artemis-rest/src/main/java/org/apache/activemq/artemis/rest/ActiveMQ.java

/*
 * 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.activemq.artemis.rest;

import javax.ws.rs.core.MediaType;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.Providers;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Type;

import org.apache.activemq.artemis.api.core.client.ClientMessage;
import org.apache.activemq.artemis.rest.util.HttpMessageHelper;
import org.jboss.resteasy.core.Headers;
import org.jboss.resteasy.spi.ResteasyProviderFactory;
import org.jboss.resteasy.util.GenericType;

public class ActiveMQ {

   /**
    * Sets the message body to a serialized
    * byte array of the object.  HTTP consumers will have to provide an Accept header to marshal the object
    *
    * @param message
    * @param object
    */
   public static void setEntity(ClientMessage message, Serializable object) {
      setEntity(message, object, null);
   }

   /**
    * Sets a message property to be the Content-Type passed in.  Sets the message body to a serialized
    * byte array of the object.
    *
    * @param message
    * @param object
    * @param contentType HTTP Content-Type header
    */
   public static void setEntity(ClientMessage message, Serializable object, String contentType) {
      if (contentType != null)
         message.putStringProperty(HttpHeaderProperty.CONTENT_TYPE, contentType);
      byte[] data;
      try {
         ByteArrayOutputStream baos = new ByteArrayOutputStream(1024);

         ObjectOutputStream oos = new ObjectOutputStream(baos);

         oos.writeObject(object);

         oos.flush();

         data = baos.toByteArray();
      }
      catch (IOException e) {
         throw new RuntimeException(e);
      }

      message.getBodyBuffer().writeInt(data.length);
      message.getBodyBuffer().writeBytes(data);

   }

   public static void setHttpHeader(ClientMessage message, String name, String value) {
      message.putStringProperty(HttpHeaderProperty.toPropertyName(name), value);
   }

   /**
    * Get an HTTP header value from a JMS Message
    *
    * @param message
    * @param name
    * @return the HTTP header String
    */
   public static String getHttpHeader(ClientMessage message, String name) {
      return message.getStringProperty(HttpHeaderProperty.toPropertyName(name));
   }

   /**
    * Extract an object using a built-in RESTEasy JAX-RS MessageBodyReader
    *
    * @param message
    * @param type
    * @return
    */
   public static <T> T getEntity(ClientMessage message, Class<T> type) {
      return getEntity(message, type, null, ResteasyProviderFactory.getInstance());
   }

   /**
    * Extract an object using a built-in RESTEasy JAX-RS MessageBodyReader
    *
    * @param message
    * @param type
    * @param factory
    * @return
    */
   public static <T> T getEntity(ClientMessage message, Class<T> type, ResteasyProviderFactory factory) {
      return getEntity(message, type, null, factory);
   }

   /**
    * Extract an object using a built-in RESTEasy JAX-RS MessageBodyReader
    *
    * @param message
    * @param type
    * @param factory
    * @return
    * @throws UnknownMediaType
    * @throws UnmarshalException
    */
   public static <T> T getEntity(ClientMessage message,
                                 GenericType<T> type,
                                 ResteasyProviderFactory factory) throws UnknownMediaType, UnmarshalException {
      return getEntity(message, type.getType(), type.getGenericType(), factory);
   }

   public static <T> T getEntity(ClientMessage msg, Class<T> type, Type genericType, ResteasyProviderFactory factory) {
      int size = msg.getBodySize();
      if (size <= 0)
         return null;

      byte[] body = new byte[size];
      msg.getBodyBuffer().readBytes(body);

      String contentType = msg.getStringProperty(HttpHeaderProperty.CONTENT_TYPE);
      if (contentType == null) {
         throw new UnknownMediaType("Message did not have a Content-Type header cannot extract entity");
      }
      MediaType ct = MediaType.valueOf(contentType);
      MessageBodyReader<T> reader = factory.getMessageBodyReader(type, genericType, null, ct);
      if (reader == null) {
         throw new UnmarshalException("Unable to find a JAX-RS reader for type " + type.getName() + " and media type " + contentType);
      }

      Providers current = ResteasyProviderFactory.getContextData(Providers.class);
      ResteasyProviderFactory.pushContext(Providers.class, factory);
      try {
         return reader.readFrom(type, genericType, null, ct, new Headers<String>(), new ByteArrayInputStream(body));
      }
      catch (IOException e) {
         throw new RuntimeException(e);
      }
      finally {
         ResteasyProviderFactory.popContextData(Providers.class);
         if (current != null)
            ResteasyProviderFactory.pushContext(Providers.class, current);
      }
   }

   /**
    * Was this ActiveMQ Artemis message generated from a REST call?
    *
    * @param msg
    * @return
    */
   public static boolean isHttpMessage(ClientMessage msg) {
      Boolean aBoolean = msg.getBooleanProperty(HttpMessageHelper.POSTED_AS_HTTP_MESSAGE);
      return aBoolean != null && aBoolean.booleanValue() == true;
   }
}