public Object apply()

in metron-stellar/stellar-common/src/main/java/org/apache/metron/stellar/dsl/functions/StringFunctions.java [343:380]

• 37 lines of code
• 15 McCabe index (conditional complexity)

    public Object apply(List<Object> strings) {

      if(strings == null || strings.size() < 2 ) {
        throw new IllegalArgumentException("SUBSTRING requires (at least) 2 arguments: the input and the start position (inclusive)");
      }
      Object varObj = strings.get(0);
      if(varObj != null && !(varObj instanceof String)) {
        throw new IllegalArgumentException("SUBSTRING input must be a String");
      }
      String var = varObj == null?null: (String) varObj;
      Object startObj = strings.get(1);
      if(startObj != null && !(startObj instanceof Number)) {
        throw new IllegalArgumentException("SUBSTRING start must be an Number");
      }
      Integer start = startObj == null?null:((Number)startObj).intValue();
      Integer end = null;
      if(strings.size() > 2) {
        Object endObj = strings.get(2);
        if(endObj != null && !(endObj instanceof Number)) {
          throw new IllegalArgumentException("SUBSTRING end must be an Number");
        }
        end = endObj == null ? null : ((Number) endObj).intValue();
      }
      if(var == null || start == null) {
        return null;
      }
      else if(var.length() == 0) {
        return var;
      }
      else {
        if(end == null) {
          return var.substring(start);
        }
        else {
          return var.substring(start, end);
        }
      }
    }