Re: Type safety ... References to generic type Enumeration<E> should be parameterized

From:
Dale King <DaleWKing@gmail.com>
Newsgroups:
comp.lang.java.help
Date:
Wed, 30 Aug 2006 10:26:27 -0400
Message-ID:
<zfudnUp-9OimPWjZnZ2dnUVZ_tKdnZ2d@insightbb.com>
Hendrik Maryns wrote:

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Ian Wilson schreef:

In Eclipse, this code produces a warning at "foo.nextElement()" saying

"Type safety: The method nextElement() belongs to the raw type
Enumeration. References to generic type Enumeration<E> should be
parameterized"

    void listDefaults() {
        UIDefaults uiDefaults = UIManager.getDefaults();
        Enumeration foo = uiDefaults.keys();
        while (foo.hasMoreElements()) {
            Object key = foo.nextElement();
            Object val = uiDefaults.get(key);
            System.out.println("[" + key.toString() + "]:["
                    + (null != val ? val.toString() : "(null)") + "]");
        }
    }

How should I fix this?


By doing as it says:

Enumeration<Object> foo = uiDefaults.keys()

Or have a look at the API of UIDefaults, to see whether it is some more
specific Enumeration (I suppose not).


It's not. UIDefaults is a subclass of Hashtable<Object,Object> (yet
another example of inappropriate use of inheritance instead of composition).

--
  Dale King

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