PDFFileConstruction

说明：  这是一篇有关pdf文件生成的，最起码的几行代码，没有用IText文件，对于pdf文件有一定的了解，才能总结出来的
(This is an article on the pdf file generated, at least a few lines of code, there is no document with iText for pdf file has a certain degree of understanding, can be summed up)