Analysing the Jersey extended WADL support

package org.glassfish.jersey.examples.extendedwadl;

import org.glassfish.jersey.server.wadl.config.WadlGeneratorConfig;
import org.glassfish.jersey.server.wadl.config.WadlGeneratorDescription;
import org.glassfish.jersey.server.wadl.internal.generators.WadlGeneratorApplicationDoc;
import org.glassfish.jersey.server.wadl.internal.generators.WadlGeneratorGrammarsSupport;
import org.glassfish.jersey.server.wadl.internal.generators.resourcedoc.WadlGeneratorResourceDocSupport;

import java.util.List;

/**
 * This subclass of {@link WadlGeneratorConfig} defines/configures {@link org.glassfish.jersey.server.wadl.WadlGenerator}s
 * to be used for generating WADL.
 *
 * @author Martin Grotzke (martin.grotzke@freiheit.com)
 */
public class SampleWadlGeneratorConfig extends WadlGeneratorConfig {

    @Override
    public List<WadlGeneratorDescription> configure() {
        return generator(WadlGeneratorGrammarsSupport.class)
                .prop("grammarsStream", "application-grammars.xml")
                .prop("overrideGrammars", true)
                .generator(WadlGeneratorApplicationDoc.class)
                .prop("applicationDocsStream", "application-doc.xml")
                .generator(WadlGeneratorResourceDocSupport.class)
                .prop("resourceDocStream", "resourcedoc.xml")
                .descriptions();
    }

}

public class SampleWadlGeneratorConfig extends WadlGeneratorConfig {

    @Override
    public List<WadlGeneratorDescription> configure() {
        return generator(WadlGeneratorGrammarsSupport.class)
                .prop("grammarsStream", "application-grammars.xml")
                .prop("overrideGrammars", true)
//                .generator(WadlGeneratorApplicationDoc.class)
//                .prop("applicationDocsStream", "application-doc.xml")
//                .generator(WadlGeneratorResourceDocSupport.class)
//                .prop("resourceDocStream", "resourcedoc.xml")
                .descriptions();
    }

}

return generator(WadlGeneratorGrammarsSupport.class)
        .prop("grammarsStream", "application-grammars.xml")
        .prop("overrideGrammars", true)

@Override
public ApplicationDescription getApplication(final UriInfo uriInfo, final boolean detailedWadl) {
    final ApplicationDescription applicationDescription = getWadlBuilder(detailedWadl, uriInfo)
            .generate(resourceContext.getResourceModel().getRootResources());
    final Application application = applicationDescription.getApplication();
    for (final Resources resources : application.getResources()) {
        if (resources.getBase() == null) {
            resources.setBase(uriInfo.getBaseUri().toString());
        }
    }
    attachExternalGrammar(application, applicationDescription, uriInfo.getRequestUri());
    return applicationDescription;
}

/**
 * Update the application object to include the generated grammar objects.
 */
private void attachExternalGrammar(
        final Application application,
        final ApplicationDescription applicationDescription,
        URI requestURI) {

    // Massage the application.wadl URI slightly to get the right effect
    //

    try {
        final String requestURIPath = requestURI.getPath();

        if (requestURIPath.endsWith("application.wadl")) {
            requestURI = UriBuilder.fromUri(requestURI)
                    .replacePath(
                            requestURIPath
                                    .substring(0, requestURIPath.lastIndexOf('/') + 1))
                    .build();
        }

        final String root = application.getResources().get(0).getBase();
        final UriBuilder extendedPath = root != null
                ? UriBuilder.fromPath(root).path("/application.wadl/") : UriBuilder.fromPath("./application.wadl/");
        final URI rootURI = root != null ? UriBuilder.fromPath(root).build() : null;

        // Add a reference to this grammar
        //

        final Grammars grammars;
        if (application.getGrammars() != null) {
            LOGGER.info(LocalizationMessages.ERROR_WADL_GRAMMAR_ALREADY_CONTAINS());
            grammars = application.getGrammars();
        } else {
            grammars = new Grammars();
            application.setGrammars(grammars);
        }

        // Create a reference back to the root WADL
        //

        for (final String path : applicationDescription.getExternalMetadataKeys()) {
            final URI schemaURI = extendedPath.clone().path(path).build();
            final String schemaPath = rootURI != null ? requestURI.relativize(schemaURI).toString() : schemaURI.toString();

            final Include include = new Include();
            include.setHref(schemaPath);
            final Doc doc = new Doc();
            doc.setLang("en");
            doc.setTitle("Generated");
            include.getDoc().add(doc);

