问题
My "workspace" folder includes a hidden folder called ".metadata". Is it important to backup this folder regularly?
回答1:
The .metadata folder is an area where Eclipse plug-ins can save any information they want to save. This will include things like your preference setting and the index the Java plug-in uses to find classes and methods quickly.
It also includes the .log file where Eclipse logs errors.
Exactly what is stored there depends on the plug-ins you have installed (one of my plug-ins has a database in the .metadata) so it is a good idea to back it up (along with the projects).
来源：https://stackoverflow.com/questions/19996170/what-is-the-metadata-folder-in-eclipse-workspace