001/**
002 *
003 * Copyright the original author or authors
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smack.provider;
018
019import java.io.InputStream;
020import java.util.ArrayList;
021import java.util.Collection;
022import java.util.Collections;
023import java.util.LinkedList;
024import java.util.List;
025import java.util.logging.Level;
026import java.util.logging.Logger;
027
028import org.jivesoftware.smack.packet.IQ;
029import org.jivesoftware.smack.packet.PacketExtension;
030import org.xmlpull.v1.XmlPullParserFactory;
031import org.xmlpull.v1.XmlPullParser;
032
033/**
034 * Loads the {@link IQProvider} and {@link PacketExtensionProvider} information from a standard provider file in preparation 
035 * for loading into the {@link ProviderManager}.
036 * 
037 * @author Robin Collier
038 *
039 */
040public class ProviderFileLoader implements ProviderLoader {
041    private static final Logger LOGGER = Logger.getLogger(ProviderFileLoader.class.getName());
042
043    private Collection<IQProviderInfo> iqProviders;
044    private Collection<ExtensionProviderInfo> extProviders;
045
046    private List<Exception> exceptions = new LinkedList<Exception>();
047
048    public ProviderFileLoader(InputStream providerStream) {
049        this(providerStream, ProviderFileLoader.class.getClassLoader());
050    }
051
052    @SuppressWarnings("unchecked")
053    public ProviderFileLoader(InputStream providerStream, ClassLoader classLoader) {
054        iqProviders = new ArrayList<IQProviderInfo>();
055        extProviders = new ArrayList<ExtensionProviderInfo>();
056        
057        // Load processing providers.
058        try {
059            XmlPullParser parser = XmlPullParserFactory.newInstance().newPullParser();
060            parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, true);
061            parser.setInput(providerStream, "UTF-8");
062            int eventType = parser.getEventType();
063            do {
064                if (eventType == XmlPullParser.START_TAG) {
065                    String typeName = parser.getName();
066                    
067                    try {
068                        if (!"smackProviders".equals(typeName)) {
069                            parser.next();
070                            parser.next();
071                            String elementName = parser.nextText();
072                            parser.next();
073                            parser.next();
074                            String namespace = parser.nextText();
075                            parser.next();
076                            parser.next();
077                            String className = parser.nextText();
078
079                            try {
080                                final Class<?> provider = classLoader.loadClass(className);
081                                // Attempt to load the provider class and then create
082                                // a new instance if it's an IQProvider. Otherwise, if it's
083                                // an IQ class, add the class object itself, then we'll use
084                                // reflection later to create instances of the class.
085                                if ("iqProvider".equals(typeName)) {
086                                    // Add the provider to the map.
087                                    
088                                    if (IQProvider.class.isAssignableFrom(provider)) {
089                                        iqProviders.add(new IQProviderInfo(elementName, namespace, (IQProvider) provider.newInstance()));
090                                    }
091                                    else if (IQ.class.isAssignableFrom(provider)) {
092                                        iqProviders.add(new IQProviderInfo(elementName, namespace, (Class<? extends IQ>)provider));
093                                    }
094                                }
095                                else {
096                                    // Attempt to load the provider class and then create
097                                    // a new instance if it's an ExtensionProvider. Otherwise, if it's
098                                    // a PacketExtension, add the class object itself and
099                                    // then we'll use reflection later to create instances
100                                    // of the class.
101                                    if (PacketExtensionProvider.class.isAssignableFrom(provider)) {
102                                        extProviders.add(new ExtensionProviderInfo(elementName, namespace, (PacketExtensionProvider) provider.newInstance()));
103                                    }
104                                    else if (PacketExtension.class.isAssignableFrom(provider)) {
105                                        extProviders.add(new ExtensionProviderInfo(elementName, namespace, provider));
106                                    }
107                                }
108                            }
109                            catch (ClassNotFoundException cnfe) {
110                                LOGGER.log(Level.SEVERE, "Could not find provider class", cnfe);
111                                exceptions.add(cnfe);
112                            }
113                        }
114                    }
115                    catch (IllegalArgumentException illExc) {
116                        LOGGER.log(Level.SEVERE, "Invalid provider type found [" + typeName + "] when expecting iqProvider or extensionProvider", illExc);
117                        exceptions.add(illExc);
118                    }
119                }
120                eventType = parser.next();
121            }
122            while (eventType != XmlPullParser.END_DOCUMENT);
123        }
124        catch (Exception e){
125            LOGGER.log(Level.SEVERE, "Unknown error occurred while parsing provider file", e);
126            exceptions.add(e);
127        }
128        finally {
129            try {
130                providerStream.close();
131            }
132            catch (Exception e) {
133                // Ignore.
134            }
135        }
136    }
137
138    @Override
139    public Collection<IQProviderInfo> getIQProviderInfo() {
140        return iqProviders;
141    }
142
143    @Override
144    public Collection<ExtensionProviderInfo> getExtensionProviderInfo() {
145        return extProviders;
146    }
147
148    public List<Exception> getLoadingExceptions() {
149        return Collections.unmodifiableList(exceptions);
150    }
151}