Are all final class immutable?

Question

Are all final classes in Java immutable. String and Integer both are final classes and both are immutable i beleive.

Accepted Answer

No - a final class means you cannot inherit from it. It has nothing to do with mutability. The following class is final yet mutable:

```
public final class FinalMutable {
  int value;
  public void setValue(int v) { value=v; }
  public int getValue() { return value; }
}
```

Solution