C3P0数据库连接池

c3p0config.xml(文件名不能改）----》src下

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
<default-config>
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/day16</property>
<property name="user">root</property>
<property name="password">123</property>
<property name="initialPoolSize">10</property>
<property name="maxIdleTime">30</property>
<property name="maxPoolSize">20</property>
<property name="minPoolSize">5</property>
<property name="maxStatements">200</property>
</default-config>

<named-config name="mysql">
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/day16</property>
<property name="user">root</property>
<property name="password">123</property>
<property name="acquireIncrement">50</property>
<property name="initialPoolSize">10</property>
<property name="minPoolSize">50</property>
<property name="maxPoolSize">100</property><!-- intergalactoApp adopts a different approach to configuring statement caching -->
<property name="maxStatements">0</property>
<property name="maxStatementsPerConnection">5</property>
</named-config>

<named-config name="oracle">
<property name="acquireIncrement">50</property>
<property name="initialPoolSize">100</property>
<property name="minPoolSize">50</property>
<property name="maxPoolSize">1000</property><!-- intergalactoApp adopts a different approach to configuring statement caching -->
<property name="maxStatements">0</property>
<property name="maxStatementsPerConnection">5</property>
</named-config>
</c3p0-config>

public class C3p0 {
    private static ComboPooledDataSource  ds=null;
    /*
　　不在配置文件配的时候
　　static{
        ds=new ComboPooledDataSource();
        try {
            ds.setDriverClass("com.mysql.jdbc.Driver");
            ds.setJdbcUrl("jdbc:mysql://localhost:3306/day16");
            ds.setUser("root");
            ds.setPassword("123");
            ds.setMaxPoolSize(30);
            ds.setMinPoolSize(3);
            ds.setInitialPoolSize(10);
            ds.setAcquireIncrement(1);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }*/
    
    static{
        ds=new ComboPooledDataSource("mysql");
        /*
         * 这里可以切换数据库，get----使用的是默认的连接池，而有参数的时候就用户名字
         * 对应下的配置的连接池
         */
    }
    
    public static Connection getConnection() throws SQLException{
        return ds.getConnection();
    }