            // Finally add to list
            grammars.getInclude().add(include);
        }
    } catch (final Exception e) {
        throw new ProcessingException(LocalizationMessages.ERROR_WADL_EXTERNAL_GRAMMAR(), e);
    }
}

for (final String path : applicationDescription.getExternalMetadataKeys()) {
    final URI schemaURI = extendedPath.clone().path(path).build();
    final String schemaPath = rootURI != null ? requestURI.relativize(schemaURI).toString() : schemaURI.toString();

    final Include include = new Include();
    include.setHref(schemaPath);
    final Doc doc = new Doc();
    doc.setLang("en");
    doc.setTitle("Generated");
    include.getDoc().add(doc);

    // Finally add to list
    grammars.getInclude().add(include);
}

/**
 * @return A set of all the external metadata keys
 */
public Set<String> getExternalMetadataKeys() {
    return _externalGrammarDefiniton.map.keySet();
}

private WadlGenerator.ExternalGrammarDefinition _externalGrammarDefiniton;

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 * Copyright (c) 2010-2017 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://oss.oracle.com/licenses/CDDL+GPL-1.1
 * or LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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package org.glassfish.jersey.server.wadl.internal;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.net.URI;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.ProcessingException;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;

import javax.inject.Singleton;
import javax.xml.bind.Marshaller;

import org.glassfish.jersey.server.internal.LocalizationMessages;
import org.glassfish.jersey.server.model.ExtendedResource;
import org.glassfish.jersey.server.wadl.WadlApplicationContext;

import com.sun.research.ws.wadl.Application;

/**
 *
 * @author Paul Sandoz
 */
@Singleton
@Path("application.wadl")
@ExtendedResource
public final class WadlResource {

    public static final String HTTPDATEFORMAT = "EEE, dd MMM yyyy HH:mm:ss zzz";

    private volatile URI lastBaseUri;
    private volatile boolean lastDetailedWadl;

    private byte[] wadlXmlRepresentation;
    private String lastModified;

    @Context
    private WadlApplicationContext wadlContext;


    public WadlResource() {
        this.lastModified = new SimpleDateFormat(HTTPDATEFORMAT).format(new Date());
    }

    private boolean isCached(UriInfo uriInfo, boolean detailedWadl) {
        return (lastBaseUri != null && lastBaseUri.equals(uriInfo.getBaseUri()) && lastDetailedWadl == detailedWadl);
    }

    @Produces({"application/vnd.sun.wadl+xml", "application/xml"})
    @GET
    public synchronized Response getWadl(@Context UriInfo uriInfo) {
        try {
            if (!wadlContext.isWadlGenerationEnabled()) {
                return Response.status(Response.Status.NOT_FOUND).build();
            }

            final boolean detailedWadl = WadlUtils.isDetailedWadlRequested(uriInfo);
            if ((wadlXmlRepresentation == null) || (!isCached(uriInfo, detailedWadl))) {
                this.lastBaseUri = uriInfo.getBaseUri();
                lastDetailedWadl = detailedWadl;
                this.lastModified = new SimpleDateFormat(HTTPDATEFORMAT).format(new Date());

                ApplicationDescription applicationDescription = wadlContext.getApplication(uriInfo,
                        detailedWadl);

                Application application = applicationDescription.getApplication();

                try {
                    final Marshaller marshaller = wadlContext.getJAXBContext().createMarshaller();
                    marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
                    final ByteArrayOutputStream os = new ByteArrayOutputStream();
                    marshaller.marshal(application, os);
                    wadlXmlRepresentation = os.toByteArray();
                    os.close();
                } catch (Exception e) {
                    throw new ProcessingException("Could not marshal the wadl Application.", e);
                }
            }

            return Response.ok(new ByteArrayInputStream(wadlXmlRepresentation)).header("Last-modified", lastModified).build();
        } catch (Exception e) {
            throw new ProcessingException("Error generating /application.wadl.", e);
        }
    }


