多个C3P0的java举例

在使用mysql时，如果数据库会被频繁多人调用，有必要使用连接池来帮助协调，使用C3P0连接池时想要用多个数据库时，需要分别定义ComboPooledDataSource的静态对象。举例如下：

public class ConnOfC3P0Util {
    private static Log logger = LogFactory.getLog(ConnOfC3P0Util.class);
    private static ComboPooledDataSource ds = new ComboPooledDataSource();
    private static ComboPooledDataSource ds2 = new ComboPooledDataSource("myApp"); 
    public static ComboPooledDataSource getDs() {
        return ds;
    }

    public static Connection getConnection() {
        try {
            logger.info("ds.getDataSourceName():"+ds.getDataSourceName());
            return ds.getConnection();

        } catch (SQLException e) {
            logger.error(e.getMessage(), e);
        }
        return null;
    }
    public static Connection getMyConnection() {
        try {
            logger.info("ds2.getDataSourceName():"+ds2.getDataSourceName());
            return ds2.getConnection();

        } catch (SQLException e) {
            logger.error(e.getMessage(), e);
        }
        return null;
    }

    public static void free(ResultSet rs, Statement st, Connection conn) {
        try {
            if (rs != null) {
                rs.close();
            }
        } catch (Exception e) {
            logger.error( e.getMessage(), e);
        } finally {
            try {
                if (st != null) {
                    st.close();
                }
            } catch (Exception e) {
                logger.error( e.getMessage(), e);
            } finally {
                if (conn != null) {
                    try {
                        conn.close();
                    } catch (SQLException e) {
                        logger.error(e.getMessage(), e);
                    }
                }
            }
        }
    }
}

相应的c3p0xml配置为：

<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
    <default-config>
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="user">XXX</property>
        <property name="password">XXX</property>
        <property name="jdbcUrl">jdbc:mysql://XXX
        useUnicode=true&amp;characterEncoding=utf-8&amp;connectTimeout=60000&amp;socketTimeout=60000</property>

        <property name="initialPoolSize">20</property>
        <property name="maxPoolSize">50</property>
        <property name="minPoolSize">5</property>
        <property name="acquireIncrement">2</property>
        <property name="maxIdleTime">10</property>
        <property name="maxStatements">30</property>        
        <property name="idleConnectionTestPeriod">21600</property>
    </default-config>
    <named-config name="myApp">
        <property name="user">YYY</property>
        <property name="password">YYY</property>
        <property name="driverClass">com.mysql.jdbc.Driver</property>
        <property name="jdbcUrl">jdbc:mysql://YYY</property>

        <property name="initialPoolSize">10</property>
        <property name="maxIdleTime">30</property>
        <property name="maxPoolSize">100</property>
        <property name="minPoolSize">10</property>
    </named-config>

</c3p0-config>