c3p0写连接池 Demo

 1 <c3p0-config>
 2     <!--  默认配置，有且仅可出现一次 ，如果没有指定则使用这个配置 -->
 3     <default-config>
 4         <!-- 连接超时时间 30秒 -->
 5         <property name="checkoutTimeout">30000</property>
 6         <!-- 每30秒检查一次空闲时间 -->
 7         <property name="idleConnectionTestPeriod">30</property>
 8         <!-- 初始化池大小 -->
 9         <property name="initialPoolSize">10</property>
10         <!-- 最多的connection的空闲时间 -->
11         <property name="maxIdleTime">30</property>
12         <!-- 池中最大连接数 -->
13         <property name="maxPoolSize">100</property>
14         <!-- 池中最小连接数 -->
15         <property name="minPoolSize">10</property>
16         <!-- 批处理的语句 -->
17         <property name="maxStatements">50</property>
18         <!-- 每次增长几个连接 -->
19         <property name="acquireIncrement">3</property>        
20         
21         <property name="driverClass">com.mysql.jdbc.Driver</property>
22         <property name="jdbcUrl">
23             <![CDATA[jdbc:mysql:///jdbcdb?useUnicode=true&characterEncoding=UTF-8]]>
24         </property>
25         <property name="user">root</property>
26         <property name="password">mysql</property>    
27         
28     </default-config> 
29     <!-- 命名的配置 -->
30     <named-config name="MyDb">
31         <property name="driverClass">com.mysql.jdbc.Driver</property>
32         <property name="jdbcUrl">
33             <![CDATA[jdbc:mysql://localhost/bookstore]]>
34         </property>
35         <property name="user">root</property>
36         <property name="password">mysql</property>
37         <property name="acquireIncrement">5</property><!-- 如果池中数据连接不够时一次增长多少个 -->
38         <property name="initialPoolSize">100</property>
39         <property name="minPoolSize">50</property>
40         <property name="maxPoolSize">1000</property>
41         <property name="maxStatements">0</property>
42         <property name="maxStatementsPerConnection">5</property> <!-- he‘s important, but there‘s only one of him -->
43     </named-config>
44 </c3p0-config> 
45 
46 c3p0-config.xml

 1 private static DataSource ds;
 2     private DataSourceUtils(){}
 3     static{
 4         ds=new  ComboPooledDataSource();//默认读取c3p0中默认配置
 5         //new ComboPooledDataSource("MyDb");//读取c3p0配置在的named-config中的配置
 6     }
 7     
 8     public static DataSource getDataSource()
 9     {
10         return ds;
11     }