Anonymous class can be replaced with inner class

Reports anonymous classes.

Occasionally replacing anonymous classes with inner classes can lead to more readable and maintainable code. Some code standards discourage anonymous classes.

Example:

  class Example {
    public static void main(String[] args) {
      new Thread() {
        public void run() {
          work()
        }

        private void work() {}
      }.start();
    }
  }

After the quick-fix is applied:

  class Example {
    public static void main(String[] args) {
      new MyThread().start();
    }

    private static class MyThread extends Thread {
      public void run() {
        work();
      }

      private void work() {}
    }
  }

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

AnonymousInnerClass

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Class structure

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection AnonymousInnerClass

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025