import java.sql.*; import java.io.*; import java.util.regex.*; 
public class test{  public static void main(String[] args){   try{    String s = "";    while(!s.equals("q")){     System.out.print("input:");     DataInputStream in = new DataInputStream(new BufferedInputStream(System.in));     s = in.readLine();     System.out.println("your input is :"+s);     String check = "^([a-z0-9A-Z]+[-|\\.]?)+[a-z0-9A-Z]@([a-z0-9A-Z]+(-[a-z0-9A-Z]+)?\\.)+[a-zA-Z]{2,}$";     Pattern regex = Pattern.compile(check);                 Matcher matcher = regex.matcher(s);                 boolean isMatched = matcher.matches();                 if(isMatched){                  System.out.println("it's a email");              }else{               System.out.println("it's not a email");              }          }         }catch(Exception e){          System.out.println("error"+e.getMessage());      }  }           }  
 
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