This rule raises an issue when a finalizer assign `null` to fields of the instance it is called on.

## Why is this an issue?

In the Java object lifecycle, the `finalize` method for an instance is called after the garbage collector has determined that the instance can be removed from the object heap. Therefore, it is unnecessary to implement a finalizer to set instance fields explicitly to `null` to tell the garbage collector that the instance no longer needs them.

In the worst case, implementing `finalize` is even counterproductive because it might accidentally create new references from other (living) objects on the heap to the collectible instance, thus, reviving it.

Important note about finalizers:

There are no guarantees when the Java Runtime will call the `finalize` method or whether it will be called at all.

Using finalizers is, therefore, a bad practice. They should never be used to free resources, such as closing streams, freeing locks, or freeing native system resources. Consider other freeing mechanisms instead, such as an explicit `close`, `unlock`, or `free` method in your class.

## How to fix it

Remove assignments from your finalizer that assign `null` to fields of the instance the finalizer is called on. When this leaves you with an empty finalizer body, remove the finalizer.

### Code examples

#### Noncompliant code example

    public class Foo {
      private String name;

      @Override
      void finalize() {
        name = null;  // Noncompliant, instance will be removed anyway
      }
    }

#### Compliant solution

    public class Foo { // Compliant
      private String name;
    }

## Resources

### Documentation

- Java SE 8 API Specification - Object.finalize

### Articles & blog posts

- Java finalize() – Why We Should Not Use It? - Lokesh Gupta
- A Guide to the finalize Method in Java - Baeldung