java数据库开发之JDBC的完整封装兼容多种数据库

目前此代码我只用过mysql和oracle数据库测试过，但相信其它数据库都是可以的，只要导入你需要操作的数据库jar包，驱动等就可，下面上代码：

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;
 

public class JDBCUtil {
 
	private static String driver = null;
	private static String url = null;
	private static String username = null;
	private static String password = null;
	
	private CallableStatement callableStatement = null;//创建CallableStatement对象   
	private Connection conn = null;
	private PreparedStatement pst = null;
	private ResultSet rst = null;
	
  
  
	public JDBCUtil(String driver,String url ,String username,String password) {
		this.driver = driver;
		this.url = url;
		this.username = username;
		this.password = password;
	}
	
    
  public Connection getConnection() {  
    try {  
    	 // 加载数据库驱动程序  
      try {
				Class.forName(driver);
			} catch (ClassNotFoundException e) {
				System.out.println("加载驱动错误");  
	      System.out.println(e.getMessage()); 
				e.printStackTrace();
			} 
      // 获取连接  
    	conn = DriverManager.getConnection(url, username,  
    			password);  
    } catch (SQLException e) {  
      System.out.println(e.getMessage());  
    }  
    return conn;  
  }  
  
    
  public int executeUpdate(String sql, Object[] params) {  
    // 受影响的行数  
    int affectedLine = 0;  
      
    try {  
      // 获得连接  
      conn = this.getConnection();  
      // 调用SQL   
      pst = conn.prepareStatement(sql);  
 
      // 参数赋值  
      if (params != null) {  
 for (int i = 0; i < params.length; i++) {  
 	pst.setObject(i + 1, params[i]);  
 }  
      }  
      
      // 执行  
      affectedLine = pst.executeUpdate();
  
    } catch (SQLException e) {  
      System.out.println(e.getMessage());  
    } finally {  
      // 释放资源  
      closeAll();  
    }  
    return affectedLine;  
  }  
  
    
  private ResultSet executeQueryRS(String sql, Object[] params) {  
    try {  
      // 获得连接  
      conn = this.getConnection();  
 
      // 调用SQL  
      pst = conn.prepareStatement(sql);  
 
      // 参数赋值  
      if (params != null) {  
 for (int i = 0; i < params.length; i++) {  
 	pst.setObject(i + 1, params[i]);  
 }  
      }  
 
      // 执行  
      rst = pst.executeQuery();  
  
    } catch (SQLException e) {  
      System.out.println(e.getMessage());  
    }   
  
    return rst;  
  }  
    
    
  public Object executeQuerySingle(String sql, Object[] params) {  
    Object object = null;  
    try {  
      // 获得连接  
      conn = this.getConnection();  
 
      // 调用SQL  
      pst = conn.prepareStatement(sql);  
 
      // 参数赋值  
      if (params != null) {  
 for (int i = 0; i < params.length; i++) {  
 	pst.setObject(i + 1, params[i]);  
 }  
      }  
 
      // 执行  
      rst = pst.executeQuery();  
  
      if(rst.next()) {  
 object = rst.getObject(1);  
      }  
 
    } catch (SQLException e) {  
      System.out.println(e.getMessage());  
    } finally {  
      closeAll();  
    }  
  
    return object;  
  }  
  
    
  public List