How to set Eclipse project as read-only?

If all else fails just use the operating system to set the project folder as read only. Eclipse will prompt you if you try to modify a read only file.

In Eclipse release 4.5.1 ("Mars"; and probably earlier releases), you can change multiple files by selecting the "src" folder and going to Properties>Resource>; then change the "Write" column under "Permissions".

In newer versions of Eclipse, you can find the option read-only under "Attributes", in Properties>Resource>;.

I don´t think Eclipse has that functionality built in. It just uses the files on the filesystem.

I think you have to do that in the filesystem of the particular OS you are using.