C3P0数据库Jar包的使用

<?xml version="1.0" encoding="UTF-8"?>  
<c3p0-config>  
    <!-- 数据库连接池 -->  
    <default-config>  
        <property name="user">root</property>  
        <property name="password">admins</property>  
        <property name="driverClass">com.mysql.jdbc.Driver</property>  
        <property name="jdbcUrl">jdbc:mysql:///shop</property>  
    </default-config>   
</c3p0-config>   

packagecom.shop.utils;

importcom.mchange.v2.c3p0.ComboPooledDataSource;

importjavax.sql.DataSource;
importjava.sql.Connection;
importjava.sql.ResultSet;
importjava.sql.SQLException;
importjava.sql.Statement;

/*** 数据库连接工具
 */
public classDataSourceUtils {

    private static DataSource dataSource = newComboPooledDataSource();

    private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>();

    //直接可以获取一个连接池
    public staticDataSource getDataSource() {
        returndataSource;
    }

    //获取连接对象
    public static Connection getConnection() throwsSQLException {
        Connection con =tl.get();
        if (con == null) {
            con =dataSource.getConnection();
            tl.set(con);
        }
        returncon;
    }

    //开启事务
    public static void startTransaction() throwsSQLException {
        Connection con =getConnection();
        if (con != null) {
            con.setAutoCommit(false);
        }
    }

    //事务回滚
    public static void rollback() throwsSQLException {
        Connection con =getConnection();
        if (con != null) {
            con.rollback();
        }
    }

    //提交并且关闭资源及从ThreadLocal中释放
    public static void commitAndRelease() throwsSQLException {
        Connection con =getConnection();
        if (con != null) {
            con.commit(); //事务提交
            con.close();//关闭资源
            tl.remove();//从线程绑定中移除
}
    }

    //关闭资源方法
    public static void closeConnection() throwsSQLException {
        Connection con =getConnection();
        if (con != null) {
            con.close();
        }
    }

    public static void closeStatement(Statement st) throwsSQLException {
        if (st != null) {
            st.close();
        }
    }

    public static void closeResultSet(ResultSet rs) throwsSQLException {
        if (rs != null) {
            rs.close();
        }
    }

}

//查询商品所有分类  
public List<Category> findAllCategory() throwsSQLException {  
　　QueryRunner runner=newQueryRunner(DataSourceUtils.getDataSource());  
　　String sql="select * from category";  
　　return runner.query(sql,new BeanListHandler<Category>(Category.class));  
}  

//添加商品分类  
public void saveProductCategory(Category category) throwsSQLException{  
    QueryRunner runner=newQueryRunner(DataSourceUtils.getDataSource());  
    String sql="insert into category values(?,?)";  
    runner.update(sql,category.getCid(),category.getCname());  
}