public class OutputStreamShiftingProcessing implements Function<OutputStream, OutputStream> {  
  
  
private static final int SHIFT = 2;  
  
  
 @Override  
 public OutputStream apply(OutputStream outputStream) {  
   return new ShiftingOutputStream(outputStream);  
 }  
  
  
 public static class ShiftingOutputStream extends OutputStream {  
  
  
 private final OutputStream outputStream;  
  
  
 public ShiftingOutputStream(OutputStream outputStream) {  
   this.outputStream = outputStream;  
 }  
  
  
 @Override  
 public void write(int b) throws IOException {  
   if (b != -1) {  
     outputStream.write(b + SHIFT);  
   } else {  
     outputStream.write(b);  
   }  
 }  
  
  
 @Override  
 public void close() throws IOException {  
   outputStream.close();  
 }  
 }  
}  

 public class InputStreamShiftingProcessing implements Function<InputStream, InputStream> {  
  
  
 private static final int SHIFT = 2;  
  
  
 @Override  
 public InputStream apply(InputStream inputStream) {  
   return new ShiftingInputStream(inputStream);  
 }  
  
 public static class ShiftingInputStream extends InputStream {  
  
 private final InputStream inputStream;  
  
 public ShiftingInputStream(InputStream inputStream) {  
   this.inputStream = inputStream;  
 }  
  
 @Override  
 public int read() throws IOException {  
   int read = inputStream.read();  
   if (read != -1) {  
     return read - SHIFT;  
   } else {  
     return read;  
   }  
 }  
  
  
 @Override  
 public void close() throws IOException {  
   inputStream.close();  
 }  
 }  
}