When handling a caught exception, two mandatory informations should be logged:
// Noncompliant - exception is lost try { /* ... */ } catch (Exception e) { LOGGER.info("context"); } // Noncompliant - context is required try { /* ... */ } catch (Exception e) { LOGGER.info(e); } // Noncompliant - exception is lost (only message is preserved) try { /* ... */ } catch (Exception e) { LOGGER.info(e.getMessage()); } // Noncompliant - exception is lost try { /* ... */ } catch (Exception e) { throw new RuntimeException("context"); }
try { /* ... */ } catch (Exception e) { LOGGER.info("context", e); } try { /* ... */ } catch (Exception e) { throw new RuntimeException("context", e); }
It is allowed to let the exception propagate.
try { /* ... */ } catch (RuntimeException e) { doSomething(); throw e; } catch (Exception e) { // Conversion into unchecked exception is also allowed throw new RuntimeException(e); }
InterruptedException
, NumberFormatException
, ParseException
and MalformedURLException
exceptions are arguably used to indicate nonexceptional outcomes.
As they are part of Java, developers have no choice but to deal with them. This rule does not verify that those particular exceptions are correctly handled.
int myInteger; try { myInteger = Integer.parseInt(myString); } catch (NumberFormatException e) { // It is perfectly acceptable to not handle "e" here myInteger = 0; }