SignatureInputStream.java

package ee.sk.digidoc.factory;
import java.io.FilterInputStream;
import java.io.InputStream;
import java.io.IOException;

/**
 * Special input stream used to filter out BOM
 * (byte-order-marks) from the beginning of xml signature
 * or signed doc xml file.
 * @author Veiko Sinivee
 */
public class SignatureInputStream 
	extends FilterInputStream 
{
	boolean bXml;
	
	/**
	 * Constructor for SignatureInputStream
	 * @param in real input stream to be filtered
	 */
	public SignatureInputStream(InputStream in)
	{
		super(in);
		bXml = false;
	}
	
	public int read() throws IOException
	{
		int b = super.read();
		if(!bXml) {
			while(b != '<' && b != -1) 
				b = super.read();
			bXml = true;
		}
		return b;
	}
}