问题
I have a problem with my code, even though it hasn't been modified in any way. It just suddenly threw this message. As you can see on the left, that they are all in the correct package, and have correct names.
What can I do to fix this problem?
回答1:
Clear the cache to fix it. In Windows, cache is located at:
C:\Users\username\AppData\Local\NetBeans\...
On Linux, cache is at:
/home/username/.cache/netbeans/...
After clearing the cache restart netbeans.
回答2:
If clearing the cache still doesn't work try adding the jar files themselves instead of adding the folder. Looks like a bug in Netbeans. I did it that way and worked like a charm.
回答3:
I had some compiled classes from a JAR which I wanted to include in my project. I created a new package, I added the complied classes in and then got this "package does not exist" error when trying to import the new package.
If you're adding compiled Java classes and getting this error, here's how I solved it:
Create the package
Add a new (empty) Java Class (.java file) to the package, using the same name as the compiled Java class.
At this point, you should see your broken references to "package does not exist" or to the class file you just added are fixed.
Delete the new .java file and NetBeans should still see the package with the newly added classes.
回答4:
I ran into this problem after we moved our NFS mount point containing my root project directory.
It seems there were some references to the old mount point in the .nb-gradle directory.
I closed all the projects in Netbeans and terminated Netbeans. I moved .nb-gradleto hidden.nb-gradle (and .nb-gradle-properties to hidden.nb-gradle-properties for good measure). I restarted NetBeans and reopened the root project (which auto-opened the subprojects).
The does not exist message and all cascaded errors went away. A new .nb-gradle directory was created in the root project directory. The .nb-gradle-properties file was not re-created.
来源：https://stackoverflow.com/questions/35361254/java-netbeans-package-does-not-exist