通过统计文件中各字符的出现频率，建立Huffman树，再通过建立的已经Huffman的树，对文件中各字符进行编码，将结果存入新的文件中，然后从文件中读取Huffman编码，进行解码，结果存入新的文件中，并与源文件进行比较。

　　-Through statistical document the frequency of each character, the establishment of Huffman trees, and through the already established Huffman tree, the file encoding of each character, will result in a new file, and then read from the file Huffman coding, the decoding, the results into a new file and compare with the source file.