<?xml version="1.0" encoding="UTF-8"?>

<!-- Spring 配置文件的根元素，使用Spring-beans-4.0.xsd语义约束 -->

<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xmlns="http://www.springframework.org/schema/beans"

    xmlns:context="http://www.springframework.org/schema/context"

    xsi:schemaLocation="http://www.springframework.org/schema/beans

http://www.springframework.org/schema/beans/spring-beans-4.0.xsd

http://www.springframework.org/schema/context

http://www.springframework.org/schema/context/spring-context-4.0.xsd">

    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">

        <property name="locations">

            <list>

                <value>dbconn.properties</value>

                <!-- 如果有多个属性文件，依次在下面列出来 -->

                <!-- <value>wawa.properties</value> -->

            </list>

        </property>

    </bean>

    <!-- 对于采用基于XML Schema的配置文件而言，如果导入了context：命名空间，则可采用如下方式来配置该属性占位符 -->

    <!-- <context:property-placeholder location="classpath:wawa.properties"/> -->

    <!-- 定义数据源Bean，使用C3P0数据源实现 -->

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"

        destroy-method="close">

        <!-- Spring容器将从PropertyPlaceholderConfigurer指定的属性文件中搜索这些key对应的value，并为该Bean的属性值设置这些value值 -->

        <property name="driverClass" value="${jdbc.driverClassName}" />

        <property name="jdbcUrl" value="${jdbc.url}" />

        <property name="user" value="${jdbc.username}" />

        <property name="password" value="${jdbc.password}" />

    </bean>

</beans>

jdbc.driverClassName=com.mysql.jdbc.Driver

jdbc.url=jdbc:mysql://localhost:3306/spring

jdbc.username=root

jdbc.password=system

package edu.pri.lime._8_1_4.main;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.SQLException;

import javax.sql.DataSource;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {

    public static void main(String[] args) {

        ApplicationContext ctx = new ClassPathXmlApplicationContext("app_8_1_4.xml");

        DataSource ds = null;

        PreparedStatement pstmt = null;

        Connection conn = null;

        try {

            ds = ctx.getBean("dataSource",DataSource.class);

            conn = ds.getConnection();

            pstmt = conn.prepareStatement("insert into news_inf values(null,?,?)");

            pstmt.setString(1, "lime");

            pstmt.setString(2, "Oracle");

            pstmt.executeUpdate();

        } catch (SQLException e) {

            e.printStackTrace();

        }finally{

            if(pstmt != null)

                try {

                    pstmt.close();

                } catch (SQLException e1) {

                    // TODO Auto-generated catch block

                    e1.printStackTrace();

                }

            if(conn != null)

                try {

                    conn.close();

                } catch (SQLException e) {

                    // TODO Auto-generated catch block

                    e.printStackTrace();

                }

        }

    }

}