package com.wdcloud.monitoring.common;    /**     * @Description: TODO     * @date: 2015��11��19�� ����10:23:16     * @version: 1.0     * @update [����YYYY-MM-DD] [���������][�������]     */import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.SQLException;import java.util.ArrayList;import java.util.Collections;import java.util.HashMap;import java.util.List;import java.util.Map;import com.mysql.jdbc.Statement;/** * 连接数据库的工具类,被定义成不可继承且是私有访问 */public final class DBUtils {    private static String url = "jdbc:mysql://localhost:3306/test";    private static String user = "root";    private static String psw = "root";        private static  Connection conn;    private static Statement statement;        static {        try {            Class.forName("com.mysql.jdbc.Driver");        } catch (ClassNotFoundException e) {            e.printStackTrace();            throw new RuntimeException(e);        }    }        private DBUtils() {            }        /**     * 获取数据库的连接     * @return conn     */    public static Connection getConnection() {        if(null == conn) {            try {                conn = DriverManager.getConnection(url, user, psw);            } catch (SQLException e) {                e.printStackTrace();                throw new RuntimeException(e);            }        }        return conn;    }        public static Statement getStatement(){        if(null == statement){            try{                statement = (Statement) DBUtils.getConnection().createStatement();            }catch (SQLException e) {                e.printStackTrace();                throw new RuntimeException(e);            }        }        return statement;    }        /**     * 释放资源     * @param conn     * @param pstmt     * @param rs     */    public static void closeResources(Connection conn,PreparedStatement pstmt,ResultSet rs) {        if(null != rs) {            try {                rs.close();            } catch (SQLException e) {                e.printStackTrace();                throw new RuntimeException(e);            } finally {                if(null != pstmt) {                    try {                        pstmt.close();                    } catch (SQLException e) {                        e.printStackTrace();                        throw new RuntimeException(e);                    } finally {                        if(null != conn) {                            try {                                conn.close();                            } catch (SQLException e) {                                e.printStackTrace();                                throw new RuntimeException(e);                            }                        }                    }                }            }        }    }        /**     *          * @Description: TODO 将ResultSet转成list         * @date: 2015年11月19日 下午2:08:25         * @version: 1.0         * @param rs         * @return         * @throws java.sql.SQLException             * @List          * @update [日期YYYY-MM-DD] [更改人姓名][变更描述]     */    public static List resultSetToList(ResultSet rs) throws java.sql.SQLException {           if (rs == null)               return Collections.EMPTY_LIST;           ResultSetMetaData md = rs.getMetaData(); //得到结果集(rs)的结构信息，比如字段数、字段名等           int columnCount = md.getColumnCount(); //返回此 ResultSet 对象中的列数           List list = new ArrayList();           Map rowData = new HashMap();           while (rs.next()) {            rowData = new HashMap(columnCount);            for (int i = 1; i <= columnCount; i++) {                    rowData.put(md.getColumnName(i), rs.getObject(i));            }            list.add(rowData);           }           return list;   }    }