Query regarding implmentation of writeXXX operations in DataOutPutStream

[Vivek Kr Singh]

I am getting familiar serialization API's in JDK. I have a simple question regarding implementation of java.io.DataOutPutStream writeXXX operations.

Here is the implementation for this API

         /**
          * Writes an <code>int</code> to the underlying output stream as four
          * bytes, high byte first. If no exception is thrown, the counter
          * <code>written</code> is incremented by <code>4</code>.
          *
          * @param      v   an <code>int</code> to be written.
          * @exception  IOException  if an I/O error occurs.
          * @see        java.io.FilterOutputStream#out
          */
         public final void writeInt(int v) throws IOException {
             out.write((v >>> 24) & 0xFF);
             out.write((v >>> 16) & 0xFF);
             out.write((v >>>  8) & 0xFF);
             out.write((v >>>  0) & 0xFF);
             incCount(4);
         }   

Why there is a bitwise & with 0xFF ?

Edit : out.write will only write a byte and bitwise & with 0xFF will return a byte