Comments on: Enumeration and Iterable

By: Andreas

Andreas — Mon, 09 Feb 2009 19:18:16 +0000

Hi Sam, iterating over Properties with your code like this:


                    for (String propertyName : iterate(model.propertyNames())) {
                        properties.add(new PropertiesTreeData(propertyName,
                                model.getProperty(propertyName), modelFile));
                    }

doesn't seem to work for me:

Type mismatch: cannot convert from element type capture#1-of ? to String

My mistake?

By: Sam

Sam — Sun, 25 Nov 2007 19:15:29 +0000

Thanks Stephan… we have something similar in our codebase, but as soon as you don’t have your utility classes (i.e. coding in another project, possibly an open source hobby project) it is a bit of a pain. For completeness, here’s the code we use:-

public static <T> Iterable<T> iterate(final Enumeration<T> en) {
    final Iterator<T> iterator = new Iterator<T>() {
          public boolean hasNext() {  
              return en.hasMoreElements();  
            }
            public T next() {
              return en.nextElement();  
            }
            public void remove() {
              throw new UnsupportedOperationException();  
            }
    };
    return new Iterable<T>() {
        public Iterator<T> iterator() {
            return iterator;
        }
    };
}

By: Stephan Schmidt

Stephan Schmidt — Sun, 25 Nov 2007 19:00:12 +0000

I use

for (ZipEntry entry: iterate(zip.entries())) {
// do stuff
}

with a simple static import. Short, doesn’t create a new list and is less noisy.

http://stephan.reposita.org/archives/2007/11/03/use-java-5-for-with-an-enumertion/

Peace -stephan

— Stephan Schmidt :: stephan@reposita.org Reposita Open Source - Monitor your software development http://www.reposita.org Blog at http://stephan.reposita.org - No signal. No noise.