Bug 11317 Won't export some files to .jar.
Create a new java project called "Foo". In the file system, create a folder named "Foo scripts", and in this folder create a file named "foo.txt". Drag this folder into the eclipse packages view and add it to the "Foo" project. Now try to export the project "Foo" to a .jar file. Only the manifest file shows up, even if the file "foo.txt" is checked!
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarFileExportOperation.java
map.put(javaName, classFiles);
					}
					((ArrayList)classFiles).add(classFile);
				}
			}		
		}
		return map;
	}
	/**
	 * Creates a file resource handle for the file with the given workspace path.
	 * This method does not create the file resource; this is the responsibility
	 * of <code>createFile</code>.
	 *
	 * @param filePath the path of the file resource to create a handle for
	 * @return the new file resource handle
	 * @see #createFile
	 */
	protected IFile createFileHandle(IPath filePath) {
		if (filePath.isValidPath(filePath.toString()) && filePath.segmentCount() >= 2)
			return JavaPlugin.getWorkspace().getRoot().getFile(filePath);
		else
			return null;
	}
	/**
	 * Creates a folder resource handle for the folder with the given workspace path.
	 *
	 * @param folderPath the path of the folder to create a handle for
	 * @return the new folder resource handle
	 */
	protected IFolder createFolderHandle(IPath folderPath) {