使用placeholder实现动态配置persistence.xml
项目用到spring data jpa 和 hibernate, 正常情况下会在src/resources下创建META-INF目录, 并在其中创建persistence.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <persistence version="2.0" 3 xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://java.sun.com/xml/ns/persistence 5 http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> 6 7 <persistence-unit name="myJPA" transaction-type="RESOURCE_LOCAL"> 8 <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider> 9 <properties> 10 <!--配置Hibernate方言 --> 11 <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect" /> 12 <!--配置数据库驱动 --> 13 <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver" /> 14 <!--配置数据库用户名 --> 15 <property name="hibernate.connection.username" value="root" /> 16 <!--配置数据库密码 --> 17 <property name="hibernate.connection.password" value="root" /> 18 <!--配置数据库url --> 19 <property name="hibernate.connection.url" 20 value="jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8" /> 21 <!--设置外连接抓取树的最大深度 --> 22 <property name="hibernate.max_fetch_depth" value="3" /> 23 <property name="hibernate.jdbc.fetch_size" value="18" /> 24 <property name="hibernate.jdbc.batch_size" value="10" /> 25 <!--自动输出schema创建DDL语句 --> 26 <property name="hibernate.hbm2ddl.auto" value="update" /> 27 <property name="hibernate.show_sql" value="true" /> 28 <property name="hibernate.format_sql" value="true" /> 29 <property name="javax.persistence.validation.mode" value="none" /> 30 </properties> 31 </persistence-unit> 32 </persistence>
applicationContext.xml中
<!-- 定义实体管理器工厂 --> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="persistenceUnitName" value="myJPA" /> </bean>
但是现在需要在applicationContext.xml中配置 dataSource, 而其中用到了 数据库地址,用户名这些信息, 为了方便, 统一使用 properties 文件保存信息, 并做如下修改
persistence.xml
<?xml version="1.0" encoding="UTF-8"?> <persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"> <persistence-unit name="myJPA" transaction-type="RESOURCE_LOCAL"/> </persistence>
在 src/resources 下创建 config.properties 文件, 并输入配置项
database.driver=com.mysql.jdbc.Driver database.url=jdbc:mysql://localhost:3306/lottery?autoReconnect=true&useUnicode=true&characterEncoding=UTF-8 database.username=root database.password=root
applicationContext.xml
1 <context:property-placeholder location="classpath:config.properties" system-properties-mode="OVERRIDE"/> 2 3 <!-- 使用spring 加载jdbc驱动 --> 4 <bean id="dataSourceTemplate" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 5 <property name="driverClassName" value="${database.driver}" /> 6 <property name="url" value="${database.url}" /> 7 <property name="username" value="${database.username}" /> 8 <property name="password" value="${database.password}" /> 9 </bean> 10 11 <!--tomcat jdbc pool数据源配置--> 12 <bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource" destroy-method="close"> 13 <!-- 通过引用加载数据库信息 --> 14 <property name="dataSource" ref="dataSourceTemplate"/> 15 16 <property name="jmxEnabled" value="true"/> 17 <property name="testWhileIdle" value="true"/> 18 <property name="testOnBorrow" value="true"/> 19 <property name="testOnReturn" value="false"/> 20 <property name="validationInterval" value="30000"/> 21 <property name="validationQuery" value="SELECT 1"/> 22 <property name="timeBetweenEvictionRunsMillis" value="30000"/> 23 <property name="initialSize" value="10"/> 24 <property name="maxActive" value="40"/> 25 <property name="minIdle" value="10"/> 26 <property name="maxIdle" value="20"/> 27 <property name="maxWait" value="10000"/> 28 <property name="minEvictableIdleTimeMillis" value="30000"/> 29 <property name="logAbandoned" value="false"/> 30 <property name="removeAbandoned" value="true"/> 31 <property name="removeAbandonedTimeout" value="60"/> 32 <property name="jdbcInterceptors" value="org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer"/> 33 </bean> 34 35 36 <!-- 定义实体管理器工厂 --> 37 <bean id="entityManagerFactory" 38 class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> 39 <property name="persistenceUnitName" value="myJPA" /> 40 <property name="dataSource" ref="dataSource" /> 41 <property name="jpaVendorAdapter"> 42 <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> 43 <property name="showSql" value="true"/> 44 <property name="databasePlatform" value="org.hibernate.dialect.MySQL5Dialect"/> 45 <property name="generateDdl" value="true" /> 46 <property name="database" value="MYSQL" /> 47 </bean> 48 </property> 49 <property name="persistenceProviderClass" value="org.hibernate.jpa.HibernatePersistenceProvider"/> 50 <property name="jpaProperties"> 51 <props> 52 <prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop> 53 <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop> 54 <prop key="hibernate.connection.driver_class">com.mysql.jdbc.Driver</prop> 55 <prop key="hibernate.connection.url">${database.url}</prop> 56 <prop key="hibernate.connection.username">${database.username}</prop> 57 <prop key="hibernate.connection.password">${database.password}</prop> 58 <prop key="hibernate.max_fetch_depth">3</prop> 59 <prop key="hibernate.jdbc.fetch_size">18</prop> 60 <prop key="hibernate.jdbc.batch_size">10</prop> 61 <prop key="hibernate.hbm2ddl.auto">update</prop> 62 <prop key="hibernate.show_sql">true</prop> 63 <prop key="hibernate.format_sql">true</prop> 64 <prop key="javax.persistence.validation.mode">none</prop> 65 </props> 66 </property> 67 </bean>
dataSourceTemplate 和 dataSource 这么定义是为解决 Tomcat jdbc pool 加载时找不到 Driver 类的错误. http://www.cnblogs.com/ykt8465279130/p/3669355.html