    @Produces({"application/xml"})
    @GET
    @Path("{path}")
    public synchronized Response getExternalGrammar(
            @Context UriInfo uriInfo,
            @PathParam("path") String path) {
        try {
            // Fail if wadl generation is disabled
            if (!wadlContext.isWadlGenerationEnabled()) {
                return Response.status(Response.Status.NOT_FOUND).build();
            }

            ApplicationDescription applicationDescription =
                    wadlContext.getApplication(uriInfo, WadlUtils.isDetailedWadlRequested(uriInfo));

            // Fail is we don't have any metadata for this path
            ApplicationDescription.ExternalGrammar externalMetadata = applicationDescription.getExternalGrammar(path);

            if (externalMetadata == null) {
                return Response.status(Response.Status.NOT_FOUND).build();
            }

            // Return the data
            return Response.ok().type(externalMetadata.getType())
                    .entity(externalMetadata.getContent())
                    .build();
        } catch (Exception e) {
            throw new ProcessingException(LocalizationMessages.ERROR_WADL_RESOURCE_EXTERNAL_GRAMMAR(), e);
        }
    }

}

ApplicationDescription applicationDescription =
        wadlContext.getApplication(uriInfo, WadlUtils.isDetailedWadlRequested(uriInfo));

// Fail is we don't have any metadata for this path
ApplicationDescription.ExternalGrammar externalMetadata = applicationDescription.getExternalGrammar(path);

final ApplicationDescription applicationDescription = getWadlBuilder(detailedWadl, uriInfo)
        .generate(resourceContext.getResourceModel().getRootResources());

/**
   * Generate WADL for a set of resources.
   *
   * @param resources the set of resources.
   * @return the JAXB WADL application bean.
   */
  public ApplicationDescription generate(List<org.glassfish.jersey.server.model.Resource> resources) {
      Application wadlApplication = _wadlGenerator.createApplication();
      Resources wadlResources = _wadlGenerator.createResources();

      // for each resource
      for (org.glassfish.jersey.server.model.Resource r : resources) {
          Resource wadlResource = generateResource(r, r.getPath());
          if (wadlResource == null) {
              continue;
          }
          wadlResources.getResource().add(wadlResource);
      }
      wadlApplication.getResources().add(wadlResources);

      addVersion(wadlApplication);
      addHint(wadlApplication);

      // Build any external grammars

      WadlGenerator.ExternalGrammarDefinition external =
              _wadlGenerator.createExternalGrammar();
      //

      ApplicationDescription description = new ApplicationDescription(wadlApplication, external);

      // Attach the data to the parts of the model

      _wadlGenerator.attachTypes(description);

      // Return the description of the application

      return description;
  }

/**
 * Build the JAXB model and generate the schemas based on tha data
 *
 * @param extraFiles additional files.
 * @return class to {@link QName} resolver.
 */
private Resolver buildModelAndSchemas(final Map<String, ApplicationDescription.ExternalGrammar> extraFiles) {

    // Lets get all candidate classes so we can create the JAX-B context
    // include any @XmlSeeAlso references.

    final Set<Class> classSet = new HashSet<>(seeAlsoClasses);

    for (final TypeCallbackPair pair : nameCallbacks) {
        final GenericType genericType = pair.genericType;
        final Class<?> clazz = genericType.getRawType();

        // Is this class itself interesting?

        if (clazz.getAnnotation(XmlRootElement.class) != null) {
            classSet.add(clazz);
        } else if (SPECIAL_GENERIC_TYPES.contains(clazz)) {

            final Type type = genericType.getType();
            if (type instanceof ParameterizedType) {
                final Type parameterType = ((ParameterizedType) type).getActualTypeArguments()[0];
                if (parameterType instanceof Class) {
                    classSet.add((Class) parameterType);
                }
            }
        }
    }

    // Create a JAX-B context, and use this to generate us a bunch of
    // schema objects

    JAXBIntrospector introspector = null;

    try {
        final JAXBContext context = JAXBContext.newInstance(classSet.toArray(new Class[classSet.size()]));

        final List<StreamResult> results = new ArrayList<>();

        context.generateSchema(new SchemaOutputResolver() {

            int counter = 0;

            @Override
            public Result createOutput(final String namespaceUri, final String suggestedFileName) {
                final StreamResult result = new StreamResult(new CharArrayWriter());
                result.setSystemId("xsd" + (counter++) + ".xsd");
                results.add(result);
                return result;
            }
        });

