9.OSGI企业应用开发-整合Spring和Mybatis框架(二)

- 日理万妓 2022-10-26 12:56 204阅读 0赞

上篇文章中，我们完成了在OSGI应用中整合Spring和Mybatis框架的准备工作，本节我们继续Spring和Mybatis框架的整合。

# 一、解决OSGI整合Spring中的Placeholder问题 #

使用Spring框架的朋友应该都知道，我们可以在Bean的配置文件中，使用$\{key\}的形式访问properties文件中对应的value值，需要用到Spring中的PropertyPlaceholderConfigurer类，使用方式如下，首先需要配置placeholder，例如：

<bean id="placeholder"class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
       <property name="location">
         <value>conf/jdbc.properties</value>
       </property>
    </bean>

conf/jdbc.properties文件内容如下：

jdbc.driverClassName=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost/mysqldb?useUnicode=true&characterEncoding=UTF-8&
    jdbc.username=root
    jdbc.password=123456

然后我们定义Bean的时候，就可以使用$\{key\}的方式访问jdbc.properties文件中的内容，例如：

<bean id="dataSource"class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close">
      <property name="driverClassName"value="${jdbc.driverClassName}" />
      <property name="url" value="${jdbc.url}" />
      <property name="username" value="${jdbc.username}"/>
      <property name="password"value="${jdbc.password}" />
    </bean>1

但是在OSGI应用中，并没有全局的Classpath的概念，其中一个Bundle的属性文件在其他Bundle中无法访问，而且不同Bundle中的ApplictionContext也是独立的，PropertyPlaceholderConfigurer实例在不同的Bundle中不是共享的，所以Spring框架中的Placeholder配置也就存在一定的问题。

Gemini Blueprint为OSGI应用中使用Placeholder提供了一种解决方案，但是基于Key-Value的配置信息需要定义在XML文件中，例如：

：

<?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:osgix="http://www.springframework.org/schema/osgi-compendium"
       xmlns:ctx="http://www.springframework.org/schema/context"
       xmlns:osgi="http://www.eclipse.org/gemini/blueprint/schema/blueprint"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans 
          http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context 
          http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/osgi-compendium 
          http://www.springframework.org/schema/osgi-compendium/spring-osgi-compendium.xsd
          http://www.eclipse.org/gemini/blueprint/schema/blueprint 
           http://www.eclipse.org/gemini/blueprint/schema/blueprint/gemini-blueprint.xsd">
    
       <osgix:cm-properties id="dbInfo" persistent-id="com.csdn.osgi.common">
          <prop key="driver">com.mysql.jdbc.Driver</prop>
          <prop key="url">jdbc:mysql://127.0.0.1:3306/osgi</prop>
          <prop key="username">root</prop>
          <prop key="password"></prop>
       </osgix:cm-properties>
    
       <ctx:property-placeholder properties-ref="dbInfo" />
    
    </beans>

接下来在Bean的定义中，就可以一$\{Key\}的形式访问Value值了，例如：

# 二、Spring与Mybatis框架整合 #

1、首先新建一个Plug-in Project,名称为com.csdn.osgi.database，该Bundle用于操作数据库。

2、接着在com.csdn.osgi.database工程中新建META-INF/spring目录，然后在该目录下新建database.xml文件，用于配置数据源及Mybatis-Spring插件提供的SqlSessionFactoryBean和SqlSessionTemplate的实例，以及事务管理器等。  
database.xml文件内容如下：

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    
    
        <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">         
            <property name="driverClassName" value="${driver}" />  
            <property name="url" value="${url}" />  
            <property name="username" value="${username}" />     
            <property name="password" value="${password}" />        
        </bean>   
    
        <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> 
          <property name="dataSource" ref="dataSource" /> 
          <property name="configLocation" value="classpath:sqlMap.xml"/>
        </bean>
    
        
        <bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate"> 
          <constructor-arg index="0" ref="sqlSessionFactory" /> 
        </bean>
    
        
        <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">  
            <property name="dataSource" ref="dataSource" />  
        </bean> 
    
          
        <bean id="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">  
            <property name="transactionManager">  
                <ref local="transactionManager" />  
            </property>  
              
