通用的Java MySQL JDBC主从分离操作工具类

package com.mms.db;    import java.sql.Connection;  import java.sql.DriverManager;  import java.sql.ResultSet;  import java.sql.ResultSetMetaData;  import java.sql.Statement;  import java.util.ArrayList;  import java.util.HashMap;  import java.util.List;  import java.util.Map;    public  class MySqlDB {   //初始化   private MySqlDB(){}      //参数配置   public static String name= "root";   public static String pass= "root";   public static String driver= "com.mysql.jdbc.Driver";      //主库连接  jdbc:mysql//服务器地址/数据库名 ，后面的2个参数分别是登陆用户名和密码   public static String urlM= "jdbc:mysql://localhost:3306/matoldb?useUnicode=true&characterEncoding=utf-8";    //从库连接  jdbc:mysql//服务器地址/数据库名 ，后面的2个参数分别是登陆用户名和密码   public static String urlS= "jdbc:mysql://localhost:3306/matoldb?useUnicode=true&characterEncoding=utf-8";          //数据库连接、操作、结果集   public static Connection conM;  //主库连接     public static Connection conS;  //从库连接   public static Statement st;     public static ResultSet rs;     public static int isNewDriver;  //是否注册数据库连接驱动类      public static void main(String[] args) {    //System.out.println("#Log ["+MySqlDB.getConnection()+"]");        //MySqlDB.insertOrUpdate("delete from mi_socket where id = 1");        //MySqlDB.getList("SELECT * from mi_socket LIMIT 0,1");    //MySqlDB.getObject("SELECT * from mi_socket where id = 1");   }            /*       * 根据主从库标识，返回相应的主从库连接。 0主库 1从库       */      private synchronized static Connection getConnection(int ms) {            try {           //数据库驱动只注册一次           if(isNewDriver == 0){            Class.forName(driver).newInstance();            isNewDriver = 1;           }                      //从库，进行查询操作           if(ms == 1){            if(conS == null){             conS = DriverManager.getConnection(urlS, name, pass);            }            return conS;           }           //主库，进行增、删、改、(查)操作           else{              if(conM == null){             conM = DriverManager.getConnection(urlM, name, pass);            }            return conM;           }          } catch (Exception e) {               System.out.println("#Error log["+e.getMessage()+"]");          }            //默认主库          return conM;      }                   /*       * 执行一条新增、删除、修改操作        */      public synchronized static int insertOrUpdate(String sql) {         getConnection(0);           int count =0;            try {                st = conM.createStatement();                count = st.executeUpdate(sql);            } catch (Exception e) {             System.out.println("#Error log["+e.getMessage()+"]");           } finally{                try {                    if (st != null) {                        st.close();                        st = null;                    }                    if (conM != null) {                     conM.close();                     conM = null;                    }                } catch (Exception e2) {                 System.out.println("#Error log["+e2.getMessage()+"]");               }            }            return count;        }          /*       * 执行一条查询类SQL，返回多条记录集        */      public synchronized static List<Map> getList(String sql) {         getConnection(1);                    List<Map> list = null;              try {                st = conS.createStatement();                rs = st.executeQuery(sql);                if(rs != null){               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 count = md.getColumnCount(); //返回此 ResultSet 对象中的列数                                     Map map = null;                     list = new ArrayList<Map>();                  while (rs.next()) {                        map = new HashMap();                        for(int i = 1; i <= count; i++) {                        //System.out.println("#Log ["+md.getColumnName(i)+"] ["+rs.getObject(i)+"]");                    map.put(md.getColumnName(i), rs.getObject(i));                        }                        list.add(map);                          }                   }           } catch(Exception e) {             System.out.println("#Error log["+e.getMessage()+"]");            } finally{                try {                    if (st != null) {                        st.close();                        st = null;                    }                    if (rs != null) {                        rs.close();                        rs = null;                    }                } catch (Exception e2) {                 System.out.println("#Error log["+e2.getMessage()+"]");               }            }                     return list;      }              /*       * 执行一条查询类SQL，返回单条记录集        */      public synchronized static Map getObject(String sql) {            getConnection(1);                     Map map = null;          try {                st = conS.createStatement();                rs = st.executeQuery(sql);                if(rs != null){               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 count = md.getColumnCount(); //返回此 ResultSet 对象中的列数                                     map = new HashMap();                       if(rs.next()) {                           for(int i = 1; i <= count; i++) {                        //System.out.println("#Log ["+md.getColumnName(i)+"] ["+rs.getObject(i)+"]");                    map.put(md.getColumnName(i), rs.getObject(i));                        }                             }                   }           } catch (Exception e) {             System.out.println("#Error log["+e.getMessage()+"]");             } finally{                try {                    if (st != null) {                        st.close();                        st = null;                    }                    if (rs != null) {                        rs.close();                        rs = null;                    }                              } catch (Exception e2) {                 System.out.println("#Error log["+e2.getMessage()+"]");                 }            }                     return map;      }    }