在通过文件上传之后，运行java程序，突然发现这么一个错误：java.lang.ClassFormatError: Unknown constant tag 0 in class file，通过网上查找，很多人认为是要重新编译，可是按照这个方法重新编译之后还是得到同样的结果！百思不得其解！
最后通过：
Maybe it's yet to appear, but I found (and replied) that it was due to an SCP file transfer (of a binary 'class' file) in ascii mode from Windows to Unix.
(1) I did a hex dump of the files on their respective computers, and the two copies of the same class file differed.
(2) I did the transfer again in binary mode and the class file now works. (and, the two files no longer differ.)
获得答案，就是在上传类文件的时候使用了ASCII的模式，而java编译之后的类文件是需要采用binary模式的，改变上传文件的模式之后问题获得了解决！