Your overridden method must have the same return type, though with JDK 1.5+, you have the option of covariance where your overriding method can be a subclass or the root method’ return type.

When overriding a method, be careful to exactly match the method signature, or you will end up just adding another method, rather than replacing the superclass version. You are permitted to widen the scope however, e.g. make your new method public where the original was default.

Using @Override

/**
 * Get String presentation for this Thing object.
 * @return human readable summary of fields in Thing object.
 */
@Override
public String toString()
  {
  return desc + " " + quantity + " " + losses;
  }