spring学习笔记九

数据源对象管理

1、加入pom坐标

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.16</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/c3p0/c3p0 -->
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.16</version>
        </dependency>

2、jdbc.properties配置文件

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/spring_db
jdbc.username=root
jdbc.password=mima12341

3、spring配置文件

3.1、开启context命名空间

<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"  这里是新增
       xsi:schemaLocation="
       http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context  这里是新增
       http://www.springframework.org/schema/context/spring-context.xsd  这里是新增
">

3.2、完整配置文件 

<?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: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
">
    <!--step1:    开启命名空间-->
    <!--step2:    使用context空间加载properties文件-->
    <context:property-placeholder location="jdbc.properties"/>
    <bean id="datasource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driver}" />
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
    </bean>

</beans>

4、使用方法

public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
        DataSource dataSource = (DataSource)ctx.getBean("datasource");
        System.out.println(dataSource);
    }

5、总结

• 3.1开启context命名空间
• 配置context:property-placeholder 设置location为配置文件名
• 配置datasource的Bean
• 使用${xxxx}获取配置文件中设置的值