Binary Huffman Coding

Reading in Binary Files

• Create an instance of a FileInputStream with the file name passed into constructor
• Pass the FileInputStream to the constructor of the BufferedInputStream

int read(byte[] b)

• Attempts to read b.length bytes into b
• Returns total number of bytes read or -1 if nothing was read
• Need to know size of file beforehand
• Useful in current assignment to read in first 4 bytes

int read()

• Reads the next byte from the stream
• Returns the byte value or -1 if the end of the stream has been reached
• Easiest to set up a while loop and continually byte for -1 (similar to BufferedReader example in lab, except we're now checking for -1 instead of null).

Finding an integer from 4 bytes

The Universal Way - Bit Shifting

The Java Way - ByteBuffer

• ByteBuffer API
• [ByteBuffer.wrap(byte[] array)](http://docs.oracle.com/javase/7/docs/api/java/nio/ByteBuffer.html#wrap(byte[]\)) - Returns an instance of a ByteBuffer given an array of bytes
• [ByteBuffer.getInt()](http://docs.oracle.com/javase/7/docs/api/java/nio/ByteBuffer.html#getInt(\)) - Returns the integer value of an instance of a ByteBuffer

Reading Bits

BitReader Object

Querying Specific Bits

Receiving the tree

• http://www2.hawaii.edu/~ztomasze/teaching/ics211/2013sp/lecture/13B.html#(13)

Decoding the Message

Writing Result File

Padding with Zeros

Debugging

Printing a byte a string