            <property name="isolationLevelName" value="ISOLATION_DEFAULT"/>  
            <property name="propagationBehaviorName" value="PROPAGATION_REQUIRED"/>
        </bean>  
    </beans>

3、接下来在META-INF/spring目录下，新建一个dmconfig.xml文件，用于配置placeholder及注册sqlSessionTemplate这个Bean，这样在其他Bundle中就可以通过引用我们注册的sqlSessionTemplate来操作数据库了。  
dmconfig.xml文件内容如下：

4、接下来就是Mybatis主配置文件和SQL的配置了，在sqlSessionFactory这个Bean的配置中，我们指定了Mybatis配置文件为sqlMap.xml，如下：

所以需要在com.csdn.osgi.database工程的src目录下新建一个sqlMap.xml文件，内容如下：

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>
        <mappers>
            <mapper resource="user.xml"/>
        </mappers>
    </configuration>

上面配置中，我们指定了SQL配置文件为user.xml，接着在com.csdn.osgi.database工程的src目录下新建user.xml文件，内容如下：

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper
    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="user">
        <insert id="saveUser" parameterType="java.util.HashMap">
            insert into user(username,password) values(#{UserName},#{Password});
        </insert>
    
        <select id="getPasswordByName" parameterType="java.lang.String" resultType="java.lang.String">
            select password from user where username = #{UserName}
        </select>
    </mapper>

5、整个工程目录及文件结构如下图所示：  
![这里写图片描述][SouthEast]  
6、然后还需要对com.csdn.osgi.database工程的MANIFEST.MF文件新建修改，添加如下Bundle的依赖：

Manifest-Version: 1.0
    Bundle-ManifestVersion: 2
    Bundle-Name: Database
    Bundle-SymbolicName: com.csdn.osgi.database
    Bundle-Version: 1.0.0.qualifier
    Bundle-Vendor: CSDN
    Bundle-RequiredExecutionEnvironment: JavaSE-1.8
    Require-Bundle: org.springframework.jdbc;bundle-version="3.0.0",
     org.mybatis.mybatis;bundle-version="3.1.1",
     com.springsource.org.apache.commons.dbcp;bundle-version="1.2.2",
     com.springsource.org.apache.commons.pool;bundle-version="1.3.0",
     org.springframework.transaction;bundle-version="3.0.0",
     com.springsource.com.mysql.jdbc;bundle-version="5.1.6",
     org.mybatis.mybatis-spring;bundle-version="1.2.3"

上面MANIFEST.MF文件中，Require-Bundle元数据头为新增。

7、最后一步，启动OSGI容器。需要单击Run=>Debug Configurations…菜单，如下图所示：  
![这里写图片描述][SouthEast 1]

单击Validate Bundles按钮，查看是否存在Bundle依赖问题，笔者单击后如下图所示：  
![这里写图片描述][SouthEast 2]

