说明：  用 C++ 作为宿主语言完成： Java语言词法分析器的设计和实现 使用DFA实现词法分析器的设计； 实现对Java源程序中注释的过滤； 利用两对半缓冲区从文件中逐一读取单词； 词法分析结果属性字流存放在独立文件(文件名：scanner_output)中； 统计源程序每行单词的个数和整个源文件单词个数； 具有报告词法错误和出错位置（源程序行号和该行字符）的功能；
(Using C++ as the host language to complete: Java language lexical analyzer of the design and implementation of the use of DFA to achieve the design of lexical analyzer the realization of the Notes on the Java source code in the filter the use of two pairs of semi-buffer read from the document the words one by one lexical analysis of flow properties of the word stored in a separate document (file name: scanner_output) in statistical source of the number of words per line and the word number of source files with the report of lexical errors and error location (line number and the source line characters) of the function )