Dubbo在SSM项目中的使用
案例源代码下载地址
https://download.csdn.net/download/pcbhyy/10764704
操作步骤
- 创建一个ssm集成的项目,及编写初始代码
- 把该项目拆分为两部分(表示层一部分、业务逻辑和数据访问层一部分)
- 通过dubbo在表示层中访问业务逻辑层中的组件(关键)
Dubbo简介
Dubbo是阿里巴巴公司开源的一个高性能优秀的服务框架,使得应用可通过高性能的 RPC 实现
服务的输出和输入功能,可以和Spring框架无缝集成。
- Provider
暴露服务方称之为“服务提供者”。 - Consumer
调用远程服务方称之为“服务消费者”。 - Registry
服务注册与发现的中心目录服务称之为“服务注册中心”。 - Monitor
统计服务的调用次数和调用时间的日志服务称之为“服务监控中心”。
一、项目拆分
- 拆分内容:
web.xml
pom.xml
springmvc.xml
applicationContext.xml
部分配置文件的删除
代码的删减 - 表示层项目
1)pom.xml(注意:添加了dubbo、zookeeper的依赖)
<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.yy</groupId>
<artifactId>ssm_dept2_vc</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
<resource>
<directory>src/main/resources</directory>
</resource>
</resources>
<plugins>
<!-- 资源文件拷贝插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.7</version>
<configuration>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<!-- java编译插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
<configuration>
<!-- 部署路径,如:/e3mall,表明部署到/e3mall路径下 -->
<path>/</path>
<!-- 端口号 -->
<port>8090</port>
<uriEncoding>utf-8</uriEncoding>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>aopalliance</groupId>
<artifactId>aopalliance</artifactId>
<version>1.0</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.10</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.2.2</version>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/javax.servlet.jsp/jsp-api -->
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.2</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<!--解决Spring使用slf4j输出日志与log4j冲突的问题 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.25</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>5.4.1.Final</version>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>1.1.0.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jboss.logging/jboss-logging -->
<dependency>
<groupId>org.jboss.logging</groupId>
<artifactId>jboss-logging</artifactId>
<version>3.3.1.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml/classmate -->
<dependency>
<groupId>com.fasterxml</groupId>
<artifactId>classmate</artifactId>
<version>1.3.3</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.8.8.1</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.0.0</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.5.3</version>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.7</version>
</dependency>
<dependency>
<groupId>com.github.sgroschupf</groupId>
<artifactId>zkclient</artifactId>
<version>0.1</version>
</dependency>
</dependencies>
</project>
2)web.xml(注意:去掉了监听器和上下文参数)
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<display-name>spring_demo</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<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>
<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:springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
3)去掉了applicationContext.xml、db.properties、SqlMapConfig.xml三个配置文件
4)删除了com.yy.mapper包和com.yy.service包中的实现类(接口留着)
3. 业务逻辑和数据访问层项目
1)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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.yy</groupId>
<artifactId>ssm_dept2_m</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
<resource>
<directory>src/main/resources</directory>
</resource>
</resources>
<plugins>
<!-- 资源文件拷贝插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.7</version>
<configuration>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<!-- java编译插件 -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
<configuration>
<!-- 部署路径,如:/e3mall,表明部署到/e3mall路径下 -->
<path>/</path>
<!-- 端口号 -->
<port>8089</port>
<uriEncoding>utf-8</uriEncoding>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>aopalliance</groupId>
<artifactId>aopalliance</artifactId>
<version>1.0</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.10</version>
</dependency>
