String.format("First {0} and then {1}", "foo", "bar"); //Noncompliant. Looks like there is a confusion with the use of {{java.text.MessageFormat}}, parameters "foo" and "bar" will be simply ignored here String.format("Display %3$d and then %d", 1, 2, 3); //Noncompliant; the second argument '2' is unused String.format("Too many arguments %d and %d", 1, 2, 3); //Noncompliant; the third argument '3' is unused String.format("First Line\n"); //Noncompliant; %n should be used in place of \n to produce the platform-specific line separator String.format("Is myObject null ? %b", myObject); //Noncompliant; when a non-boolean argument is formatted with %b, it prints true for any nonnull value, and false for null. Even if intended, this is misleading. It's better to directly inject the boolean value (myObject == null in this case) String.format("value is " + value); // Noncompliant String s = String.format("string without arguments"); // Noncompliant MessageFormat.format("Result '{0}'.", value); // Noncompliant; String contains no format specifiers. (quote are discarding format specifiers) MessageFormat.format("Result {0}.", value, value); // Noncompliant; 2nd argument is not used MessageFormat.format("Result {0}.", myObject.toString()); // Noncompliant; no need to call toString() on objects java.util.Logger logger; logger.log(java.util.logging.Level.SEVERE, "Result {0}.", myObject.toString()); // Noncompliant; no need to call toString() on objects logger.log(java.util.logging.Level.SEVERE, "Result.", new Exception()); // compliant, parameter is an exception logger.log(java.util.logging.Level.SEVERE, "Result '{0}'", 14); // Noncompliant - String contains no format specifiers. logger.log(java.util.logging.Level.SEVERE, "Result " + param, exception); // Noncompliant; Lambda should be used to differ string concatenation. org.slf4j.Logger slf4jLog; org.slf4j.Marker marker; slf4jLog.debug(marker, "message {}"); slf4jLog.debug(marker, "message", 1); // Noncompliant - String contains no format specifiers. org.apache.logging.log4j.Logger log4jLog; log4jLog.debug("message", 1); // Noncompliant - String contains no format specifiers.