Convert Salesforce's 15 character id to 18 character Id See here for context: http://salesforce.stackexchange.com/questions/1653/what-are-salesforce-ids-composed-of

Convert15To18

// Converts 15 char salesforce id to 18 char id
static String convertto18CharId(String original15charId){
	
	if(original15charId == null || original15charId.isEmpty()) return null;
	original15charId = original15charId.trim();
	if(original15charId.length() != 15) return null;
	
	final String BASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456";
	StringBuilder result = new StringBuilder();
	
	try {
  	for(int i = 0; i < 3; i++){
  		StringBuilder tempString = new StringBuilder(original15charId.substring(i*5, i*5+5));
  		tempString.reverse();
  		String binary = "";
  		for(char ch: tempString.toString().toCharArray()) {
  			binary += Character.isUpperCase(ch) ? '1' : '0';
  		}
  		result.append(BASE.charAt(Integer.parseInt(binary,2)));	
  	}
	} catch(Exception ex) {
		  ex.printStackTrace();
	}
	
	if(result.length() == 0) return null;
	
	return original15charId+result.toString();
	
}