You can filter the Project Explorer view to hide projects, folders, or files that you don't want to see.
To enable or disable filters, open the Select Common Navigator Filters window by clicking the Filters button from the drop-down menu at the top right corner of the view. This window lists the available filters.
On the Select Common Navigator Filters tab, select the check boxes next to the filters you want to enable. For example, when the Closed projects filter is enabled, closed projects are not shown in the Project Explorer view. Other filters can hide empty packages, non-java files, and files with names ending in ".class".
On the Available Extensions and Filters tab, the filters work in the opposite way: the selected check boxes describe the projects, folders, and files that are shown in the Project Explorer view. For example, if you clear the check box next to J2EE Deployment Descriptors, the deployment descriptors are hidden from each project in the view.