Find out if a given string is Salesforce Id in Java

Question

Is there a way(regex or something) to find out if a given string is a Salesforce Id or not? I'm looking for some helper class in Java.

Answer 1

Regex is okay: [A-Za-z0-9]{15}

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

public class IdUtil {
  private static final String INPUT = "00a000000000012";
  public static void main(String[] args) {
    Pattern id = Pattern.compile('[A-Za-z0-9]{15}');
    Matcher matcher = id.matcher(INPUT);
    if (!matcher.find()) System.out.println('Not an Id!');
  }
}

If you use [A-Za-z0-9]{18} to find 18-character Ids (case-insensitive), best to run the checksum as well. You could port this implementation of the algorithm to Java.

Answer 2

Apex Id data type does validate what is set into it, In apex, you could assign a string to an Id type variable. If you put that in a try block and catch StringException the catch block will indicate failure.

String anIdString = 'a05E0000002Ug8U'; //also works with a05E0000002Ug8UIAS
String aString = 'whatever';

Id anId = anIdString;

System.debug(anId);

try {
    anId = aString;
} catch (StringException e) {
    System.debug('tried to assign invalid string to Id and failed');
}
System.debug(anId);

EDIT: If you wanted to access that logic from outside of SFDC, you could write the logic into a custom webservice method. Even though this is a very clean way to do Id datatype checking, it has the downside of consuming a webservice call for very little gain. But it could be scaled perhaps to do the same with an array of strings:

global with sharing class DemoWebService {
webService static Boolean isStringId(String idTestStr) {
    Boolean isId = true;
    Id anId;
    try {
        anId = idTestStr;
    } catch (StringException e) {
        isId = false;
    }
    return isId;
}
}