说明存在依赖问题，解决方法非常简单，单击面板上的Add Required Bundles按钮即可。

启动后输出控制台输出日志内容如下：

一月 07, 2017 3:40:33 下午 org.eclipse.gemini.blueprint.extender.internal.boot.ChainActivator <init>
    信息: Blueprint API detected; enabling Blueprint Container functionality
    一月 07, 2017 3:40:33 下午 org.eclipse.gemini.blueprint.extender.internal.activator.LoggingActivator start
    信息: Starting [org.eclipse.gemini.blueprint.extender] bundle v.[2.0.0.M02]
    osgi> 一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.support.ExtenderConfiguration start
    信息: No custom extender configuration detected; using defaults...
    一月 07, 2017 3:40:34 下午 org.springframework.scheduling.timer.TimerTaskExecutor afterPropertiesSet
    信息: Initializing Timer
    hello world!
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.support.DefaultOsgiApplicationContextCreator createApplicationContext
    信息: Discovered configurations {osgibundle:/META-INF/spring/*.xml} in bundle [Common (com.csdn.osgi.common)]
    Hello World!!
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.support.DefaultOsgiApplicationContextCreator createApplicationContext
    信息: Discovered configurations {config/*.xml} in bundle [Helloworld (com.csdn.osgi.helloworld)]
    一月 07, 2017 3:40:34 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
    信息: Refreshing OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.common, config=osgibundle:/META-INF/spring/*.xml): startup date [Sat Jan 07 15:40:34 CST 2017]; root of context hierarchy
    一月 07, 2017 3:40:34 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
    信息: Refreshing OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.helloworld, config=config/*.xml): startup date [Sat Jan 07 15:40:34 CST 2017]; root of context hierarchy
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext unpublishContextAsOsgiService
    信息: Application Context service already unpublished
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.blueprint.activator.support.BlueprintContainerCreator createApplicationContext
    信息: Discovered configurations {bundleentry://43.fwk2082351774/OSGI-INF/blueprint/beans.xml} in bundle [Helloworld (com.csdn.osgi.helloworld)]
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext unpublishContextAsOsgiService
    信息: Application Context service already unpublished
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.support.DefaultOsgiApplicationContextCreator createApplicationContext
    信息: Discovered configurations {osgibundle:/META-INF/spring/*.xml} in bundle [Database (com.csdn.osgi.database)]
    一月 07, 2017 3:40:34 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
    信息: Refreshing OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.database, config=osgibundle:/META-INF/spring/*.xml): startup date [Sat Jan 07 15:40:34 CST 2017]; root of context hierarchy
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext unpublishContextAsOsgiService
    信息: Application Context service already unpublished
    一月 07, 2017 3:40:34 下午 org.springframework.context.support.AbstractApplicationContext prepareRefresh
    信息: Refreshing OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.helloworld, config=bundleentry://43.fwk2082351774/OSGI-INF/blueprint/beans.xml): startup date [Sat Jan 07 15:40:34 CST 2017]; root of context hierarchy
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext unpublishContextAsOsgiService
    信息: Application Context service already unpublished
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from OSGi resource[bundleentry://43.fwk2082351774/OSGI-INF/blueprint/beans.xml|bnd.id=43|bnd.sym=com.csdn.osgi.helloworld]
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://37.fwk2082351774/META-INF/spring/beans.xml]
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://46.fwk2082351774/META-INF/spring/database.xml]
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://43.fwk2082351774/config/beans.xml]
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://43.fwk2082351774/config/company.xml]
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://46.fwk2082351774/META-INF/spring/dmconfig.xml]
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://37.fwk2082351774/META-INF/spring/dmconfig.xml]
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor stageOne
    信息: No outstanding OSGi service dependencies, completing initialization for OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.helloworld, config=bundleentry://43.fwk2082351774/OSGI-INF/blueprint/beans.xml)
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://43.fwk2082351774/config/dmconfig.xml]
    ================Hello World================
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
    信息: Loading XML bean definitions from URL [bundleentry://37.fwk2082351774/META-INF/spring/employee.xml]
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
    信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@215dd7af: defining beans [helloWorld,blueprintBundle,blueprintBundleContext,blueprintContainer,blueprintConverter]; root of factory hierarchy
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor stageOne
    信息: No outstanding OSGi service dependencies, completing initialization for OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.common, config=osgibundle:/META-INF/spring/*.xml)
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.blueprint.container.support.BlueprintContainerServicePublisher registerService
    信息: Publishing BlueprintContainer as OSGi service with properties {Bundle-SymbolicName=com.csdn.osgi.helloworld, Bundle-Version=1.0.0.qualifier, osgi.blueprint.container.version=1.0.0.qualifier, osgi.blueprint.container.symbolicname=com.csdn.osgi.helloworld}
