## Why is this an issue?

Code is sometimes annotated as deprecated by developers maintaining libraries or APIs to indicate that the method, class, or other programming element is no longer recommended for use. This is typically due to the introduction of a newer or more effective alternative. For example, when a better solution has been identified, or when the existing code presents potential errors or security risks.

Deprecation is a good practice because it helps to phase out obsolete code in a controlled manner, without breaking existing software that may still depend on it. It is a way to warn other developers not to use the deprecated element in new code, and to replace it in existing code when possible.

Deprecated classes, interfaces, and their members should not be used, inherited or extended because they will eventually be removed. The deprecation period allows you to make a smooth transition away from the aging, soon-to-be-retired technology.

Check the documentation or the deprecation message to understand why the code was deprecated and what the recommended alternative is.

    /**
     * @deprecated  As of release 1.3, replaced by {@link #Foo}
     */
    @Deprecated
    public class Fum { ... }

    public class Foo {
      /**
       * @deprecated  As of release 1.7, replaced by {@link #newMethod()}
       */
      @Deprecated
      public void oldMethod() { ... }

      public void newMethod() { ... }
    }

    public class Bar extends Foo {
      public void oldMethod() { ... } // Noncompliant; don't override a deprecated method
    }

    public class Baz extends Fum {  // Noncompliant; Fum is deprecated
      public void myMethod() {
        Foo foo = new Foo();
        foo.oldMethod();  // Noncompliant; oldMethod method is deprecated
      }
    }

## Resources

### Documentation

- CWE - CWE-477 - Use of Obsolete Functions