Reading and Writing Bytes

Usually data is much more complicated than the data for the example program. But the program shows the outer logic that is needed to read most files. Sometimes the data in a file represents something other than a primitive Java type. For example, word processor files contain many bytes that encode fonts, page formats, and special symbols.

The DataOutputStream and DataInputStream classes have several methods for reading and writing single bytes. Here are two of them:

DataOutputStream:
    public final void writeByte(int b) throws IOException

DataInputStream:
    public final int readUnsignedByte() throws IOException

writeByte() writes the least significant byte of its int argument to the output stream. readUnsignedByte() reads a byte from the input stream and puts it in the least significant byte of its return value.