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");
  }

Locating this inspection

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UseOfPropertiesAsHashtable

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Settings or Preferences | Editor | Inspections | Java | Probable bugs

Inspection Details
By default bundled with:	IntelliJ IDEA 2024.2, Qodana for JVM 2024.2,
Can be installed with plugin:	Java, 242.22892

Last modified: 11 September 2024