The "UMC Unwanted method calls" group of errors relates to methods such as System.exit() and System.gc() that might be unwanted. Debug print, such as System.out.println() and System.err.println(), might be unwanted as well. A UMC.EXIT warning appears if there is a call to the System.exit method.

Vulnerability and risk

Use of this method should be limited to one occurrence. The exiting of the JVM is an unwanted side effect: it is better to throw an exception or error, and let the caller deal with it.

Example 1

10     String square(String x) {
11         try {
12             int y = Integer.parseInt(x.toLowerCase());
13             return y * y + "";
14         } catch (NumberFormatException e) {
15             e.printStackTrace();
16             System.exit(1);
17             return "";
18         }
19     }

UMC.EXIT is reported for line 16: The System.exit() method call is unwanted