JDBC操作MySQL数据

对原始jdbc进行封装

 package com.utils;

 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.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;

 /**
  * DButil.java
  * @author zl
  * @version 1.0
  * 功能介绍：使用jdbc对数据库操作(查询、更新（插入/修改/删除）、批量更新)
  */
 public class DButil {

     private Connection conn = null;            //jdbc的链接
     private PreparedStatement ps = null;    //准备sql

     /**
      * 无参构造方法
      */
     public DButil(){}

     /*
      * @param 无
      * 功能介绍：加载驱动，连接数据库。
      */
     public Connection getConnection(){
         //准备好jdbc文件承载的类
         Properties properties = new Properties();
         try {
             //装载jdbc文件到承载类
             properties.load(DButil.class.getResourceAsStream("jdbc.properties"));
             //取承载类的属性
             String driverClassName = properties.getProperty("driverClassName");    //mysql的驱动
             String url = properties.getProperty("url");    //数据库的url
             String username = properties.getProperty("username");    //数据库的用户名
             String pwd = properties.getProperty("pwd");    //数据库当前用户的密码
             Class.forName(driverClassName);
             conn = DriverManager.getConnection(url,username,pwd);    //获取conn链接
             return conn;
         } catch (Exception e) {
             e.printStackTrace();
         }
         return null;
     }

     /*
      * @param sql,params
      * 功能介绍：更新操作（修改，删除，插入）
      */
     public int executeUpdate(String sql,Object[] params){

         try {
             ps = conn.prepareStatement(sql);
             if(params.length != 0){
                 for(int i=0; i<params.length; i++){
                     ps.setObject(i+1, params[i]);
                 }
             }
             int rows = ps.executeUpdate();
             return rows;
         } catch (Exception e) {
             e.printStackTrace();
         }finally{
             closeUpdate();
         }
         return 0;
     }

     /*
      * @param：
      * 功能介绍：批量更新
      */
     public void batchUpdate(String sql,List<Object[]> list){

          try {
                 ps = conn.prepareStatement(sql);
                 conn.setAutoCommit(false); //关闭mysql自动提交事务
                 //final int batchSize = 1000;    //防止内存溢出
                 //int count = 0;    //记录插入数量
                 int size = list.size();
                 Object[] obj = null;
                 for (int i = 0; i < size; i++) {
                     obj = list.get(i);
                     for (int j = 0; j < obj.length; j++) {
                         ps.setObject(j + 1, obj[j]);
                     }
                     ps.addBatch();
                     /*if(++count % batchSize == 0) {
                         ps.executeBatch();
                         //conn.commit();
                     }*/
                 }
                 ps.executeBatch();
                 conn.commit();
                 conn.setAutoCommit(true);
             } catch (SQLException e) {
                 e.printStackTrace();
                 try {
                     conn.rollback();
                     conn.setAutoCommit(true);
                 } catch (SQLException e1) {
                     e1.printStackTrace();
                 }
             } finally {
                 closeUpdate();    //关闭资源
             }
     }

     /*
      * @param sql,params
      * 功能介绍：查询操作
      */
     public List<Map<String,String>> executeQuery(String sql,Object[] params){

         ResultSet rs = null;
         List<Map<String,String>> list = null;
         try {
             ps = conn.prepareStatement(sql);
             if(params != null){
                 for(int i=0; i<params.length; i++){
                     ps.setObject(i+1,params[i]);
                 }
             }
             rs = ps.executeQuery();
             list = new ArrayList<Map<String,String>>();
             while(rs.next()){    //移动光标，如果新的当前行有效，则返回 true；如果不存在下一行，则返回 false
                 ResultSetMetaData rsmd = rs.getMetaData();
                 Map<String,String> map = new HashMap<String, String>();
                 for(int i=1; i<=rsmd.getColumnCount(); i++){
                     map.put(rsmd.getColumnName(i),rs.getObject(i).toString());
                 }
                 list.add(map);
             }
             return list;

         } catch (Exception e) {
             e.printStackTrace();
         }finally{
             closeQuery(rs);
         }
         return null;
     }

     /*
      * @param 无
      * 功能介绍：关闭更新资源
      */
     public void closeUpdate(){
         try{
             if(ps!=null){
                 ps.close();
             }

             if(conn!=null){
                 conn.close();
             }
         }catch(SQLException e){
             e.printStackTrace();
         }
     }

     /*
      * @param rs
      * 功能介绍：关闭查询资源
      */
     public void closeQuery(ResultSet rs){
         try {
             if(rs!=null){
                 rs.close();
             }

             if(ps!=null){
                 ps.close();
             }

             if(conn!=null){
                 conn.close();
             }
         } catch (SQLException e) {
             e.printStackTrace();
         }
     }

     /*
      * @param: args
      * 功能介绍：测试jdbc
      */
     /*public static void main(String[] args) {

         DButil db = new DButil();
         db.getConnection();
 //        String sql = "select * from cpu2006 where id=?";
 //        Object[] params = new Object[1];
 //        params[0] = 1;
 //        List<Map<String,String>> list = new ArrayList<Map<String,String>>();
 //        list = db.executeQuery(sql, params);
 //        System.out.println(list.toString());
             String sql2 = "insert into cpu2006(hardware_vendor,cores,chips,cores_per_chip,base_copies,result,baseline,publish,sys)values(?,?,?,?,?,?,?,?,?)";
             List<Object[]> inList = new ArrayList<Object[]>();    //需要新增的数据
            Object[] cpu = new Object[]{"1","1","1","1","1","1","1","1","1"};
            inList.add(cpu);
            db.batchUpdate(sql2, inList);
     }*/

 }

附上

jdbc.properties

 driverClassName=com.mysql.jdbc.Driver
 url=jdbc:mysql://localhost:3306/testMysql?useUnicode=true&characterEncoding=utf-8
 username=root
 pwd=root