Returns true if the specified format name can be read : ImageIO « 2D Graphics « Java Tutorial

1. Java Tutorial
2. 2D Graphics
3. ImageIO

import java.io.File;
import java.util.Iterator;

import javax.imageio.ImageIO;

public class Main {
  public static void main(String[] argv) throws Exception {
    boolean b;

    // Check availability using a format name
    b = canReadFormat("foo"); // false
    b = canReadFormat("gif"); // true
    b = canReadFormat("giF"); // true
    }

  // Returns true if the specified format name can be read
  public static boolean canReadFormat(String formatName) {
    Iterator iter = ImageIO.getImageReadersByFormatName(formatName);
    return iter.hasNext();
  }  
}