Java封装JDBC数据库增、删、改、查操作成JAR文件，以供Web工程调用，适用于多种数据库

废话不多说，直接上源代码，最后有使用方法，当然，也可以作为普通公用类使用，只是封装成JAR更方便使用。

package db.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.sql.CallableStatement;  
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 org.json.JSONObject;

/*
 * 说明：封装JDBC数据库增删改查、存储过程
 * 作者：Jiro.Chen
 * 时间：2016-12-12 15:13:54
 * */

public class ConnectionUtil {

    private static String DRIVER = null;  
  
    private static String URL = null;  
  
    private static String USERNAME = null;  
  
    private static String PASSWORD = null;  
  
    private Connection conn = null;  
  
    private PreparedStatement pstmt = null;  
  
    private CallableStatement callableStatement = null;  

    private ResultSet resultSet = null;  
  
    private void init(){
    	 try {   
             Class.forName(DRIVER);  
         } catch (ClassNotFoundException e) {  
             System.out.println("加载驱动错误");
             System.out.println(e.getMessage());  
         }
    }
    
    public ConnectionUtil(String dbParam){
    	String path = getCurrentPath();
    	String filePath = path + "\\db.JSON";
    	
    	String text = null;
    	try{
    		text = this.readFile(new File(filePath));
    		if(text.equals(null) || text.equals("")){
    			filePath = path + "\\db.json";
    			text = this.readFile(new File(filePath));
    			if(text.equals(null) || text.equals("")){
    				System.out.println("找不到指定文件");
    			}
    		}
    	}catch(Exception e){
    		e.printStackTrace();
    	}
    	
    	JSONObject json = new JSONObject(text);
    	JSONObject DB = json.getJSONObject(dbParam);
    	
    	DRIVER = DB.getString("DRIVER");
    	URL = DB.getString("URL");
    	USERNAME = DB.getString("USERNAME");
    	PASSWORD = DB.getString("PASSWORD");
    	
    	this.init();
    }
    
    private String readFile(File file){
    	String text = null;
    	
    	try{
    		if(file.isFile() && file.exists()){
    			InputStreamReader read = new InputStreamReader(new FileInputStream(file),"UTF-8");
    			BufferedReader bufferedReader = new BufferedReader(read);
    			String lineTxt = null;
    			
    			while((lineTxt = bufferedReader.readLine()) != null){
    				text += lineTxt;
    			}
    			read.close();
    		}
    	}catch(Exception e){
    		e.printStackTrace();
    	}
    	
    	return text;
    }
    
    private String getCurrentPath(){
		String rootPath = null;
		
		java.net.URL url = ConnectionUtil.class.getProtectionDomain().getCodeSource().getLocation();
		String filePath = null;
		
		try{
			filePath = java.net.URLDecoder.decode(url.getPath(), "utf-8");
		}catch (Exception e) {
			e.printStackTrace();
		}
		
		if(filePath.endsWith(".jar")){
			filePath = filePath.substring(0, filePath.lastIndexOf("/") + 1);
		}
		
		java.io.File file = new java.io.File(filePath);
		rootPath = file.getAbsolutePath();
		
		rootPath = rootPath.substring(0, rootPath.lastIndexOf("\\"));
		rootPath += "\\classes";
		
		return rootPath;
    }
    
   
    public Connection getConnection(){
        try{
            conn = DriverManager.getConnection(URL, USERNAME,  
                    PASSWORD);
        }catch (SQLException e){  
            System.out.println(e.getMessage());  
        }
        
        return conn;
    }

    public int executeUpdate(String sql, Object[] params){
        int affectedLine = 0;
        
        try{   
            conn = this.getConnection();
   
            pstmt = conn.prepareStatement(sql);  
  
            if (params != null){  
                for (int i = 0; i < params.length; i++){  
                    pstmt.setObject(i + 1, params[i]);
                }  
            }
               
            affectedLine = pstmt.executeUpdate();  
  
        }catch (SQLException e){  
            System.out.println(e.getMessage());  
        }finally {   
            closeAll();  
        }
        
        return affectedLine;  
    }
  
    /** 
     * SQL 查询将查询结果直接放入ResultSet中
     */  
    private ResultSet executeQueryRS(String sql, Object[] params){  
        try{
            conn = this.getConnection();  
                
            pstmt = conn.prepareStatement(sql);  
                
            if (params != null){  
                for (int i = 0; i < params.length; i++){  
                    pstmt.setObject(i + 1, params[i]);  
                }  
            }
            
            resultSet = pstmt.executeQuery();  
  
        }catch (SQLException e){  
            System.out.println(e.getMessage());  
        }
  
        return resultSet;  
    }  
  
    /** 
     * 获取结果集，并将结果放在List中
     */  
    public List