用java把一个GBK编码的文本文件转换为UTF-8编码，输出文本，按行读取文本文件，控制台按行读入字符数据，下载文本数据-A GBK encoded text file using java, be converted to UTF-8 encoding, output text, read text file line by line, the console line read into the character data and download the text data