Java MySQL(SqlHelper)

1.配置文件为：

driver=com.mysql.jdbc.Driver
url=jdbc\:mysql\://localhost\:3306/user_info
user=root
password=root

2.SqlHelper类为：

package com.mysql.JDBC;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.sql.*;
public class SqlHelper
{
    //定义变量
    private static Connection ct = null;
    //大多数情况下用preparedstatement替代statement
    private static PreparedStatement ps = null;
    private static ResultSet rs = null;  

    //连接数据库的参数
    private static String url = null;
    private static String username =null;
    private static String driver =null;
    private static String passwd =null;  

    private static CallableStatement cs = null;
    public static CallableStatement getCs()
    {
        return cs;
    }
    private static Properties  pp = null;
    private static InputStream fis = null;
    //加载驱动，只需要一次，用静态代码块
    static
    {
        try
        {
            //从dbinfo.properties
            pp = new Properties();
            fis=SqlHelper.class.getClassLoader().getResourceAsStream("config.properties");
            pp.load(fis);
            url = pp.getProperty("url");
            driver = pp.getProperty("driver");
            username = pp.getProperty("user");
            passwd = pp.getProperty("password");  

            Class.forName(driver);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        finally
        {
            try{
            	fis.close();
            	}
            catch(IOException e) {e.printStackTrace();}
            fis = null;//垃圾回收站上收拾
        }  

    }
    //得到连接
    public static Connection getConnection()
        {
            try
            {ct = DriverManager.getConnection(url,username,passwd);}
            catch(Exception e) {e.printStackTrace();}
            return ct;
        }  

//*************callPro1存储过程函数1*************
    public static CallableStatement callPro1(String sql,String[] parameters)
    {
        try{
            ct = getConnection();
            cs = ct.prepareCall(sql);
            if(parameters!=null){
                for(int i=0;i<parameters.length;i++){
                 cs.setObject(i+1,parameters[i]);
                }
            }
            cs.execute();
        }
        catch(Exception e) { e.printStackTrace(); throw new RuntimeException(e.getMessage());}
        finally
        { close(rs,cs,ct);}
        return cs;
    }  

//*******************callpro2存储过程2************************
public static CallableStatement callPro2(String sql,String[] inparameters,
Integer[] outparameters)
{
    try
    {
        ct = getConnection();
        cs = ct.prepareCall(sql);
        if(inparameters!=null)
        {
            for(int i=0;i<inparameters.length;i++)
            {
                cs.setObject(i+1,inparameters[i]);
            }
        }
    //cs.registerOutparameter(2,oracle.jdbc.OracleTypes.CURSOR);
        if(outparameters!=null)
        {
            for(int i=0;i<outparameters.length;i++)
            {
                cs.registerOutParameter(inparameters.length+1+i,outparameters[i]);
            }
        }
        cs.execute();
    }
    catch(Exception e) {
        e.printStackTrace(); throw new RuntimeException(e.getMessage());
    }
    finally
    {  

    }
    return cs;
}  

/**
 *
 * @param sql
 * @param parameters
 * @return
 * @author Cally
 * @date 2017-8-27 上午10:32:00
 * @Description
 * @return ResultSet
 */
    public static ArrayList<Object[]> executeQuery(String sql,String[] parameters)
    {
    	ArrayList<Object[]> list = null;
        try
        {
            ct=getConnection();
            ps=ct.prepareStatement(sql);
            if(parameters!=null)
            {
                for(int i=0;i<parameters.length;i++)
                {
                    ps.setString(i+1,parameters[i]);
                }
            }
            rs = ps.executeQuery();  

            //得到结果集（rs）的结构
            ResultSetMetaData rsmd = rs.getMetaData();

//            if(rs.getRow()!=0)
            	list=new ArrayList<Object[]>();

            //通过rsmd可以得到该结果集有多少列
            int columnNum = rsmd.getColumnCount();  

            //从rs中取出数据，并且封装到ArrayList中
            while (rs.next()) {  

                Object []objects = new Object[columnNum];
                for(int i = 0; i < objects.length; i++) {
                    objects[i] = rs.getObject(i + 1);
                }  

                list.add(objects);
            }
            return list;

        }
        catch(Exception e)
        {
            e.printStackTrace();
            throw new RuntimeException(e.getMessage());
        }
        finally
        {
             close(rs, ps, ct);
        }
    }

    public static Connection getCt()
    {
        return ct;
    }
    public static PreparedStatement getPs()
    {
        return ps;
    }
    public static ResultSet getRs()
    {
        return rs;
    }  

    public static void executeUpdate2(String[] sql,String[][] parameters)
    {
        try
        {
            ct = getConnection();
            ct.setAutoCommit(false);  

            for(int i=0;i<sql.length;i++)
            {  

                if(null!=parameters[i])
                {
                    ps = ct.prepareStatement(sql[i]);
                    for(int j=0;j<parameters[i].length;j++)
                    {
                        ps.setString(j+1,parameters[i][j]);
                    }
                    ps.executeUpdate();
                }  

            }  

            ct.commit();  

        }catch (Exception e)
        {
            e.printStackTrace();
            try
            {
                ct.rollback();
            }
            catch (SQLException e1)
            {
                e1.printStackTrace();
            }
            throw  new RuntimeException(e.getMessage());
        }finally
        {
            close(rs,ps,ct);
        }  

    }  

    //先写一个update、delete、insert
    //sql格式：update 表名 set 字段名 =？where 字段=？
    //parameter神应该是（”abc“,23）
    public static void executeUpdate(String sql,String[] parameters)
    {
        try
        {
            ct=getConnection();
            ps = ct.prepareStatement(sql);
            if(parameters!=null)
            {
                for(int i=0;i<parameters.length;i++)
                {
                    ps.setString(i+1,parameters[i]);
                }  

            }
            ps.executeUpdate();
        }
        catch(Exception e)
        {
            e.printStackTrace();//开发阶段
            //抛出异常
            //可以处理，也可以不处理
            throw new RuntimeException(e.getMessage());
        }
        finally
        {
            close(rs,ps,ct);
        }
    }  

    public static void close(ResultSet rs,Statement ps,Connection ct)
    {
        //关闭资源(先开后关)
        if(rs!=null)
        {
            try
            {
                rs.close();
            }
            catch(SQLException e)
            {
                e.printStackTrace();
            }
            rs=null;
        }
        if(ps!=null)
        {
            try
            {
                ps.close();
            }
            catch(SQLException e)
            {
                e.printStackTrace();
            }
            ps=null;
        }
        if(null!=ct)
        {
            try
            {
                ct.close();
            }
            catch(SQLException e)
            {
                e.printStackTrace();
            }
            ct=null;
        }
    }  

    public static  List<Object> resultSetToList(ResultSet rs) throws java.sql.SQLException {
        if (rs == null)
            return Collections.emptyList();
        ResultSet md = (ResultSet) rs.getMetaData(); //得到结果集(rs)的结构信息，比如字段数、字段名等
        int columnCount = ((ResultSetMetaData) md).getColumnCount(); //返回此 ResultSet 对象中的列数
        List<Object> list = new ArrayList<Object>();
        Map<Object, Object> rowData = new HashMap<Object, Object>();
        while (rs.next()) {
         rowData = new HashMap<Object, Object>(columnCount);
         for (int i = 1; i <= columnCount; i++) {
                 rowData.put(((ResultSetMetaData) md).getColumnName(i), rs.getObject(i));
         }
         list.add(rowData);
        }
        return list;
}
}