Bug 29003 Preferences 'Output Folder Name' needs to allow '/' in the path [build path]
In the window/preferences/Java/New Project panel, when 'Folders' radio button is set, the 'output folder name' cannot be set to something like 'WEB- INF/classes'. The error message "'/' is an invalid character" appears. However, when setting the output path on the project (project/properties), 'WEB- INF/classes' is allowed, as the '/' is valid. Please change the window/preferences to allow a '/' in output folder name, so this value can be set by default.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/NewJavaProjectPreferencePage.java
String srcName= fSrcFolderNameText.getText();
			String binName= fBinFolderNameText.getText();
			if (srcName.length() + binName.length() == 0) {
				updateStatus(new StatusInfo(IStatus.ERROR,  JavaUIMessages.getString("NewJavaProjectPreferencePage.folders.error.namesempty"))); 
				return;
			}
			IWorkspace workspace= JavaPlugin.getWorkspace();
			IStatus status;
			if (srcName.length() != 0) {
				status= workspace.validateName(srcName, IResource.FOLDER);
				if (!status.isOK()) {
					String message= JavaUIMessages.getFormattedString("NewJavaProjectPreferencePage.folders.error.invalidsrcname", status.getMessage()); 
					updateStatus(new StatusInfo(IStatus.ERROR, message));
					return;
				}
			}
			status= workspace.validateName(binName, IResource.FOLDER);
			if (!status.isOK()) {
				String message= JavaUIMessages.getFormattedString("NewJavaProjectPreferencePage.folders.error.invalidbinname", status.getMessage()); 
				updateStatus(new StatusInfo(IStatus.ERROR, message));
				return;
			}
			IProject dmy= workspace.getRoot().getProject("dmy"); 
			IClasspathEntry entry= JavaCore.newSourceEntry(dmy.getFullPath().append(srcName));
			IPath outputLocation= dmy.getFullPath().append(binName);
			status= JavaConventions.validateClasspath(JavaCore.create(dmy), new IClasspathEntry[] { entry }, outputLocation);
			if (!status.isOK()) {
				updateStatus(status);
				return;
			}