Question

I want to extract the server name from a string using Substring. I am not sure if I should iterate a loop or with StringTokenizer, indexof, lastindex or what ever.

Basic requirement is, I should use substring()

For example:

 [e-mail]  ,  [e-mail] etc

This goes in paragraph and should print server names like this:

Server names: yahoo,   gmail ... 

Answer 1

String emails = "[e-mail]  ,  [e-mail] ,  [e-mail]";
emails = emails.trim();  // get rid of spaces.
String[] parts = emails.split(",");  // emails array.

for (String email : parts) 
{
    String temp = email.substring(email.indexOf("@") + 1); // e.g. @google.com
    String serverName = temp.substring(0, temp.indexOf("."));  // e.g. google
    System.out.println(serverName);  //prints google
}

Sample Runs (for single inputs):

Input: [e-mail] Output: google

Input: [e-mail] Output: realmadrid

Input: [e-mail] Output: forest

EDIT: If your emails are not separated with commas or any other delimiters, then you can extract individual e-mail addresses with this code:

String emails = "[e-mail]    [e-mail]";
String[] parts = emails.split("\\s+");

Denote that I’m not using trim() this time. After this splitting, you can again use the same for-loop above.