Use of 'Properties' object as a 'Hashtable'

Reports calls to the following methods on java.util.Properties objects:

put()
putIfAbsent()
putAll()
get()

For historical reasons, java.util.Properties inherits from java.util.Hashtable, but using these methods is discouraged to prevent pollution of properties with values of types other than String.

Calls to java.util.Properties.putAll() won't get reported when both the key and the value parameters in the map are of the String type. Such a call is safe and no better alternative exists.

Example:

Object f(Properties props) {
  props.put("hello", "world");
  props.putIfAbsent("hello", "world");
  props.putAll(new HashMap<>());
  return props.get("Hello");
}

After the quick-fix is applied:

Object f(Properties props) {
  props.setProperty("hello", "world");
  props.putIfAbsent("hello", "world");
  props.putAll(new HashMap<>());
  return props.getProperty("hello");
}

Inspection Details
Available in:	IntelliJ IDEA 2023.3, Qodana for JVM 2023.3
Plugin:	Java, 233.SNAPSHOT

Last modified: 13 July 2023