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.6</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.2.6</version>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>3.2.5</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.2.2</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.8.RELEASE</version>
</dependency>
<!--解决Spring使用slf4j输出日志与log4j冲突的问题 -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.25</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>5.4.1.Final</version>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>1.1.0.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.jboss.logging/jboss-logging -->
<dependency>
<groupId>org.jboss.logging</groupId>
<artifactId>jboss-logging</artifactId>
<version>3.3.1.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.fasterxml/classmate -->
<dependency>
<groupId>com.fasterxml</groupId>
<artifactId>classmate</artifactId>
<version>1.3.3</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.0.0</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>2.5.3</version>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.7</version>
</dependency>
<dependency>
<groupId>com.github.sgroschupf</groupId>
<artifactId>zkclient</artifactId>
<version>0.1</version>
</dependency>
</dependencies>
</project>
- web.xml(删除了前端控制器Servlet的配置)
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
<display-name>spring_demo</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<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>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
</web-app>
3)删除了springmvc.xml
4)删除了com.yy.controller包和所有jsp页面
二、在linux中安装zookeeper
1)测试java环境
java -version
2)SSH上传提示:encountered 1 errors during the transfer错误解决办法
上传的时候 windows 的路径不能存在括号“()”, 把括号去掉 重新上传就好了 或
把文件移到不带小括号的路径下就可以正常上传文件了。
3)zookeeper是java开发的可以运行在windows、linux环境。需要先安装jdk。
安装步骤:
第一步:安装jdk
第二步:把zookeeper的压缩包上传到linux系统。
第三步:解压缩压缩包
tar -zxvf zookeeper-3.4.6.tar.gz
第四步:进入zookeeper-3.4.6目录,创建data文件夹。
mkdir data
第五步:进入conf文件夹,把zoo_sample.cfg改名为zoo.cfg
[root@localhost conf]# mv zoo_sample.cfg zoo.cfg
第六步:编辑 zoo.cfg(vim zoo.cfg),修改data属性:dataDir=/root/zookeeper-3.4.6/data
第七步:启动zookeeper
[root@localhost bin]# ./zkServer.sh start
关闭:
[root@localhost bin]# ./zkServer.sh stop
查看状态:
[root@localhost bin]# ./zkServer.sh status
成功启动显示如下内容:
JMX enabled by default
Using config: /root/zookeeper-3.4.6/bin/../conf/zoo.cfg
Mode: standalone
注意:需要关闭防火墙。
service iptables stop
永久关闭修改配置开机不启动防火墙:
chkconfig iptables off
如果不能成功启动zookeeper,需要删除data目录下的zookeeper_server.pid文件。
三、通过dubbo在表示层中访问业务逻辑层中的组件
- 业务逻辑项目中发布组件(在applicationContext.xml中添加)
<!-- 使用dubbo发布服务 -->
<dubbo:application name="ssm_dept2_m"/>
<!-- address为虚拟机zookeeper地址及端口号,集群时候可以配置多个地址 -->
<dubbo:registry protocol="zookeeper" address="192.168.220.129:2181"></dubbo:registry>
<!-- 用dubbo协议在20880端口暴露服务 -->
<dubbo:protocol name="dubbo" port="20880" />
<!-- 声明需要暴露的接口,ref为该接口的实现类,为自动扫描到的组件 -->
<dubbo:service interface="com.yy.service.DeptService" ref="deptServiceImpl"></dubbo:service>
<dubbo:service interface="com.yy.service.EmpService" ref="empServiceImpl"></dubbo:service>
- 在表示层项目中引用组件(在springmvc.xml中添加)
<!-- 引用dubbo服务-->
<!-- name为当前项目名即可 -->
<dubbo:application name="ssm_dept2_vc"/>
<dubbo:registry protocol="zookeeper" address="192.168.220.129:2181"></dubbo:registry>
<!-- id相当于引用后为引用bean起的id -->
<dubbo:reference interface="com.yy.service.DeptService" id="deptService"></dubbo:reference>
<dubbo:reference interface="com.yy.service.EmpService" id="empService"></dubbo:reference>
- 先启动业务逻辑项目,在启动表示层项目(注意:修改两个项目中tomcat的端口号不相同)
- 在浏览器中访问action,测试
四、说明
Dubbo是什么?
Dubbo是一个分布式服务框架,致力于提供高性能和透明化的RPC远程服务调用方案,以及SOA服务治理方案。简单的说,dubbo就是个服务框架,如果没有分布式的需求,其实是不需要用的,只有在分布式的时候,才有dubbo这
样的分布式服务框架的需求,并且本质上是个服务调用的东东,说白了就是个远程服务调用的分布式框架(告别Web Service模式中的WSdl,以服务者与消费者的方式在dubbo上注册)
其核心部分包含:
- 远程通讯: 提供对多种基于长连接的NIO框架抽象封装,包括多种线程模型,序列化,以及“请求-响应”模式的信息交换方式。
- 集群容错: 提供基于接口方法的透明远程过程调用,包括多协议支持,以及软负载均衡,失败容错,地址路由,动态配置等集群支持。
- 自动发现: 基于注册中心目录服务,使服务消费方能动态的查找服务提供方,使地址透明,使服务提供方可以平滑增加或减少机器。
Dubbo能做什么?
- 透明化的远程方法调用,就像调用本地方法一样调用远程方法,只需简单配置,没有任何API侵入。
- 软负载均衡及容错机制,可在内网替代F5等硬件负载均衡器,降低成本,减少单点。
- 服务自动注册与发现,不再需要写死服务提供方地址,注册中心基于接口名查询服务提供者的IP地址,并且能够平滑添加或删除服务提供者。