency>
            <groupId>commons-beanutils</groupId>
            <artifactId>commons-beanutils</artifactId>
            <version>1.9.2</version>
        </dependency>
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>commons-codec</groupId>
            <artifactId>commons-codec</artifactId>
            <version>1.9</version>
        </dependency>

        <!-- 日志的jar包 -->

        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.11.0</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.12</version>
        </dependency>
        <!-- mybatis的jar包和mybatisspring整合的jar包 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.2.8</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.2</version>
        </dependency>
        <!-- spring 和spring mvc -->

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet.jsp.jstl/jstl -->
        <!-- jstl -->
        <!-- https://mvnrepository.com/artifact/taglibs/standard -->
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp.jstl</groupId>
            <artifactId>jstl-api</artifactId>
            <version>1.2</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.servlet</groupId>
                    <artifactId>servlet-api</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.servlet.jsp</groupId>
                    <artifactId>jsp-api</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- json -->
        <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.4</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/org.javassist/javassist -->
        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.22.0-GA</version>
        </dependency>
        <!-- mysql驱动 -->
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.24</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper -->
    <dependency>
        <groupId>com.github.pagehelper</groupId>
        <artifactId>pagehelper</artifactId>
        <version>5.1.2</version>
    </dependency>
        <!-- https://mvnrepository.com/artifact/org.freemarker/freemarker -->
    <dependency>
        <groupId>org.freemarker</groupId>
        <artifactId>freemarker</artifactId>
        <version>2.3.28</version>
    </dependency>
    <dependency>
      <groupId>org.apache.zookeeper</groupId>
      <artifactId>zookeeper</artifactId>
      <version>3.4.9</version>
    </dependency>
    <!-- dubbo -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>dubbo</artifactId>
      <version>2.5.3</version>
      <exclusions>
        <exclusion>
          <groupId>org.springframework</groupId>
          <artifactId>spring</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>com.101tec</groupId>
      <artifactId>zkclient</artifactId>
      <version>0.10</version>
    </dependency>

    </dependencies>
  <modules>
    <module>dubbo-api</module>
    <module>dubbo-server</module>
    <module>dubbo-web</module>
  </modules>
</project>

dubbo-api为接口和实体类 打包方式为jar
目录结构为

这里有一些坑:
1.因为dubbo实际上是通过序列化和反序列化实现的,所以实体类的对象必须实现序列化接口,实体类对象的子类(如果有的话)也需要添加版本号.
2.如果实体类中有时间类型(Date),一定要写java.util.Date,如果写java.sql.Date消费层像服务层传对象的时候会出现NullPointException的异常
User.java的代码:

package com.wuhongyu.entity;

import java.io.Serializable;

public class User implements Serializable{
    /**
     * 
     */
    private static final long serialVersionUID = -5584068694070223356L;

    private Long id;

    private String username;

    private String password;

    public Long getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username == null ? null : username.trim();
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password == null ? null : password.trim();
    }
}

UserService接口代码

package com.wuhongyu.service;

import java.util.List;

import com.wuhongyu.entity.User;

public interface UserService {

    public List<User> selectAll();
}

dubbo-server为dubbo的服务者,提供接口的实现类给消费者(dubbo-web)使用,打包方式为war
目录结构
这里的报错是eclipse校验xml文件的问题,对项目运行没有影响

要将上一步配置的dubbo-api作为依赖引入dubbo-server
dubbo-server/pom.xml配置如下:

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.wuhongyu</groupId>
    <artifactId>dubbo-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <groupId>com.wuhongyu</groupId>
  <artifactId>dubbo-server</artifactId>
  <version>1.0</version>
  <packaging>war</packaging>
  <name>dubbo-server Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>com.wuhongyu</groupId>
      <artifactId>dubbo-api</artifactId>
      <version>1.0</version>
    </dependency>
  </dependencies>
  <build>
    <finalName>dubbo-server</finalName>
  </build>
</project>

