Email validation

[govind soni]

Could anybody help me out to solve the problem for email validation code in java, but without using any java inbuilt method like Macher class etc.

[Rob Spoor]

Why do you want to reinvent the wheel? Whenever I need to validate email addresses I just use javax.mail.internet.InternetAddress.

[govind soni]

:-D :-D Actually this task is asign to me by my manager. so help me out to find out the differ way without any API .

[Tim Moores]

Your manager specifically tells you which classes you can and can not use? Seems like a micro-managing PHB who should get out of your way.

Or you could use the source code of http://commons.apache.org/validator/api-1.4.0/org/apache/commons/validator/routines/EmailValidator.html and pretend you wrote it. Of course, it may well use the class Rob mentioned.

[Wendy Gibbons]

govind soni wrote::-D :-D Actually this task is asign to me by my manager. so help me out to find out the differ way without any API .

Is this an assesment?

[Kotto Bass]

Just use a regular expression. 'google' it

[Jeff Verdegan]

Tim Moores wrote:Your manager specifically tells you which classes you can and can not use? Seems like a micro-managing PHB who should get out of your way.

To me it sounds more like a student falsely claiming that homework is a work assignment. No real manager--even in the worst hellhole outsourcing shop ever--would ever forbid you from using the core API. And if he does (which he never will), you should run as fast as you can. Cleaning toilets in a bus station in the slums of hell would be a better job than that.

[govind soni]

:-D :-D

[govind soni]

Check this code I tried myself but this is not showing correct email validation..... try by yourside and tell me the updates.

import java.lang.*;
import java.io.*;

public class EmailV{
public static void main(String[] args) throws IOException{
System.out.println("Email Validation");
BufferedReader bf =
new BufferedReader(new InputStreamReader(System.in));
System.out.println("Please enter mailid:");
String str1 = bf.readLine();
String myString="str1";
String at="@";
String dot=".";
int lstr = myString.length();
int lat = myString.indexOf("at");
int ldot = myString.indexOf("dot");



{


if (myString.indexOf(at)==-1 || myString.indexOf(at)==0 ||
myString.indexOf(at)==lstr)
System.out.println("Invalid E-mail ID");

else

if (myString.indexOf(dot)==-1 || myString.indexOf(dot)==0 ||
myString.indexOf(dot)==lstr)
System.out.println("Invalid E-mail ID");

else

if (myString.indexOf(at,(lat+1))!=-1)
System.out.println("Invalid E-mail ID");

else

if (myString.substring(lat-1,lat)==dot ||
myString.substring(lat+1,lat+2)==dot)
System.out.println("Invalid E-mail ID");

else

if (myString.indexOf(dot,(lat+2))==-1)
System.out.println("Invalid E-mail ID");

else


if (myString.indexOf(" ")!=-1)
System.out.println("Invalid E-mail ID");

else


System.out.println("valid E-mail ID");
}
}
}

[Henry Wong]

govind soni wrote:Check this code I tried myself but this is not showing correct email validation..... try by yourside and tell me the updates.

import java.lang.*;
import java.io.*;

public class EmailV{
  public static void main(String[] args) throws IOException{
  System.out.println("Email Validation");
  BufferedReader bf = 
new BufferedReader(new InputStreamReader(System.in));
  System.out.println("Please enter mailid:");
  String str1 = bf.readLine();
                String myString="str1"; 
                String at="@";
                String dot=".";
                int lstr = myString.length();
                int lat = myString.indexOf("at");
                int ldot = myString.indexOf("dot");
            

                
{

                 
   if (myString.indexOf(at)==-1 || myString.indexOf(at)==0 ||
                myString.indexOf(at)==lstr)
                   System.out.println("Invalid E-mail ID");
               
                else
                       
                if (myString.indexOf(dot)==-1 || myString.indexOf(dot)==0 ||
                myString.indexOf(dot)==lstr)
                     System.out.println("Invalid E-mail ID");
                  
                else
                       
                if (myString.indexOf(at,(lat+1))!=-1)
                     System.out.println("Invalid E-mail ID");
           
                else
        
                 if (myString.substring(lat-1,lat)==dot || 
                 myString.substring(lat+1,lat+2)==dot)
                     System.out.println("Invalid E-mail ID");
          
                else
                       
                 if (myString.indexOf(dot,(lat+2))==-1)
                     System.out.println("Invalid E-mail ID");
           
                     else
                
                                 
                 if (myString.indexOf(" ")!=-1)
                     System.out.println("Invalid E-mail ID");
                
                 else
                                                      
              
                      System.out.println("valid E-mail ID");
}
  }
}

My first update would be to recommend that you add some debugging messages -- this will enable you to figure out what is going on, and hence, be able to fix it. This way, when you come back here, you can ask specific questions, and with specific details.

My second recommendation is to use the equals() method to compare strings. The "==" operator is used to compare references, which is not what you want.

Henry

[Jeff Verdegan]

Henry Wong wrote:This way, when you come back here, you can ask specific questions, and with specific details.

And when you do come back and ask specific questions with specific details, make sure you're clear about what your actual requirements are. "Valid email address" can have many different interpretations (Read this page for some examples.) and in the absence of specific requirements for your particular case, the only reasonable default would be RFC 2822, and I doubt you actually have to implement conformance to that.