Bug 38922 method getNextPage() in JavadocTreeWizardPage unnecessary [Javadoc] [Wizard]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javadocexport/JavadocTreeWizardPage.java
fDocletStatus= new StatusInfo();
					IPath path= new Path(fDestinationText.getText());
					if (Path.ROOT.equals(path) || Path.EMPTY.equals(path)) {
						fDestinationStatus.setError(JavadocExportMessages.getString("JavadocTreeWizardPage.nodestination.error")); 
					}
					File file= new File(path.toOSString());
					if (!path.isValidPath(path.toOSString()) || file.isFile()) {
						fDestinationStatus.setError(JavadocExportMessages.getString("JavadocTreeWizardPage.invaliddestination.error")); 
					}
					if ((path.append("package-list").toFile().exists()) || (path.append("index.html").toFile().exists())) 
						fDestinationStatus.setWarning(JavadocExportMessages.getString("JavadocTreeWizardPage.warning.mayoverwritefiles")); 
					updateStatus(findMostSevereStatus());
				}
				break;
			case TREESTATUS :
				fTreeStatus= new StatusInfo();
				if (fInputGroup.getAllCheckedTreeItems().size() == 0)
					fTreeStatus.setError(JavadocExportMessages.getString("JavadocTreeWizardPage.invalidtreeselection.error")); 
				updateStatus(findMostSevereStatus());
				break;
		} 
	}
	private boolean validDocletPath(String docletPath) {
		StringTokenizer tokens= new StringTokenizer(docletPath, ";"); 
		while (tokens.hasMoreTokens()) {
			File file= new File(tokens.nextToken());
			if (!file.exists())
				return false;
		}
		return true;