词频统计工具:由用户指定搜索范围，程序遍历搜索范围中所有文本文件（*.txt），统计文本中所有出现单词的出现次数。遍历之后，计算所有单词的出现频率，将各单词按出现频率由大到小排列汇同其出现频率输出到用户指定的文件中。-Frequency statistical tools: the scope of the search specified by the user, the program searches all traverse text file (*. txt), text statistics for all the occurrences of the word. Traversal, the calculated frequency of occurrence of all words for each of the word according to descending order of frequency of occurrence frequency of operation with its output to user-specified file.