JVM throws an error when opening some pdf files about pdf-metadata-editor

[tkunse]

After such a long time, I finally realized what's the problem. (Because I myself have written several Java programs too and experienced several problems when trying to distribute. However, I do not upload the code to github for some security reasons.)
This error message is all caused by the encoding. Since I am using this software on Windows, the system's default encoding is not UTF-8. For this reason alone, Java programs cannot perform normally when reading something that is encoded by UTF-8, such as the metadata in PDF files.
So the solution is to add a -Dfile.encoding=UTF-8 to the JVM option. This can solve most problems. However, when a PDF document is protected using permission passwords, exceptions are thrown again. It is not a serious problem then, for I can just remove the passwords and use this tool.
Sorry for the disturbance (if any).