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
    信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@68bf15f1: defining beans [object,length,buffer,current-time,list,employee,programmer]; root of factory hierarchy
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext publishContextAsOsgiServiceIfNecessary
    信息: Publishing application context as OSGi service with properties {org.eclipse.gemini.blueprint.context.service.name=com.csdn.osgi.helloworld, org.springframework.context.service.name=com.csdn.osgi.helloworld, Bundle-SymbolicName=com.csdn.osgi.helloworld, Bundle-Version=1.0.0.qualifier}
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyServiceManager doFindDependencies
    信息: Adding OSGi service dependency for importer [&employee] matching OSGi filter [(objectClass=com.csdn.osgi.domain.Employee)]
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.support.DefaultOsgiBundleApplicationContextListener onOsgiApplicationEvent
    信息: Application context successfully refreshed (OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.helloworld, config=bundleentry://43.fwk2082351774/OSGI-INF/blueprint/beans.xml))
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyServiceManager findServiceDependencies
    信息: OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.helloworld, config=config/*.xml) is waiting for unsatisfied dependencies [[&employee]]
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor stageOne
    信息: No outstanding OSGi service dependencies, completing initialization for OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.database, config=osgibundle:/META-INF/spring/*.xml)
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
    信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@30d1126b: defining beans [dataSource,sqlSessionFactory,sqlSessionTemplate,transactionManager,transactionTemplate,dbInfo,org.springframework.beans.factory.config.PropertyPlaceholderConfigurer#0,sqlMapService]; root of factory hierarchy
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.service.exporter.support.OsgiServiceFactoryBean registerService
    信息: Publishing service under classes [{com.csdn.osgi.domain.Employee}]
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.DependencyServiceManager$DependencyServiceListener serviceChanged
    信息: No unsatisfied OSGi service dependencies; completing initialization for OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.helloworld, config=config/*.xml)
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext publishContextAsOsgiServiceIfNecessary
    信息: Publishing application context as OSGi service with properties {org.eclipse.gemini.blueprint.context.service.name=com.csdn.osgi.common, org.springframework.context.service.name=com.csdn.osgi.common, Bundle-SymbolicName=com.csdn.osgi.common, Bundle-Version=1.0.0.qualifier}
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.support.DefaultOsgiBundleApplicationContextListener onOsgiApplicationEvent
    信息: Application context successfully refreshed (OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.common, config=osgibundle:/META-INF/spring/*.xml))
    SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
    SLF4J: Defaulting to no-operation (NOP) logger implementation
    SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
    一月 07, 2017 3:40:34 下午 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
    信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@4f805c92: defining beans [helloWorld1,helloWorld2,company,employee]; root of factory hierarchy
    ================Hello World================
    ================Hello World================
    =========Company=========
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext publishContextAsOsgiServiceIfNecessary
    信息: Publishing application context as OSGi service with properties {org.eclipse.gemini.blueprint.context.service.name=com.csdn.osgi.helloworld, org.springframework.context.service.name=com.csdn.osgi.helloworld, Bundle-SymbolicName=com.csdn.osgi.helloworld, Bundle-Version=1.0.0.qualifier}
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.support.DefaultOsgiBundleApplicationContextListener onOsgiApplicationEvent
    信息: Application context successfully refreshed (OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.helloworld, config=config/*.xml))
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.service.exporter.support.OsgiServiceFactoryBean registerService
    信息: Publishing service under classes [{org.apache.ibatis.session.SqlSession}]
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.context.support.AbstractOsgiBundleApplicationContext publishContextAsOsgiServiceIfNecessary
    信息: Publishing application context as OSGi service with properties {org.eclipse.gemini.blueprint.context.service.name=com.csdn.osgi.database, org.springframework.context.service.name=com.csdn.osgi.database, Bundle-SymbolicName=com.csdn.osgi.database, Bundle-Version=1.0.0.qualifier}
    一月 07, 2017 3:40:34 下午 org.eclipse.gemini.blueprint.extender.internal.support.DefaultOsgiBundleApplicationContextListener onOsgiApplicationEvent
    信息: Application context successfully refreshed (OsgiBundleXmlApplicationContext(bundle=com.csdn.osgi.database, config=osgibundle:/META-INF/spring/*.xml))

从日志文件中可以分析出，Mybatis相关的Bean已经实例化成功，本节内容先介绍这么多，下篇文件中我们在其他Bundle中通过Mybatis-Spring插件提供的模版类操作数据库。

注意：上篇文章提到使用Mybatis-Spring插件版本为1.2.0，与Spring 3.0整合存在一定的问题，本文中笔者將Mybatis-Spring插件版本改为1.2.3。

[SouthEast]: /images/20221024/e815b8b2e3ca4b5c8aae7e7a6dd14775.png
[SouthEast 1]: /images/20221024/a2f36488b6364274abd9e6cebb4a1083.png
[SouthEast 2]: /images/20221024/331e2f57dc6a4fa09657e69cbe864576.png