java (功能篇) java数据库连接

package com.emc.database; 
 
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.PreparedStatement; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.text.SimpleDateFormat; 
import java.util.Date; 
import java.util.List; 
 
import com.emc.model.DyLun; 
import com.emc.service.DyLunService; 
 
 
 
public class DataBase { 
	private static final String DBDRIVER="com.mysql.jdbc.Driver";//驱动类类名 
 
	private static final String DBNAME="iiiis";//数据库名 
 
	private static final String DBURL="jdbc:mysql://192.168.0.32:3306/"+DBNAME;//连接URL 
 
	private static final String DBUSER="root";//数据库用户名 
 
	private static final String DBPASSWORD="Vixuan724";//数据库密码 
 
	private static Connection conn=null; 
 
	private static PreparedStatement ps=null; 
 
	private static ResultSet rs=null; 
	 
	//获取数据库连接 
 
	public static Connection getConnection(){ 
 
	try{ 
 
	Class.forName(DBDRIVER);//注册驱动 
 
	conn=DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD);//获得连接对象 
	 
	System.out.println("数据库连接成功!"); 
 
	}catch(ClassNotFoundException e){//捕获驱动类无法找到异常 
 
	e.printStackTrace(); 
 
	}catch(SQLException e){//捕获SQL异常 
 
	e.printStackTrace(); 
 
	} 
 
	return conn; 
 
	} 
	 
	 
	//查询数据 
 
	public static ResultSet select(String sql) throws Exception{ 
 
	try{ 
	if(conn == null || conn.isClosed() == true) 
	conn=getConnection(); 
 
	ps=conn.prepareStatement(sql); 
 
	rs=ps.executeQuery(sql); 
 
	return rs; 
 
	}catch(SQLException sqle){ 
 
	throw new SQLException("select data Exception: "+sqle.getMessage()); 
 
	}catch(Exception e){ 
 
	throw new Exception("System error: "+e.getMessage()); 
 
	} 
 
	} 
	 
	//插入数据 
 
	public static int insert(String sql)throws Exception{ 
 
	int num=0;//计数 
 
	try{ 
    if(conn == null || conn.isClosed() == true) 
	conn=getConnection(); 
 
	ps=conn.prepareStatement(sql); 
 
	num=ps.executeUpdate(); 
 
	}catch(SQLException sqle){ 
 
	throw new SQLException("insert data Exception: "+sqle.getMessage()); 
 
	}finally{ 
 
	try{ 
 
	if(ps!=null){ 
 
	ps.close(); 
 
	} 
 
	}catch(Exception e){ 
 
	throw new Exception("ps close exception: "+e.getMessage()); 
 
	} 
 
	try{ 
 
	if(conn!=null){ 
 
	conn.close(); 
 
	} 
 
	}catch(Exception e){ 
 
	throw new Exception("conn close exception: "+e.getMessage()); 
 
	} 
 
	} 
 
	return num; 
 
	} 
	 
	 
	 
	//删除数据 
 
	public int delete(String sql)throws Exception{ 
 
	int num=0;//计数 
 
	try{ 
    if(conn == null || conn.isClosed() == true) 
	conn=getConnection(); 
 
	ps=conn.prepareStatement(sql); 
 
	num=ps.executeUpdate(); 
 
	}catch(SQLException sqle){ 
 
	throw new SQLException("delete data Exception: "+sqle.getMessage()); 
 
	}finally{ 
 
	try{ 
 
	if(ps!=null){ 
 
	ps.close(); 
 
	} 
 
	}catch(Exception e){ 
 
	throw new Exception("ps close Exception: "+e.getMessage()); 
 
	} 
 
	try{ 
 
	if(conn!=null){ 
 
	conn.close(); 
 
	} 
 
	}catch(Exception e){ 
 
	throw new Exception("conn close Exception: "+e.getMessage()); 
 
	} 
 
	} 
 
	return num; 
 
	} 
	 
	//修改数据 
 
	public static int update(String sql)throws Exception{ 
 
	int num=0;//计数 
 
	try{ 
	if(conn == null || conn.isClosed() == true) 
	conn=getConnection(); 
 
	ps=conn.prepareStatement(sql); 
 
	num=ps.executeUpdate(); 
 
	}catch(SQLException sqle){ 
 
	throw new SQLException("update data Exception: "+sqle.getMessage()); 
 
	}finally{ 
 
	try{ 
 
	if(ps!=null){ 
 
	ps.close(); 
 
	} 
 
	}catch(Exception e){ 
 
	throw new Exception("ps close Exception: "+e.getMessage()); 
 
	} 
 
	try{ 
 
	if(conn!=null){ 
 
	conn.close(); 
 
	} 
 
	}catch(Exception e){ 
 
	throw new Exception("conn close Excepiton: "+e.getMessage()); 
 
	} 
 
	} 
 
	return num; 
 
	} 
	 
	 
	public static void main(String[] args){ 
		 
	} 
 
 
}