This function is similar to PI Standard Function but it won't throw exception like the standard UDF

subStrings.java

public String subStrings(String FieldValue, String startPos, String endPos, Container container) throws StreamTransformationException{
	String newFieldValue = "";
	try{
		int istartPos = Integer.parseInt(startPos);
		int iendPos = Integer.parseInt(endPos);	
		
		if( startPos.equals("-1") ){ //startPos value is passed as -1 then substring from 0 till the endPos value
			newFieldValue = FieldValue.substring(0,iendPos);
		}else if ( endPos.equals("-1") ){ //endPos value is passed as -1 then substring from startPos till end
			newFieldValue = FieldValue.substring(istartPos);
		}else{
			newFieldValue = FieldValue.substring(istartPos, iendPos); //This is a normal substring with exception block
		}			
	}catch(Exception ee){
		newFieldValue = FieldValue;
	}
	return newFieldValue;
}