how to create a custom datatype in java?

I want to create an custom datatype in Java,for example datatype Email , that having following method isValidate(String email),isEmailExist(String email),getDomain(String email), get Id(String email),just like Integer class in java.

Integer is a class and I can initialise the object of Integer class as follows:

Integer i = 100;

I created my class Email and I want to initialise it as follows

Email e = "sam";

How can i perform this functionality in my Email class.

import java.util.StringTokenizer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class Email
{
   private String email;
    public Email(String email)
    {
        this.email=email;
    }

Email() {  
}

public Boolean isvalid(String email)
{


String lastToken = null;
   Pattern p = Pattern.compile(".+@.+\.[a-z]+");
   // Match the given string with the pattern
   Matcher m = p.matcher(email);
   // check whether match is found
   boolean matchFound = m.matches();
   StringTokenizer st = new StringTokenizer(email, ".");
   while (st.hasMoreTokens())
   {
      lastToken = st.nextToken();
   }

if (matchFound && lastToken.length() >= 2
      && email.length() - 1 != lastToken.length())
   {
      return true;
   }
   else
      return false;
   }
  public String toString() {
    return email;
    }
}

Thanks