checkname.java

一本jsp自学教材

package test;
import java.sql.*;
public class CheckName{
  ResultSet rs=null;
  String tableName="user";  
  public CheckName(){}  
  public boolean UserExist(String user)
   {
     boolean flag=false;
     try{
      DBConn dbc=new DBConn();
      String sql="SELECT * FROM "+tableName+" WHERE username='"+user+"'";
      rs=dbc.query(sql); 
      if(rs.next())
       flag=true;      
      rs.close();
    }
    catch(Exception e)
    {
      System.out.print(e.toString()); 
    } 
    return flag;
  }
 
}