C3P0连接池配置

 1 /**
 2  * 使用本类的方法，必须提供c3p0-copnfig.xml文件
 3  * 
 4  * @author C
 5  */
 6 public class JdbcUtils {
 7     // 饿汉式
 8     private static DataSource ds = new ComboPooledDataSource();
 9     /**
10      * 它为null表示没有事务 
11      * 它不为null表示有事务 
12      * 当开启事务时，需要给它赋值 
13      * 当结束事务时，需要给它赋值为null
14      * 并且在开启事务时，让dao的多个方法共享这个Connection
15      */
16     private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();
17 
18     public static DataSource getDataSource() {
19         return ds;
20     }
21     /**
22      * dao使用本方法来获取连接
23      * 
24      * @return
25      * @throws SQLException
26      */
27     public static Connection getConnection() throws SQLException {
28         /*
29          * 如果有事务，返回当前事务的con 如果没有事务，通过连接池返回新的con
30          */
31         Connection con = tl.get();// 获取当前线程的事务连接
32         if (con != null) {
33             return con;
34         }
35         return ds.getConnection();
36     }
37 
38     /**
39      * 开启事务
40      * @throws SQLException 
41      */
42     public static void beginTransaction() throws SQLException {
43         Connection con = tl.get();//获取当前线程的事务连接
44         if (con != null) {
45             throw new SQLException("已经开启了事务，不能重复开启！");
46         } 
47         con = ds.getConnection();//给con赋值，表示开启了事务
48         con.setAutoCommit(false);//设置为手动提交
49         tl.set(con);////把当前事务连接放到tl中
50     }
51     
52     /**
53      * 提交事务
54      * @throws SQLException 
55      */
56     public static void commitTransaction() throws SQLException {
57         Connection con = tl.get();//获取当前线程的事务连接
58         if(con == null) throw new SQLException("没有事务不能提交！");
59         con.commit();//提交事务
60         con.close();//关闭连接
61         con = null;//表示事务结束！
62         tl.remove();
63     }
64     
65     /**
66      * 释放Connection
67      * @param con
68      * @throws SQLException 
69      */
70     public static void releaseConnection(Connection connection) throws SQLException {
71         Connection con = tl.get();//获取当前线程的事务连接
72         if(connection != con) {//如果参数连接，与当前事务连接不同，说明这个连接不是当前事务，可以关闭！
73             if(connection != null &&!connection.isClosed()) {//如果参数连接没有关闭，关闭之！
74                 connection.close();
75             }
76         }
77     }
78 }

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <c3p0-config>
 3     <default-config> 
 4         <property name="jdbcUrl">
 5                 jdbc:mysql://localhost:3306/cms
 6         </property>
 7         <property name="driverClass">com.mysql.jdbc.Driver</property>
 8         <property name="user">root</property>
 9         <property name="password">root</property>
10         
11         <property name="acquireIncrement">3</property>
12         <property name="initialPoolSize">10</property>
13         <property name="minPoolSize">2</property>
14         <property name="maxPoolSize">10</property>
15     </default-config>
16 </c3p0-config>

1 public class JdbcUtilTest {
2     
3     @Test
4     public void jdbcUtils() throws SQLException {
5         Connection con = JdbcUtils.getConnection();
6         System.out.println(con);
7     }
8 }

1 2014-8-13 9:17:30 com.mchange.v2.log.MLog <clinit>
2 信息: MLog clients using java 1.4+ standard logging.
3 2014-8-13 9:17:30 com.mchange.v2.c3p0.C3P0Registry banner
4 信息: Initializing c3p0-0.9.2-pre1 [built 27-May-2010 01:00:49 -0400; debug? true; trace: 10]
5 2014-8-13 9:17:30 com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource getPoolManager
6 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 -> 1bqv9u3931kv3noythxveh|1786e64, debugUnreturnedConnectionStackTraces -> false, description -> null, driverClass -> com.mysql.jdbc.Driver, factoryClassLocation -> null, forceIgnoreUnresolvedTransactions -> false, identityToken -> 1bqv9u3931kv3noythxveh|1786e64, idleConnectionTestPeriod -> 0, initialPoolSize -> 10, jdbcUrl -> jdbc:mysql://localhost:3306/cms, maxAdministrativeTaskTime -> 0, maxConnectionAge -> 0, maxIdleTime -> 0, maxIdleTimeExcessConnections -> 0, maxPoolSize -> 10, maxStatements -> 0, maxStatementsPerConnection -> 0, minPoolSize -> 2, numHelperThreads -> 3, numThreadsAwaitingCheckoutDefaultUser -> 0, preferredTestQuery -> null, properties -> {user=******, password=******}, propertyCycle -> 0, statementCacheNumDeferredCloseThreads -> 0, statementDestroyerNumActiveThreads -> -1, statementDestroyerNumConnectionsInUseAllUsers -> -1, statementDestroyerNumConnectionsInUseDefaultUser -> -1, statementDestroyerNumConnectionsWithDeferredDestroyStatementsAllUsers -> -1, statementDestroyerNumConnectionsWithDeferredDestroyStatementsDefaultUser -> -1, statementDestroyerNumDeferredDestroyStatementsAllUsers -> -1, statementDestroyerNumDeferredDestroyStatementsDefaultUser -> -1, statementDestroyerNumIdleThreads -> -1, statementDestroyerNumTasksPending -> -1, statementDestroyerNumThreads -> -1, testConnectionOnCheckin -> false, testConnectionOnCheckout -> false, unreturnedConnectionTimeout -> 0, usesTraditionalReflectiveProxies -> false ]
7 <span style="color:#ff0000;">com.mchange.v2.c3p0.impl.NewProxyConnection@1e87719</span>

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2     log4j.appender.c1=org.apache.log4j.ConsoleAppender
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4     log4j.appender.c1.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} [%p] %m [%t] %c [%l]%n
5     #log4j.appender.f1.File=/WEB-INF/logs/file.log
6     #log4j.appender.f1=org.apache.log4j.DailyRollingFileAppender
7     #log4j.appender.f1.layout=org.apache.log4j.PatternLayout
8     #log4j.appender.f1.layout.ConversionPattern=%d{yyyy-MM-dd HH\:mm\:ss} [%p] %m [%t] %c [%l]%n

com.mchange.v2.c3p0.impl.NewProxyConnection@c62c8