oracle_connection

package oracle_jdbc_connection;
import java.sql.*;

public class ConnOracle
...{
    Connection conn;
    Statement stmt;
    ResultSet rs;
    String url="jdbc:oracle:thin:@127.0.0.1:1521:oracle";    
    
    /**//*public static void main(String[] args) throws Exception
    {
        ConnOracle c1=new ConnOracle();
        ResultSet rs=c1.query("select * from customer_info");
        while(rs!=null&&rs.next())
        {
            System.out.println(rs.getString(0));        
        }
            
    }*/

    public ConnOracle()
    ...{
        try...{
                Class.forName("oracle.jdbc.driver.OracleDriver");
                
            }    
        catch(ClassNotFoundException ex)
        ...{ex.printStackTrace();}
    }
    public ResultSet query(String sql)
    ...{
        try
        ...{  
            conn=DriverManager.getConnection(url,"chai","chai");
            if(conn==null)...{
                System.out.println(" *********连接失败，请检查*********");
            }else...{
                System.out.println(" *********连接成功*********");
                stmt=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);    
                rs=stmt.executeQuery(sql);
            }            
            }
          catch(SQLException ex)
            ...{System.out.println("连接失败");ex.printStackTrace();}//}    
            return rs;    
        }
    public int update(String sql)
    ...{   
        int at=0;
        try
        ...{
            conn=DriverManager.getConnection(url,"chai","chai");
            stmt=conn.createStatement();
            at=stmt.executeUpdate(sql);
            conn.close();
            
            }
          catch(Exception ex)
            ...{ex.printStackTrace();}    
          return at;
              
    }
    public void close()...{
     try...{
        
         if(rs!=null)...{
            rs.close();            
            }
         if(stmt!=null)...{
            stmt.close();
            }
         if(conn!=null)...{
            conn.close();
            }
        
        }catch(Exception ex)
        ...{
            ex.printStackTrace();
        }

    }    
        
}