com.mchange.v2.c3p0.ComboPooledDataSource：數據庫連接池的一種
C3P0是一個開放源代碼的JDBC連接池，它在lib目錄中與Hibernate一起發布,包括了實現jdbc3和jdbc2擴展規范說明的Connection 和Statement 池的DataSources 對象。
1.需要的jar包：c3p0-0.9.1.2.jar
1 <dependency> 2 <groupId>c3p0</groupId> 3 <artifactId>c3p0</artifactId> 4 <version>0.9.1.2</version> 5 </dependency>
2.ComboPooledDataSource連接數據庫方式：
（1）代碼連接：
1 public class TestCombo{ 2 private ComboPooledDataSource dataSource; private TestCombo() { 3 try { 4 dataSource = new ComboPooledDataSource(); 5 dataSource.setUser(root); 6 dataSource.setPassword(123456); 7 dataSource.setJdbcUrl(jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8"); 8 dataSource.setDriverClass(com.mysql.jdbc.Driver); 9 dataSource.setInitialPoolSize(); 10 dataSource.setAcquireIncrement(); 11 dataSource.setMinPoolSize(); 12 dataSource.setMaxPoolSize(); 13 dataSource.setMaxStatements(); 14 dataSource.setMaxIdleTime(); 15 dataSource.setIdleConnectionTestPeriod(); 16 dataSource.setAcquireRetryAttempts(); 17 18 } catch (Exception e) { 19 throw new RuntimeException(e); 20 } 21 } 22 23 24 public Connection getConnection() { 25 try { 26 return dataSource.getConnection(); 27 } catch (Exception e) { 28 throw new RuntimeException("can not get sms database connection ", e); 29 } 30 } 31 32 } 33 --------------------- 34 作者：chenpuzhen 35 來源：CSDN 36 原文：https://blog.csdn.net/chenpuzhen/article/details/80610044 37 版權聲明：本文為博主原創文章，轉載請附上博文鏈接！
（2）配置文件連接：
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!--destroy-method="close"的作用是當數據庫連接不使用的時候,就把該連接重新放到數據池中,方便下次使用調用. --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close" > <property name="driverClass" value="${database.driver}" /> <property name="jdbcUrl" value="${database.url}" /> <property name="user" value="${database.username}" /> <property name="password" value="${database.password}" /> <property name="loginTimeout" value="3000"></property> <!--checkoutTimeout從池中拿未使用的連接，超時設置，如果沒有設置，就不超時. --> <property name="checkoutTimeout" value="30000"></property> <property name="preferredTestQuery" value="select 1 from dual"></property> <!--每18000秒檢查所有連接池中的空閑連接。Default: 0 --> <property name="idleConnectionTestPeriod" value="18000"></property> <!--testConnectionOnCheckout:如果設置為true,每次從池中取一個連接，將做一下測試，使用automaticTestTable 或者 preferredTestQuery,做一條查詢語句.看看連接好不好用，不好用，就關閉它，重新從池中拿一個. --> <property name="testConnectionOnCheckout" value="true"></property> <!--連接池中保留的最小連接數。--> <property name="minPoolSize" value="5"></property> <!--連接池中保留的最大連接數。-->
<property name="maxPoolSize" value="100"></property> <!-- 初始化池大小 --> <property name="initialPoolSize" value="10"></property> <!--當連接池中的連接耗盡的時候c3p0一次同時獲取的連接數。 --> <property name="acquireIncrement" value="5"></property> <!--從數據庫獲取新連接失敗后重復嘗試的次數。Default: 30 --> <property name="acquireRetryAttempts" value="30"></property> <property name="acquireRetryDelay" value="1000"></property> <!--最大空閑時間,3600秒內未使用則連接被丟棄。若為0則永不丟棄。--> <property name="maxIdleTime" value="3600"></property> </bean> <!--另一數據庫連接 --> <bean id="dataSourceQuas" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close" > <property name="driverClass" value="${quas.database.driver}" /> <property name="jdbcUrl" value="${quas.database.url}" /> <property name="user" value="${quas.database.username}" /> <property name="password" value="${quas.database.password}" /> <property name="loginTimeout" value="3000"></property> <property name="checkoutTimeout" value="30000"></property> <property name="preferredTestQuery" value="select 1 from dual"></property> <property name="idleConnectionTestPeriod" value="18000"></property> <property name="testConnectionOnCheckout" value="true"></property> <property name="minPoolSize" value="5"></property> <property name="maxPoolSize" value="100"></property> <property name="initialPoolSize" value="10"></property> <property name="acquireIncrement" value="5"></property> <property name="acquireRetryAttempts" value="30"></property> <property name="acquireRetryDelay" value="1000"></property> <property name="maxIdleTime" value="3600"></property> </bean> <bean id="dataSourceCtps" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close" > <property name="driverClass" value="${ctps.database.driver}" /> <property name="jdbcUrl" value="${ctps.database.url}" /> <property name="user" value="${ctps.database.username}" /> <property name="password" value="${ctps.database.password}" /> <property name="loginTimeout" value="3000"></property> <property name="checkoutTimeout" value="30000"></property> <property name="preferredTestQuery" value="select 1 from dual"></property> <property name="idleConnectionTestPeriod" value="18000"></property> <property name="testConnectionOnCheckout" value="true"></property> <property name="minPoolSize" value="5"></property> <property name="maxPoolSize" value="100"></property> <property name="initialPoolSize" value="10"></property> <property name="acquireIncrement" value="5"></property> <property name="acquireRetryAttempts" value="30"></property> <property name="acquireRetryDelay" value="1000"></property> <property name="maxIdleTime" value="3600"></property> </bean> </beans>
（3）資源文件設置數據庫相關值：database.properties
