Java tutorial
//package com.java2s; /* * Copyright 2010-2013, CloudBees Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import org.w3c.dom.Document; import javax.annotation.Nonnull; import javax.annotation.Nullable; public class Main { /** * Check that the name of root element of the given {@code document} matches the given {@code expectedRootElementName} * * @param document * @param expectedRootElementName */ public static void checkRootElement(@Nonnull Document document, @Nullable String expectedRootElementName) { if (document.getDocumentElement() == null || expectedRootElementName == null) { return; } else if (!expectedRootElementName.equals(document.getDocumentElement().getNodeName())) { throw new IllegalStateException("Invalid root element '" + document.getDocumentElement().getNodeName() + "', expected '" + expectedRootElementName + "'"); } } }