Spring配置数据源

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1.1数据源(连接池)使用

数据源为提高程序性能出现

实例化数据源,初始化连接资源

使用资源时从数据源中获取

使用完毕将连接资源归还给数据源

常见数据源:DBCP C3P0 BoneCP Druid

1.1数据源开发步骤

1导入数据源的坐标和数据库驱动坐标

 <dependency>
           <groupId>mysql</groupId>
           <artifactId>mysql-connector-java</artifactId>
           <version>5.1.47</version>
       </dependency>
       <dependency>
           <groupId>c3p0</groupId>
           <artifactId>c3p0</artifactId>
           <version>0.9.1.2</version>
       </dependency>
       <dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>druid</artifactId>
           <version>1.1.10</version>
       </dependency>
       <dependency>
           <groupId>junit</groupId>
           <artifactId>junit</artifactId>
           <version>4.12</version>
           <scope>test</scope>
       </dependency>

2 创建数据源对象

   @Test
//测试手动创建 c3p0数据源
    public void dataSourceTest() throws Exception {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test");
        dataSource.setUser("root");
        dataSource.setPassword("root");
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }
    @Test
    public void druidTest() throws Exception{
        DruidDataSource druidDataSource = new DruidDataSource();
        druidDataSource.setDriverClassName("com.mysql.jdbc.Driver");
        druidDataSource.setUrl("jdbc:mysql://localhost:3306/test");
        druidDataSource.setUsername("root");
        druidDataSource.setPassword("root");
        DruidPooledConnection connection = druidDataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

2 设置数据源基本的连接数据

1.2 抽取jdbc.properties配置文件

1.在resources下新建jdbc.properties配置文件

2.配置

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.user=root
jdbc.password=root

3.读取properties配置文件

@Test  //测试c3p0数据源(使用properties配置文件)
    public void c3p0Test() throws Exception {
        ResourceBundle jdbc = ResourceBundle.getBundle("jdbc");
        String driver = jdbc.getString("jdbc.driver");
        String url = jdbc.getString("jdbc.url");
        String user = jdbc.getString("jdbc.user");
        String password = jdbc.getString("jdbc.password");
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(driver);
        dataSource.setJdbcUrl(url);
        dataSource.setUser(user);
        dataSource.setPassword(password);
        Connection connection = dataSource.getConnection();
        System.out.println(connection);
        connection.close();
    }

1.3 Spring配置数据源

可以将dataSource的创建权交给Spring容器

1.导入Spring 坐标

2.创建配置文件

      <bean id="druidDataSource" class="com.alibaba.druid.pool.DruidDataSource">
          <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
          <property name="url" value="jdbc:mysql://localhost:3306/test"></property>
          <property name="username" value="root"></property>
          <property name="password" value="root"></property>
      </bean>

3.从Spring容器中获取bean

    @Test
    public void testSpringContext() throws Exception {
        ApplicationContext app=new ClassPathXmlApplicationContext("applicationContext.xml");
        DruidDataSource druidDataSource = app.getBean(DruidDataSource.class);
        DruidPooledConnection connection = druidDataSource.getConnection();
        System.out.println(connection);
        connection.close();
​
    }

1.4 Spring加载properties配置文件

1.配置.xml

image-20210331224846684.png

<?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">
     <context:property-placeholder location="classpath:jdbc.properties"/>
    <bean id="druidDataSource" class="com.alibaba.druid.pool.DruidDataSource">
          <property name="driverClassName" value="${jdbc.driver}"></property>
          <property name="url" value="${jdbc.url}"></property>
          <property name="username" value="${jdbc.user}"></property>
          <property name="password" value="${jdbc.password}"></property>
      </bean>
</beans>