PDF文件添加水印依赖的itextpdf-5.5.13.jar,以及适用版本的字体包itext-asian-5.2.0.jar解决添加中文水印不能显示的问题。BaseFont.createFont("STSong-Light","UniGB-UCS2-H",BaseFont.NOT_EMBEDDED);时报错:"Font'STSong-Light'with'UniGB-UCS2-H'isnotrecognized."