        // Store the new files for later use
        //

        for (final StreamResult result : results) {
            final CharArrayWriter writer = (CharArrayWriter) result.getWriter();
            final byte[] contents = writer.toString().getBytes("UTF8");
            extraFiles.put(
                    result.getSystemId(),
                    new ApplicationDescription.ExternalGrammar(
                            MediaType.APPLICATION_XML_TYPE, // I don't think there is a specific media type for XML Schema
                            contents));
        }

        // Create an introspector
        //

        introspector = context.createJAXBIntrospector();

    } catch (final JAXBException e) {
        LOGGER.log(Level.SEVERE, "Failed to generate the schema for the JAX-B elements", e);
    } catch (final IOException e) {
        LOGGER.log(Level.SEVERE, "Failed to generate the schema for the JAX-B elements due to an IO error", e);
    }

    // Create introspector

    if (introspector != null) {
        final JAXBIntrospector copy = introspector;

        return new Resolver() {

            public QName resolve(final Class type) {

                Object parameterClassInstance = null;
                try {
                    final Constructor<?> defaultConstructor =
                            AccessController.doPrivileged(new PrivilegedExceptionAction<Constructor<?>>() {
                                @SuppressWarnings("unchecked")
                                @Override
                                public Constructor<?> run() throws NoSuchMethodException {
                                    final Constructor<?> constructor = type.getDeclaredConstructor();
                                    constructor.setAccessible(true);
                                    return constructor;
                                }
                            });
                    parameterClassInstance = defaultConstructor.newInstance();
                } catch (final InstantiationException | SecurityException | IllegalAccessException
                        | IllegalArgumentException | InvocationTargetException ex) {
                    LOGGER.log(Level.FINE, null, ex);
                } catch (final PrivilegedActionException ex) {
                    LOGGER.log(Level.FINE, null, ex.getCause());
                }

                if (parameterClassInstance == null) {
                    return null;
                }

                try {
                    return copy.getElementName(parameterClassInstance);
                } catch (final NullPointerException e) {
                    // EclipseLink throws an NPE if an object annotated with @XmlType and without the @XmlRootElement
                    // annotation is passed as a parameter of #getElementName method.
                    return null;
                }
            }
        };
    } else {
        return null; // No resolver created
    }
}

public ExternalGrammarDefinition createExternalGrammar() {

     // Right now lets generate some external metadata

     final Map<String, ApplicationDescription.ExternalGrammar> extraFiles = new HashMap<>();

     // Build the model as required
     final Resolver resolver = buildModelAndSchemas(extraFiles);

     // Pass onto the next delegate
     final ExternalGrammarDefinition previous = wadlGeneratorDelegate.createExternalGrammar();
     previous.map.putAll(extraFiles);
     if (resolver != null) {
         previous.addResolver(resolver);
     }

     return previous;
}

public ExternalGrammarDefinition createExternalGrammar() {

    // Right now lets generate some external metadata

    final Map<String, ApplicationDescription.ExternalGrammar> extraFiles = new HashMap<>();

    // Build the model as required
    final Resolver resolver = buildModelAndSchemas(extraFiles);

    // Pass onto the next delegate
    final ExternalGrammarDefinition previous = wadlGeneratorDelegate.createExternalGrammar();
    previous.map.putAll(extraFiles);
    if (resolver != null) {
        previous.addResolver(resolver);
    }

    return previous;
}

ApplicationDescription applicationDescription =
                    wadlContext.getApplication(uriInfo, WadlUtils.isDetailedWadlRequested(uriInfo));

@Override
public ApplicationDescription getApplication(final UriInfo uriInfo, final boolean detailedWadl) {
    final ApplicationDescription applicationDescription = getWadlBuilder(detailedWadl, uriInfo)
            .generate(resourceContext.getResourceModel().getRootResources());
    final Application application = applicationDescription.getApplication();
    for (final Resources resources : application.getResources()) {
        if (resources.getBase() == null) {
            resources.setBase(uriInfo.getBaseUri().toString());
        }
    }
    attachExternalGrammar(application, applicationDescription, uriInfo.getRequestUri());
    return applicationDescription;
}

WadlGenerator.ExternalGrammarDefinition external =
        _wadlGenerator.createExternalGrammar();

final Resolver resolver = buildModelAndSchemas(extraFiles);