pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.gq</groupId>
    <artifactId>spring-ioc-v2</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <!-- 整合c3p0连接池 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.40</version>
        </dependency>
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5.1</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

/spring-ioc-v2/src/main/resources/config.properties

jdbcDriver=com.mysql.jdbc.Driver
jdbcUrl=jdbc:mysql:///test
jdbcUsername=root
jdbcPassword=123456

/spring-ioc-v2/src/main/resources/spring-configs.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans
    xmlns="http://www.springframework.org/schema/beans" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:util="http://www.springframework.org/schema/util"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
    xsi:schemaLocation="  
       http://www.springframework.org/schema/beans   
       http://www.springframework.org/schema/beans/spring-beans-4.3.xsd  
       http://www.springframework.org/schema/mvc   
       http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd   
       http://www.springframework.org/schema/tx   
       http://www.springframework.org/schema/tx/spring-tx-4.3.xsd   
       http://www.springframework.org/schema/aop 
       http://www.springframework.org/schema/aop/spring-aop-4.3.xsd
       http://www.springframework.org/schema/util 
       http://www.springframework.org/schema/util/spring-util-4.3.xsd
       http://www.springframework.org/schema/data/jpa 
       http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-4.3.xsd">
    <!--如何理解spring中的Bean对象:由spring框架管理的所有对象都是bean对象 -->
    <!-- Bean对象何时创建？要看对象是否配置延迟加载 -->
    <!-- Bean对象的默认作用域singleton(默认在内存中只有一份) -->
    <!-- 单例对象是何时销毁的？容器关闭时销毁 -->
    <!-- 系统底层会读取配置文件，并将配置信息封装到Properties对象(本质上是一个map)-->
    <util:properties id="cfg" location="classpath:config.properties"></util:properties>
    <!-- 整合c3p0连接池 name的第一个字母可以大写也可以小写 -->
    <bean id="c3p0" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <!--属性名如何查找，看源码类中的set方法  -->
        <property name="driverClass" value="#{cfg.jdbcDriver}"></property>
        <property name="jdbcUrl" value="#{cfg.jdbcUrl}"></property>
        <property name="user" value="#{cfg.jdbcUsername}"></property>
        <property name="password" value="#{cfg.jdbcPassword}"></property>
    </bean>
</beans>

package test;

import org.junit.After;
import org.junit.Before;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestBase {
    protected ClassPathXmlApplicationContext ctx;
    @Before
    public void init(){
        ctx=new ClassPathXmlApplicationContext("spring-configs.xml");
    }
    @After
    public void close(){
        ctx.close();
    }
}

package test;

import java.sql.Connection;
import java.sql.SQLException;

import org.junit.Assert;
import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class TestDataSource02 extends TestBase{
    @Test
    public void testC3PDataSource() throws SQLException{
        //获取bean对象
        ComboPooledDataSource ds = ctx.getBean("c3p0",ComboPooledDataSource.class);
        //用接口接收对象，测试对象值是否为空
        Assert.assertNotEquals(null, ds);
        //通过bean对象获取与数据库的连接
        Connection conn = ds.getConnection();
        System.out.println(conn);
    }
}

运行结果

九月 04, 2018 2:48:25 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@6ed3ef1: startup date [Tue Sep 04 14:48:25 CST 2018]; root of context hierarchy
九月 04, 2018 2:48:25 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring-configs.xml]
OpenDataSource.OpenDataSource()-2
OpenDataSource.init()
九月 04, 2018 2:48:26 下午 com.mchange.v2.log.MLog <clinit>
信息: MLog clients using java 1.4+ standard logging.
九月 04, 2018 2:48:26 下午 com.mchange.v2.c3p0.C3P0Registry banner
信息: Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]
九月 04, 2018 2:48:26 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
信息: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 3, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> 1hge19c9x19bjvx5ae8xt|46238e3f, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1hge19c9x19bjvx5ae8xt|46238e3f, idleConnectionTestPeriod -> 0, initialPoolSize -> 3, jdbcUrl -> jdbc:mysql:///test, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 15, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 3, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
com.mchange.v2.c3p0.impl.NewProxyConnection@38c5cc4c
九月 04, 2018 2:48:26 下午 org.springframework.context.support.ClassPathXmlApplicationContext doClose
信息: Closing org.springframework.context.support.ClassPathXmlApplicationContext@6ed3ef1: startup date [Tue Sep 04 14:48:25 CST 2018]; root of context hierarchy
OpenDataSource.destory()