jdk URL should and how to close?

Question

I use java.net.URL to fetch html from internet I set keepAlive and maxConnections

System.setProperty("http.keepAlive", "true");
System.setProperty("http.maxConnections","600");

And then I start fetch html from internet with several threads things like:

protected static String content(URLConnection conn) throws IOException {
    try (InputStream in = getInputStream(conn)) {
        //bla bla bla...
        // get bytes from in
        return new String(bytes, charset);
    }
}

But I found when I run this procedure for a while (5-8 hours), target website (for test) is Established 760 connections?

So , should I and how can I close URLConnection manually ?

Answer 1

To be honest, you might try using a Socket/ServerSocket instead of URLConnection - with Sockets, you can close the socket when you so choose, and it gives you a more down-and-dirty control over when to open, close, read, and write to a connection. Check out the API:

http://docs.oracle.com/javase/6/docs/api/java/net/Socket.html

Answer 2

I have never seen a way to close the connection explicitly using its API. However, you can set the connection read timeout using setReadTimeout method. This need to be set before the connection is made.