Is it possible to implement an interface inside a constructor?

The question may sees to be senseless. But could anybody clarify me the bit of coding that i have attatched with this question. I'm in a college project related to parsing. So i was refering HtmlCleaner. I got stucked with this coding.

final CleanerProperties props = new CleanerProperties();
final HtmlCleaner htmlCleaner = new HtmlCleaner(props);
final SimpleHtmlSerializer htmlSerializer = 
    new SimpleHtmlSerializer(props);

// make 10 开发者_StackOverflowthreads using the same cleaner and the same serializer 
for (int i = 1; i <= 10; i++) {
    final String url = "http://search.eim.ebay.eu/Art/2-1/?en=100&ep=" + i;
    final String fileName = "c:/temp/ebay_art" + i + ".xml";
    new Thread(new Runnable() {
        public void run() {
            try {
                TagNode tagNode = htmlCleaner.clean(new URL(url));
                htmlSerializer.writeToFile(tagNode, fileName, "utf-8");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();
}

Can we implement an interface inside a constructor?(Thread class,Runnable interface).Could anybody help me to understand the concept behind it or suggest some articles to study that concept? Thanks in advance...

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You're declaring an anonymous class that "inherits from" (or implements, in this case) a Runnable.

The Thread is just using an existing Thread constructor (one that accepts a Runnable). Anonymous classes are part of Java (and have been for a long time): http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#252986

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In your example, you don't create an interface inside a constructor.

The snippet shows the implementation of an anonymous subclass of Runnable. anonymous because the type of this class simply has no name.

The new Runnable(... statement creates a reference to an instance of that anonymous class and that reference is passed to the constructor Thread(Runnable r).

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Note - we can do the same in three steps, which is a little easier to understand:

// create an anonymous implementation of Runnable
Runnable r = new Runnable() {
     @Override
     public void run() {
       // the run implementation
     }
   };

// create a Thread
Thread t = new Thread(r);

// start the Thread -> will call the run method from the Runnable
t.start();

---

that's an anonymous class. refer : http://ssmela.googlepages.com/AnonymousClassesinJava.pdf

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The command new can be used along with an interface only in a situation like this, where you immediately define the methods.

---

new Thread(new Runnable() {
    public void run() {
        try {
            TagNode tagNode = htmlCleaner.clean(new URL(url));
            htmlSerializer.writeToFile(tagNode, fileName, "utf-8");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}).start();

new Runnable() {...} is declaring an Anonymous Inner Classes.