servlet进行用户登录代码

package com.ken.utils; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.sql.DataSource; import com.mchange.v2.c3p0.ComboPooledDataSource; public class DataSourceUtils { private static DataSource dataSource = new ComboPooledDataSource(); private static ThreadLocal<Connection> tl = new ThreadLocal<Connection>(); // 直接可以获取一个连接池 public static DataSource getDataSource() { return dataSource; } // 获取连接对象 public static Connection getConnection() throws SQLException { Connection con = tl.get(); if (con == null) { con = dataSource.getConnection(); tl.set(con); } return con; } // 开启事务 public static void startTransaction() throws SQLException { Connection con = getConnection(); if (con != null) { con.setAutoCommit(false); } } // 事务回滚 public static void rollback() throws SQLException { Connection con = getConnection(); if (con != null) { con.rollback(); } } // 提交并且 关闭资源及从ThreadLocall中释放 public static void commitAndRelease() throws SQLException { 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() throws SQLException { Connection con = getConnection(); if (con != null) { con.close(); } } public static void closeStatement(Statement st) throws SQLException { if (st != null) { st.close(); } } public static void closeResultSet(ResultSet rs) throws SQLException { if (rs != null) { rs.close(); } } }