How to get favicon.ico from a website using Java?

问题

So I'm making an application to store shortcuts to all the user's favorite applications, acting kind of like a hub. I can have support for actual files and I have a .lnk parser for shortcuts. I thought it would be pretty good for the application to support Internet shortcuts, too. This is what I'm doing:

Suppose I'm trying to get Google's icon (http://www.google.com/favicon.ico).

I start out by getting rid of the extra pages (e.g. www.google.com/anotherpage would become www.google.com.
Then, I use ImageIO.read(java.net.URL) to get the Image.

The problem is that ImageIO never returns an Image when I call this method:

String trimmed = getBaseURL(page); //This removes the extra pages
Image icon = null;    
try {
    String fullURLString = trimmed + "/favicon.ico";
    URL faviconURL = new URL(fullURLString);
    icon = ImageIO.read(faviconURL);
} catch (IOException e) {
    e.printStackTrace();
}

return icon;

Now I have two questions:

Does Java support the ICO format even though it is from Microsoft?
Why does ImageIO fail to read from the URL?

Thank you in advance!

回答1:

Try Image4J.

As this quick Scala REPL session shows (paste-able as Java code):

> net.sf.image4j.codec.ico.ICODecoder.read(new java.net.URL("http://www.google.com/favicon.ico").openStream())

res1: java.util.List[java.awt.image.BufferedImage] = [BufferedImage@65712a80: type = 2 DirectColorModel: rmask=ff0000 gmask=ff00 bmask=ff amask=ff000000 IntegerInterleavedRaster: width = 16 height = 16 #Bands = 4 xOff = 0 yOff = 0 dataOffset[0] 0]

UPDATE

To answer your questions: Does Java support ICO? Doesn't seem like it:

> javax.imageio.ImageIO.read(new java.net.URL("http://www.google.com/favicon.ico"))

java.lang.IllegalArgumentException: Empty region!

Why does ImageIO fail to read from the URL? Well, the URL itself seems to work for me, so you may have a proxy/firewall issue, or it could be the problem above.

回答2:

Old post, but for future reference:

I've written a plugin for ImageIO that adds support for .ICO (MS Windows Icon) and .CUR (MS Windows Cursor) formats.

You can get it from GitHub here: https://github.com/haraldk/TwelveMonkeys/

After you have installed the plugin, you should be able to read the icon, using the code in the original post without any modifications.

回答3:

You don't need ImageIO for this. Just copy the bytes, same as for any other static resource.

来源：https://stackoverflow.com/questions/11090508/how-to-get-favicon-ico-from-a-website-using-java

标签

java

image

javax.imageio

ico