winery/org.eclipse.winery.repository/src/main/java/org/eclipse/winery/repository/JAXBSupport.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012-2013 University of Stuttgart.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * and the Apache License 2.0 which both accompany this distribution,
   6  * and are available at http://www.eclipse.org/legal/epl-v10.html
   7  * and http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Contributors:
  10  *     Oliver Kopp - initial API and implementation
  11  *******************************************************************************/
  12 package org.eclipse.winery.repository;
  13
  14 import javax.xml.bind.JAXBContext;
  15 import javax.xml.bind.JAXBException;
  16 import javax.xml.bind.Marshaller;
  17 import javax.xml.bind.Unmarshaller;
  18
  19 import org.eclipse.winery.common.propertydefinitionkv.WinerysPropertiesDefinition;
  20 import org.eclipse.winery.model.tosca.TDefinitions;
  21 import org.eclipse.winery.repository.backend.MockXMLElement;
  22 import org.eclipse.winery.repository.resources.admin.NamespacesResource;
  23 import org.eclipse.winery.model.selfservice.Application;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26
  27 import com.sun.xml.bind.marshaller.NamespacePrefixMapper;
  28
  29 // if com.sun.xml.bind.marshaller.NamespacePrefixMapper cannot be resolved,
  30 // possibly
  31 // http://mvnrepository.com/artifact/com.googlecode.jaxb-namespaceprefixmapper-interfaces/JAXBNamespacePrefixMapper/2.2.4
  32 // helps
  33 // also com.sun.xml.internal.bind.marshaller.NamespacePrefixMapper could be the
  34 // right package
  35
  36 /**
  37  * Bundles all general JAXB functionality
  38  */
  39 public class JAXBSupport {
  40
  41         private static final Logger logger = LoggerFactory.getLogger(JAXBSupport.class);
  42
  43         // thread-safe JAXB as inspired by https://jaxb.java.net/guide/Performance_and_thread_safety.html
  44         // The other possibility: Each subclass sets JAXBContext.newInstance(theSubClass.class); in its static {} part.
  45         // This seems to be more complicated than listing all subclasses in initContext
  46         public final static JAXBContext context = JAXBSupport.initContext();
  47
  48         private final static PrefixMapper prefixMapper = new PrefixMapper();
  49
  50
  51         /**
  52          * Follows
  53          * https://jaxb.java.net/2.2.5/docs/release-documentation.html#marshalling
  54          * -changing-prefixes
  55          *
  56          * See http://www.jarvana.com/jarvana/view/com/sun/xml/bind/jaxb-impl/2.2.2/
  57          * jaxb-impl-2.2.2-javadoc.jar!/com/sun/xml/bind/marshaller/
  58          * NamespacePrefixMapper.html for a JavaDoc of the NamespacePrefixMapper
  59          */
  60         private static class PrefixMapper extends NamespacePrefixMapper {
  61
  62                 @Override
  63                 public String getPreferredPrefix(String namespaceUri, String suggestion, boolean requirePrefix) {
  64                         if (namespaceUri.equals("")) {
  65                                 return "";
  66                         }
  67
  68                         // this does not work to get TOSCA elements without prefix
  69                         // possibly because the attribute "name" is present without prefix
  70                         //      if (namespaceUri.equals(Namespaces.TOSCA_NAMESPACE)) {
  71                         //              return "";
  72                         //      }
  73
  74                         String prefix = NamespacesResource.getPrefix(namespaceUri);
  75                         return prefix;
  76                 }
  77         }
  78
  79
  80         private static JAXBContext initContext() {
  81                 JAXBContext context;
  82                 try {
  83                         // For winery classes, eventually the package+jaxb.index method could be better. See http://stackoverflow.com/a/3628525/873282
  84                         // @formatter:off
  85                         context = JAXBContext.newInstance(
  86                                         TDefinitions.class, // all other elements are referred by "@XmlSeeAlso"
  87                                         WinerysPropertiesDefinition.class,
  88                                         // for the self-service portal
  89                                         Application.class,
  90                                         // MockXMLElement is added for testing purposes only.
  91                                         MockXMLElement.class);
  92                         // @formatter:on
  93                 } catch (JAXBException e) {
  94                         JAXBSupport.logger.error("Could not initialize JAXBContext", e);
  95                         throw new IllegalStateException(e);
  96                 }
  97                 return context;
  98         }
  99
 100         /**
 101          * Creates a marshaller
 102          *
 103          * @throws IllegalStateException if marshaller could not be instantiated
 104          */
 105         public static Marshaller createMarshaller(boolean includeProcessingInstruction) {
 106                 Marshaller m;
 107                 try {
 108                         m = JAXBSupport.context.createMarshaller();
 109                         // pretty printed output is required as the XML is sent 1:1 to the browser for editing
 110                         m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
 111                         m.setProperty("com.sun.xml.bind.namespacePrefixMapper", JAXBSupport.prefixMapper);
 112                         if (!includeProcessingInstruction) {
 113                                 // side effect of JAXB_FRAGMENT property (when true): processing instruction is not included
 114                                 m.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE);
 115                         }
 116                 } catch (JAXBException e) {
 117                         JAXBSupport.logger.error("Could not instantiate marshaller", e);
 118                         throw new IllegalStateException(e);
 119                 }
 120
 121                 return m;
 122         }
 123
 124         /**
 125          * Creates an unmarshaller
 126          *
 127          * @throws IllegalStateException if unmarshaller could not be instantiated
 128          */
 129         public static Unmarshaller createUnmarshaller() {
 130                 try {
 131                         return JAXBSupport.context.createUnmarshaller();
 132                 } catch (JAXBException e) {
 133                         JAXBSupport.logger.error("Could not instantiate unmarshaller", e);
 134                         throw new IllegalStateException(e);
 135                 }
 136         }
 137
 138 }