code: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you 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.
   */
  package org.apache.cxf.ws.security.policy.builders;
  
  import javax.xml.namespace.QName;
  
  import org.w3c.dom.Element;
  import org.w3c.dom.Node;
  
  import org.apache.cxf.ws.security.policy.SP12Constants;
  import org.apache.cxf.ws.security.policy.SPConstants;
  import org.apache.cxf.ws.security.policy.model.Header;
  import org.apache.cxf.ws.security.policy.model.RequiredParts;
  import org.apache.neethi.Assertion;
  import org.apache.neethi.AssertionBuilderFactory;
  import org.apache.neethi.builders.AssertionBuilder;
  
  public class RequiredPartsBuilder implements AssertionBuilder<Element> {
          
      public Assertion build(Element element, AssertionBuilderFactory factory)
          throws IllegalArgumentException {
          RequiredParts requiredParts = new RequiredParts(SP12Constants.INSTANCE);
          
          Node nd = element.getFirstChild();
          while (nd != null) {
              if (nd instanceof Element) {
                  processElement((Element)nd, requiredParts);                
              }
              nd = nd.getNextSibling();
          }
  
          return requiredParts;
      }
         
      public QName[] getKnownElements() {
          return new QName[] {SP12Constants.REQUIRED_PARTS};
      }
  
      private void processElement(Element element, RequiredParts parent) {
          if ("Header".equals(element.getLocalName())) {
  
              String nameAttribute = element.getAttribute(SPConstants.NAME);
              if (nameAttribute == null) {
                  nameAttribute = "";
              }
  
              String namespaceAttribute = element.getAttribute(SPConstants.NAMESPACE);
              if ("".equals(namespaceAttribute)) {
                  throw new IllegalArgumentException(
                      "sp:RequiredParts/sp:Header@Namespace must have a value"
                  );
              }
              parent.addHeader(new Header(nameAttribute, namespaceAttribute));
          }
      }
  }
  