JDBC 连接管理

public class ConnectionUtil {
public static final ThreadLocal tLocalconn = new ThreadLocal();
private static Connection conn = null;
private static Driver driver= null;
/**
* Connection工厂 获取Connection
*/
static {

    try {
        driver = (Driver)Class.forName("org.logicalcobwebs.proxool.ProxoolDriver").newInstance();
        DriverManager.registerDriver(driver);
        conn= DriverManager.getConnection("proxool.pro_pool");
    } catch (Exception e) {
        e.printStackTrace();
    }
}

/**
 * 获取
 */
public static Connection getConnection() {
    Connection connection = (Connection) tLocalconn.get();
    try {
        if (connection ==null) {
            connection = conn;
            tLocalconn.set(conn);
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return connection;
}

/**
 * 关闭
 */
public static void closeConnection() {

    Connection connection = (Connection) tLocalconn.get();
    tLocalconn.set(null);
    try {
        if (connection != null ) {
            connection.close();
        }

    } catch (Exception e) {
        e.printStackTrace();
    }
}

/**
 * 开始事务
 */
public static void beginTransaction() {
    Connection connection = (Connection) tLocalconn.get();
    if (connection != null) {
        try {
            connection.setAutoCommit(false);
            //connection.commit();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}
/**
 * 提交事物
 */
public static void commitTransaction() {
    Connection connection = (Connection) tLocalconn.get();
    if (connection != null) {
        try {
            connection.setAutoCommit(true);
            connection.commit();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

/**
 *回滚
 */
public static void rollbackTransaction() {
    Connection connection = (Connection) tLocalconn.get();
        if (connection != null ) {
            try {
                connection.rollback();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

}

上面这个类是我自己模仿HibernateUtil类，封装的JDBC连接管理类，请问行的通不

进来了，就说一下:
Connection 不要定义为类变量. 这会导致你的Connection对象只初始化一次,也就是说你只会获得一次Connection对象.如果你用这个类会使你的程序只有一条数据库连接.