UserMapper.java和UserMapper.xml为MyBatis逆向工程自动生成的文件
UserServiceImpl为UserService的实现类
注意:
本项目中PageHelper不能在dubbo-web的conrtoller层使用,如果使用分页会失效
所以我在dubbo-server里的mapper之前使用来完成分页

package com.wuhongyu.service.impl;

import java.util.List;

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

import com.github.pagehelper.PageHelper;
import com.wuhongyu.entity.User;
import com.wuhongyu.entity.UserExample;
import com.wuhongyu.mapper.UserMapper;
import com.wuhongyu.service.UserService;

@Service("userService")
public class UserServiceImpl implements UserService{

    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> selectAll() {
        UserExample example = new UserExample();
        example.createCriteria();
        PageHelper.startPage(1, 3);
        List<User> userList = userMapper.selectByExample(example);
        return userList;
    }



}

spring和dubbo的配置文件:
applicationContext-dubbo.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:dubbo="http://code.alibabatech.com/schema/dubbo"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://code.alibabatech.com/schema/dubbo
       http://code.alibabatech.com/schema/dubbo/dubbo.xsd">

    <dubbo:application name="dubbo-server"/>


    <dubbo:registry address="zookeeper://localhost:2181" />
    <!-- 用dubbo协议在20880端口暴露服务 -->
    <dubbo:protocol name="dubbo" port="20880" />

    <dubbo:service interface="com.wuhongyu.service.UserService"
        ref="userService" protocol="dubbo" />
</beans>

spring的配置文件applicationContext-spring.xml
该文件没有改动,直接从ssm项目中copy过来

<?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:aop="http://www.springframework.org/schema/aop"
    xmlns:tx="http://www.springframework.org/schema/tx"
    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://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd"
    default-autowire="byName">
    <!-- 注解扫描, service.impl -->
    <context:component-scan base-package="com.wuhongyu.service.impl" />
    <!-- properties文件加载 -->
    <!-- 数据源 -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/test" />
        <property name="username" value="root" />
        <property name="password" value="root" />
    </bean>
    <!-- sqlSessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 数据库连接池 -->
        <property name="dataSource" ref="dataSource" />
        <!-- 自动扫描mapping.xml文件 -->
        <property name="mapperLocations" value="classpath:com/wuhongyu/mapper/*.xml"></property>
        <!-- 配置分页插件 -->
        <property name="plugins">
           <array>
             <bean class="com.github.pagehelper.PageInterceptor">
               <property name="properties">
                 <value>
                   helperDialect=mysql
                 </value>
               </property>
             </bean>
           </array>
         </property>
    </bean>
    <!-- mapper扫描器 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.wuhongyu.mapper" />
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
    </bean>
    <!-- 事务管理器 -->
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager" />
    <!-- 声明式事务 -->
    <tx:advice id="txAdvice" transaction-manager="txManager">
        <tx:attributes>
            <tx:method name="ins*" />
            <tx:method name="upd*" />
            <tx:method name="del*" />
            <!-- <tx:method name="*" read-only="true" /> -->
        </tx:attributes>
    </tx:advice>
    <!-- AOP -->
    <aop:config>
        <aop:pointcut expression="execution(* com.wuhongyu.service.impl.*.*(..))" id="pt"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="pt" />
    </aop:config>
    <aop:aspectj-autoproxy  proxy-target-class="true"/>

</beans>

我是在tomcat中启动的程序,所以要配置web.xml,web.xml只需要加载spring配置文件即可
其实这里的服务端也可以用一个main方法来加载spring的配置文件来启动该项目
web.xml配置:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    version="3.1">

    <!-- 加载spring容器 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:spring/applicationContext*.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>


</web-app>

打开zookeeper
运行zookeeper的bin目录下面的zkServer.cmd
如果出现cmd一闪的情况,原因是环境变量里没有配置java的CLASSPATH
百度配置java环境变量配置完成即可

