001/*
002 * (C) Copyright 2006-2017 Nuxeo (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bstefanescu
018 */
019package org.nuxeo.ecm.webengine.jaxrs;
020
021import java.io.IOException;
022import java.util.HashMap;
023import java.util.Map;
024import java.util.Set;
025
026import javax.ws.rs.core.Application;
027
028import org.osgi.framework.Bundle;
029
030/**
031 * A wrapper for a JAX-RS application fragment declared in manifest. The fragment application will be added to the
032 * target host application.
033 *
034 * @author <a href="mailto:[email protected]">Bogdan Stefanescu</a>
035 */
036public class ApplicationFragment extends Application {
037
038    protected final String hostName;
039
040    protected final Bundle bundle;
041
042    protected final Map<String, String> attrs;
043
044    protected String appClass;
045
046    private volatile Application app;
047
048    public Application getApplication() {
049        return app;
050    }
051
052    public static Map<String, String> createAttributes(String hostName) {
053        Map<String, String> attrs = new HashMap<>();
054        if (hostName != null) {
055            attrs.put("host", hostName);
056        }
057        return attrs;
058    }
059
060    public ApplicationFragment(Bundle bundle, String appClass) {
061        this(bundle, appClass, (String) null);
062    }
063
064    public ApplicationFragment(Bundle bundle, String appClass, String host) {
065        this(bundle, appClass, createAttributes(host));
066    }
067
068    public ApplicationFragment(Bundle bundle, String appClass, Map<String, String> attrs) {
069        this.bundle = bundle;
070        this.appClass = appClass;
071        this.attrs = attrs;
072        String host = attrs.get("host");
073        this.hostName = host == null ? "default" : host;
074    }
075
076    protected synchronized void createApp() {
077        try {
078            Object obj = bundle.loadClass(appClass).newInstance();
079            if (obj instanceof ApplicationFactory) {
080                app = ((ApplicationFactory) obj).getApplication(bundle, attrs);
081            } else if (obj instanceof Application) {
082                app = (Application) obj;
083            } else {
084                throw new IllegalArgumentException("Expecting an Application or ApplicationFactory class: " + appClass);
085            }
086        } catch (ReflectiveOperationException | IOException e) {
087            String msg = "Cannot instantiate JAX-RS application " + appClass + " from bundle "
088                    + bundle.getSymbolicName();
089            throw new RuntimeException(msg, e);
090        }
091    }
092
093    public synchronized void reload() {
094        app = null;
095    }
096
097    public Bundle getBundle() {
098        return bundle;
099    }
100
101    public Map<String, String> getAttrs() {
102        return attrs;
103    }
104
105    public String getHostName() {
106        return hostName;
107    }
108
109    public Application get() {
110        if (app == null) {
111            createApp();
112        }
113        return app;
114    }
115
116    @Override
117    public Set<Class<?>> getClasses() {
118        return get().getClasses();
119    }
120
121    @Override
122    public Set<Object> getSingletons() {
123        return get().getSingletons();
124    }
125
126}