DB数据库语句,在这里直接把老师写的拷过来了,要配置数据库连接池

1.DBUtils

package com.neusoft.trainingcenter.hr.utils;

import java.sql.Connection;

import java.sql.SQLException;

import java.sql.Statement;

import javax.naming.*;

import javax.sql.DataSource;

public class DBUtils {

private static DBUtils dBUtils;

private DataSource dataSource;

private DBUtils() {

try {

Context context = new InitialContext();

dataSource = (DataSource) context.lookup("java:comp/env/jdbc/user");

} catch (NamingException e) {

throw new ServiceException("Error on using naming service", e);

}

}

public static Connection getConnection() {

if (dBUtils == null) {

dBUtils = new DBUtils();

}

try {

Connection conn = dBUtils.dataSource.getConnection();

return conn;

} catch (SQLException e) {

throw new ServiceException("Can not get connection", e);

}

}

public static void beginTransaction(Connection conn) {

try {

conn.setAutoCommit(false);

} catch (SQLException e) {

throw new ServiceException("Can not begin transaction", e);

}

}

public static void commit(Connection conn) {

try {

conn.commit();

conn.setAutoCommit(true);

} catch (SQLException e) {

throw new ServiceException("Can not commit transaction", e);

}

}

public static void rollback(Connection conn) {

try {

conn.rollback();

conn.setAutoCommit(true);

} catch (SQLException e) {

throw new ServiceException("Can not rollback transaction", e);

}

}

public static void closeConnection(Connection conn) {

try {

if (conn != null) {

conn.close();

}

} catch (SQLException e) {

e.printStackTrace();

}

}

public static void closeStatement(Statement stmt) {

try {

if (stmt != null) {

stmt.close();

}

} catch (SQLException e) {

throw new ServiceException("Can not close statement", e);

}

}

}