九IOC操作Bean管理（外部属性文件）

Posted 2021-05-20 上善若水

1. 直接配置数据库信息

   • 配置德鲁伊连接池

   • 引入德鲁伊连接池依赖jar包
     

   <?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">   
      <!--直接配置连接池-->   
      <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">   
         <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>   
         <property name="url" value="jdbc:mysql://localhost:3306/userDb"></property>   
         <property name="username" value="root"></property>   
         <property name="password" value="root"></property>   
      </bean>   
   </beans> 
   

2. 引入外部属性文件配置数据库连接池

   • 创建外部属性文件，properties格式文件，写数据库信息

     prop.driverClass=com.mysql.jdbc.Driver
     prop.url=jdbc:mysql://localhost:3306/userDb
     prop.userName=rootprop.password=root
     

   • 把外部properties属性文件引入到spring配置文件中

     引入context名称空间

     <?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: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/context http://www.springframework.org/schema/context/spring-context.xsd">   
     </beans>  
     

3. 在 spring 配置文件使用标签引入外部属性文件

   <?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:util="http://www.springframework.org/schema/util"   
          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/util http://www.springframework.org/schema/util/spring-util.xsd   
                              http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">   
      
       <!--直接配置连接池-->   
       <!--<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">   
           <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>   
           <property name="url" value="jdbc:mysql://localhost:3306/userDb"></property>   
           <property name="username" value="root"></property>   
           <property name="password" value="root"></property>   
       </bean>-->   
      
       <!--引入外部属性文件-->   
       <context:property-placeholder location="classpath:jdbc.properties"/>   
      
       <!--配置连接池-->   
       <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">   
           <property name="driverClassName" value="${prop.driverClass}"></property>   
           <property name="url" value="${prop.url}"></property>   
           <property name="username" value="${prop.userName}"></property>   
           <property name="password" value="${prop.password}"></property>   
       </bean>   
      
   </beans>