public class FileLog{

	private static class SplitStream extends OutputStream{

		private final OutputStream s1,s2;

		public SplitStream(OutputStream s1, OutputStream s2){
			this.s1=s1;
			this.s2=s2;
		}

		@Override
		public void write(int b) throws IOException{
			s1.write(b);
			s2.write(b);
		}
	}

	static void setUp(){
		try{
			new File("data").mkdirs();
			File logFile=new File("data/log.txt");
			FileOutputStream fileOut=new FileOutputStream(logFile);

			if(logFile.exists()) logFile.delete();
			logFile.createNewFile();

			System.setErr(new PrintStream(new SplitStream(System.err, fileOut)));
			System.setOut(new PrintStream(new SplitStream(System.out, fileOut)));

		}catch(Exception e){
			e.printStackTrace();
		}
	}
}