MySQL工具类的封装

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**MySQL工具类的封装
核心jar包:mysql-connector-java-5.0.4-bin.jar
package com.lg.mysql.tools;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 DbUtils {    private Connection conn=null; //连接    private Statement stmt = null;//状态    private ResultSet rs = null;//结果集    //获取连接    public void  getConnection(){        try {            //加载驱动            Class.forName("com.mysql.jabc.Driver");            //获取连接                                                                      url                                 user   password            conn = DriverManager.getConnection("jdbc:mysql://localhost:3308/tf_26","root","mysql");            //            stmt = conn.createStatement();        } catch (Exception e) {            e.printStackTrace();        }    }    //添加、修改、删除    public int updatae(String sql){        int reslut = -1;        try {            getConnection();            reslut= stmt.executeUpdate(sql);        } catch (Exception e) {            e.printStackTrace();        }finally{            close();        }        return reslut;    }    //查询    public List<Map<String, String>> query(String sql){        List<Map<String, String>> rsList = new ArrayList<Map<String, String>>();        try {            getConnection();            rs= stmt.executeQuery(sql);            //获取字段名            ResultSetMetaData rsmd = rs.getMetaData();            while(rs.next()){                Map<String,String> rsMap = new HashMap<String, String>();                for(int i=0;i<rsmd.getColumnCount();i++){                    //获取字段名                    String columnName = rsmd.getCatalogName(i);                    //获取字段值                    String columnValue = rs.getString(columnName);                    rsMap.put(columnName, columnValue);                }                rsList.add(rsMap);            }        } catch (Exception e) {            e.printStackTrace();        }finally{            close();        }        return rsList;    }    //分页    public List<Map<String,String>> paging(String sql,int nowPage,int size){        sql = sql + "limit " + (nowPage+1)*size + "," + size;        return query(sql);    }    //关闭    public void close(){        try {            if(rs!=null){                rs.close();            }            if(stmt!=null){                stmt.close();            }            if(conn!=null){                conn.close();            }        } catch (Exception e) {            e.printStackTrace();        }    }}
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