java (功能篇) java数据库连接

左手的ㄟ右手 2023-10-16 20:28 37阅读 0赞

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){
    		
    	}
    
    
    }