1、单词统计。键盘输入一段英文语句，将这段话写入文件file.txt中，然后输出这段话，并且统计语句中英文单词的数目（采用Vector类）以及各单词出现的次数（采用Hashtable类）2、查找替换文本文件的内容。(1)键盘输入文件路径及文件名（2）键盘输入待查找的文本信息和替换的文件(1. Word statistics. Keyboard input a sentence in English, write this sentence into file. txt, and then output this sentence, and statistics the number of words in English (using Vector class) and the number of words (using Hashtable class) 2, find the content of the replacement text file. (1) Keyboard input file path and file name (2) Keyboard input text information to be found and replacement files)