Meins

import java.io.*;


public class XMLEncoding {

	public static void main(String[] args) throws FileNotFoundException, IOException {
		File datei = new File("utf-8.xml");
		FileReader leser = new FileReader(datei);
		StringBuffer sequenz = new StringBuffer(100);
		String encoding = "";
		boolean schalter = false;
			 
		for(;;){
			int gelesenInt = leser.read();
			if(gelesenInt == -1 || gelesenInt == 62){break;}			
			sequenz.append((char)gelesenInt);
		}
				
		try{
			encoding = sequenz.substring(30, sequenz.length()-2);
		} catch (StringIndexOutOfBoundsException e){
			schalter = true;
		}
		
		if(schalter){
			encoding = "UTF-8";
			
			
			FileInputStream byteleser = new FileInputStream(datei);
			byte[] barray = new byte[2];
			
			// ersten beiden Bytes einlesen
			byteleser.read(barray);
			
			if(barray[0] == 0x00 && barray[1] == 0x3c){
				encoding = "UTF-16BE";
			}
			if(barray[0] == 0x3c && barray[1] == 0x00){
				encoding = "UTF-16LE";
			}	
		}
		
		System.out.println(encoding);
	}
}