Spring数据库连接池

创建JDBC.properties,里面写连接数据库需要的4个值

jdbc.user=root
jdbc.password=123456
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/lhw

applicationContext中的配置

<bean id="comboPooledDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
     <property name="user" value="${jdbc.user}"></property>
     <property name="password" value="${jdbc.password}"></property>
     <property name="driverClass" value="${jdbc.driver}"></property>
       <property name="jdbcUrl" value="${jdbc.url}"></property>
  </bean>

简单的查询数据

public void test() throws SQLException {
        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
        DataSource dataSource = ac.getBean(DataSource.class);
        Connection con = dataSource.getConnection();
        String sql="select * from student";
        PreparedStatement ps = con.prepareStatement(sql);
        ResultSet rs = ps.executeQuery();
        while(rs.next()){
            String name = rs.getString("name");
            String school = rs.getString("school");
            double score = rs.getDouble("score");
            System.out.println(name+school+score);
        }
    }