1、检查报错日志如下
7、检测class文件代码：ClassLoader classloader = org.apache.poi.poifs.filesystem.POIFSFileSystem.class.getClassLoader();URL res = classloader.getResource( "org/apache/poi/poifs/filesystem/POIFSFileSystem.class");String path = res.getPath();System.out.println("POI Core came from " + path);classloader = org.apache.poi.POIXMLDocument.class.getClassLoader();res = classloader.getResource("org/apache/poi/POIXMLDocument.class");path = res.getPath();System.out.println("POI OOXML came from " + path);classloader = org.apache.poi.hslf.HSLFSlideShow.class.getClassLoader();res = classloader.getResource("org/apache/poi/hslf/HSLFSlideShow.class");path = res.getPath();System.out.println("POI Scratchpad came from " + path);
8、将旧的jar从Java build path中删除掉，把workspace里面的包删了再把project clean一下，然后重新部署。