配置数据库连接池C3P0两种方式
1.手动配置
//方式一
@Test
public void testGetConnection() throws Exception{
//获取C3P0数据库连接池
ComboPooledDataSource cpds = new ComboPooledDataSource();
cpds.setDriverClass("com.mysql.jdbc.Driver");
cpds.setJdbcUrl("jdbc:mysql://localhost:3306/firstDB?rewriteBatchedStatements=true&useSSL=false&useUnicode=true&characterEncoding=UTF-8");
cpds.setUser("root");
cpds.setPassword("123");
//通过设置相关的参数，对数据库连接池进行管理:
//设置初始时数据库连接池中连接数
cpds.setInitialPoolSize(10);
Connection conn = cpds.getConnection();
System.out.println(conn);
//销毁c3p0数据库连接池
// DataSources.destroy(cpds);
}
//输出
十二月 22, 2019 9:07:23 下午 com.mchange.v2.log.MLog <clinit>
信息: MLog clients using java 1.4+ standard logging.
十二月 22, 2019 9:07:23 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]
十二月 22, 2019 9:07:23 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
信息: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 5, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> helloc3p0, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1eslg1oa7coogetzjd128|e6ea0c6, idleConnectionTestPeriod -> 0, initialPoolSize -> 10, jdbcUrl -> jdbc:mysql:///firstDB?rewriteBatchedStatements=true&useSSL=false&useUnicode=true&characterEncoding=UTF-8, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 100, maxStatements -> 50, maxStatementsPerConnection -> 2, minPoolSize -> 10, 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@3cda1055
2.通过XML文件配置
<?xml version="1.0" encoding="UTF-8" ?>
<c3p0-config>
<named-config name="helloc3p0">
<!-- 提供获取连接的4个基本信息 -->
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql:///firstDB?rewriteBatchedStatements=true&useSSL=false&useUnicode=true&characterEncoding=UTF-8</property>
<property name="user">root</property>
<property name="password">123</property>
<!-- 进行数据库连接池管理的基本信息 -->
<!-- 当数据库连接池中的连接数不够时，c3p0一次性向数据库服务器申请的链接数 -->
<property name="acquireIncrement">5</property>
<!-- c3p0数据库连接池中初始化时的连接数 -->
<property name="initialPoolSize">10</property>
<!-- c3p0数据库连接池中维护的最少连接数 -->
<property name="minPoolSize">10</property>
<!-- c3p0数据库连接池中维护的最多连接数 -->
<property name="maxPoolSize">100</property>
<!-- c3p0数据库连接池最多维护的Statement的个数 -->
<property name="maxStatements">50</property>
<!-- 每个连接中最多可以使用的Statement的个数 -->
<property name="maxStatementsPerConnection">2</property>
</named-config>
</c3p0-config>
//方式二:使用配置文件
@Test
public void testGetConnection1() throws Exception{
ComboPooledDataSource cpds = new ComboPooledDataSource("helloc3p0");
Connection conn = cpds.getConnection();
System.out.println(conn);
}
//输出
十二月 22, 2019 9:14:51 下午 com.mchange.v2.log.MLog <clinit>
信息: MLog clients using java 1.4+ standard logging.
十二月 22, 2019 9:14:51 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]
十二月 22, 2019 9:14:51 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
信息: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 5, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> helloc3p0, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1eslg1oa7coy242ipevg|e6ea0c6, idleConnectionTestPeriod -> 0, initialPoolSize -> 10, jdbcUrl -> jdbc:mysql:///firstDB?rewriteBatchedStatements=true&useSSL=false&useUnicode=true&characterEncoding=UTF-8, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 100, maxStatements -> 50, maxStatementsPerConnection -> 2, minPoolSize -> 10, 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@3cda1055
使用C3P0数据库连接池技术
public class JDBCUtils {
/**
* @Description: 使用C3P0的数据库连接池技术
* @Param:
* @return:
* @Author: fish
* @Date: 9:20 PM 2019/12/22
*/
//数据库连接池只需提供一个即可。
private static ComboPooledDataSource cpds = new ComboPooledDataSource("helloc3p0");
public static Connection getConnection1() throws Exception{
Connection conn = cpds.getConnection();
return conn;
}
}
@Test
public void getCustomerById(){
Connection conn = null;
try{
conn = JDBCUtils.getConnection1();
Customer customer = dao.getCustomerById(conn,8);
System.out.println(customer);
System.out.println("查询成功");
}catch (Exception e){
e.printStackTrace();
}finally {
JDBCUtils.closeResource(conn,null);
}
}
//输出
十二月 22, 2019 9:26:21 下午 com.mchange.v2.log.MLog <clinit>
信息: MLog clients using java 1.4+ standard logging.
十二月 22, 2019 9:26:21 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]
十二月 22, 2019 9:26:21 下午 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
信息: Initializing c3p0 pool... com.mchange.v2.c3p0.ComboPooledDataSource [ acquireIncrement -> 5, acquireRetryAttempts -> 30, acquireRetryDelay -> 1000, autoCommitOnClose -> false, automaticTestTable -> null, breakAfterAcquireFailure -> false, checkoutTimeout -> 0, connectionCustomizerClassName -> null, connectionTesterClassName -> com.mchange.v2.c3p0.impl.DefaultConnectionTester, dataSourceName -> helloc3p0, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1eslg1oa7cpcuno1i0imi9|e6ea0c6, idleConnectionTestPeriod -> 0, initialPoolSize -> 10, jdbcUrl -> jdbc:mysql:///firstDB?rewriteBatchedStatements=true&useSSL=false&useUnicode=true&characterEncoding=UTF-8, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 100, maxStatements -> 50, maxStatementsPerConnection -> 2, minPoolSize -> 10, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
Customer{id=8, name='陈道明', email='bdf@126.com', birth=1963-09-16 00:00:00.0}
查询成功
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