把dubbo-server项目部署到tomcat下启动
注意:
最好多弄几个tomcat服务器,可以自行百度如何启动多个tomcat

启动成功后打开zookeeper服务监控中心,UserService服务已经发布出来

接下来编写dubbo-web(消费者端)
dubbo-web结构如下:

同样,dubbo-web也需要引入dubbo-api依赖
dubbo-web/pom.xml

<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>com.wuhongyu</groupId>
    <artifactId>dubbo-parent</artifactId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <groupId>com.wuhongyu</groupId>
  <artifactId>dubbo-web</artifactId>
  <version>1.0</version>
  <packaging>war</packaging>
  <name>dubbo-web Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupId>com.wuhongyu</groupId>
      <artifactId>dubbo-api</artifactId>
      <version>1.0</version>
    </dependency>
  </dependencies>
  <build>
    <finalName>dubbo-web</finalName>
  </build>
</project>

消费者dubbo的配置文件springmvc-dubbo.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:dubbo="http://code.alibabatech.com/schema/dubbo"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    <dubbo:application name="dubbo-web"/>
    <!--向 zookeeper 订阅 provider 的地址，由 zookeeper 定时推送-->
    <dubbo:registry address="zookeeper://localhost:2181"/>
    <!--使用 dubbo 协议调用定义好的 api.PermissionService 接口-->
    <dubbo:reference id="userService" interface="com.wuhongyu.service.UserService"/>

</beans>

springmvc的配置文件springmvc.xml
文件上传对于本项目来说可以删掉

<?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:mvc="http://www.springframework.org/schema/mvc"
    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/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- 可以扫描controller、service、... 这里让扫描controller，指定controller的包 -->
    <context:component-scan base-package="com.wuhongyu.controller"></context:component-scan>
    <!-- 注解驱动 -->
    <mvc:annotation-driven/>
    <!-- 文件上传 -->
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 设置上传文件的最大尺寸为5MB -->
        <property name="maxUploadSize">
            <value>5242880</value>
        </property>
    </bean>


    <!-- 自定义视图解析器 -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/" />
        <property name="suffix" value=".jsp" />
    </bean>

</beans>

编写UserController

package com.wuhongyu.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import com.github.pagehelper.PageInfo;
import com.wuhongyu.entity.User;
import com.wuhongyu.service.UserService;

@Controller
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/userList")
    @ResponseBody
    public List<User> userList() {
        List<User> userList = userService.selectAll();
        PageInfo<User> page = new  PageInfo<User>(userList);
        return userList;
    }

}

dubbo-web也需要在tomcat服务器上启动所以,配置web.xml
web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    version="3.1">
    <!-- post乱码过虑器 -->
    <filter>
        <filter-name>CharacterEncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>CharacterEncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>


    <!-- springmvc前端控制器 -->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <!-- contextConfigLocation配置springmvc加载的配置文件（配置处理器映射器、适配器等等） 如果不配置contextConfigLocation，默认加载的是/WEB-INF/servlet名称-serlvet.xml（springmvc-servlet.xml） -->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring/springmvc*.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <!-- 第一种：*.action，访问以.action结尾 由DispatcherServlet进行解析 第二种：/，所以访问的地址都由DispatcherServlet进行解析，对于静态文件的解析需要配置不让DispatcherServlet进行解析 
            使用此种方式可以实现 RESTful风格的url 第三种：/*，这样配置不对，使用这种配置，最终要转发到一个jsp页面时， 仍然会由DispatcherServlet解析jsp地址，不能根据jsp页面找到handler，会报错。 -->
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!-- 静态资源 -->
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.js</url-pattern>
        <url-pattern>*.css</url-pattern>
        <url-pattern>*.html</url-pattern>
        <url-pattern>/images/*</url-pattern>
    </servlet-mapping>


    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
    </welcome-file-list>
</web-app>

到此,配置完成,在另一台tomcat上部署dubbo-web

部署成功后输入地址
项目运行成功

项目源码地址:
https://github.com/ruanruanBlue/dubbo-parent
如果有什么问题欢迎提问和指出