org.xmpp.component.Component Java Examples

/**
 * Returns the value of an element selected via an xpath expression from
 * a component's component.xml file.
 *
 * @param component the component.
 * @param xpath the xpath expression.
 * @return the value of the element selected by the xpath expression.
 */
private String getElementValue(Component component, String xpath) {
    File componentDir = componentDirs.get(component);
    if (componentDir == null) {
        return null;
    }
    try {
        File componentConfig = new File(componentDir, "component.xml");
        if (componentConfig.exists()) {
            SAXReader saxReader = new SAXReader();
            Document componentXML = saxReader.read(componentConfig);
            Element element = (Element)componentXML.selectSingleNode(xpath);
            if (element != null) {
                return element.getTextTrim();
            }
        }
    }
    catch (Exception e) {
        manager.getLog().error(e);
    }
    return null;
}
 

/**
 * Unloads a component. The {@link ComponentManager#removeComponent(String)} method will be
 * called and then any resources will be released. The name should be the name of the component
 * directory and not the name as given by the component meta-data. This method only removes
 * the component but does not delete the component JAR file. Therefore, if the component JAR
 * still exists after this method is called, the component will be started again the next
 * time the component monitor process runs. This is useful for "restarting" components.<p>
 *
 * This method is called automatically when a component's JAR file is deleted.
 *
 * @param componentName the name of the component to unload.
 */
public void unloadComponent(String componentName) {
    manager.getLog().debug("Unloading component " + componentName);
    Component component = components.get(componentName);
    if (component == null) {
        return;
    }
    File webXML = new File(componentDirectory + File.separator + componentName +
            File.separator + "web" + File.separator + "web.xml");
    if (webXML.exists()) {
        //AdminConsole.removeModel(componentName);
        ComponentServlet.unregisterServlets(webXML);
    }

    ComponentClassLoader classLoader = classloaders.get(component);
    try {
        manager.removeComponent(componentDomains.get(component));
    } catch (ComponentException e) {
        manager.getLog().error("Error shutting down component", e);
    }
    classLoader.destroy();
    components.remove(componentName);
    componentDirs.remove(component);
    classloaders.remove(component);
    componentDomains.remove(component);
}
 

public void addComponent(String subdomain, Component component, Integer port) throws ComponentException {
    if (componentsByDomain.containsKey(subdomain)) {
        if (componentsByDomain.get(subdomain).getComponent() == component) {
            // Do nothing since the component has already been registered
            return;
        }
        else {
            throw new IllegalArgumentException("Subdomain already in use by another component");
        }
    }
    // Create a wrapping ExternalComponent on the component
    ExternalComponent externalComponent = new ExternalComponent(component, this);
    try {
        // Register the new component
        componentsByDomain.put(subdomain, externalComponent);
        components.put(component, externalComponent);
        // Ask the ExternalComponent to connect with the remote server
        externalComponent.connect(host, port, subdomain, startEncrypted);
        // Initialize the component
        JID componentJID = new JID(null, externalComponent.getDomain(), null);
        externalComponent.initialize(componentJID, this);
    }
    catch (ComponentException e) {
        // Unregister the new component
        componentsByDomain.remove(subdomain);
        components.remove(component);
        // Re-throw the exception
        throw e;
    }
    // Ask the external component to start processing incoming packets
    externalComponent.start();
}
 

public ExternalComponent(Component component, ExternalComponentManager manager, int maxThreads) {
    this.component = component;
    this.manager = manager;

    // Create a pool of threads that will process requests received by this component. If more
    // threads are required then the command will be executed on the SocketReadThread process
    threadPool = new ThreadPoolExecutor(maxThreads, maxThreads, 15, TimeUnit.SECONDS,
                    new LinkedBlockingQueue<Runnable>(), new ThreadPoolExecutor.CallerRunsPolicy());
}
 

/**
 * Constructs a new component manager.
 *
 * @param componentDir the component directory.
 */
public ComponentFinder(ServerContainer server, File componentDir) {
    this.componentDirectory = componentDir;
    components = new HashMap<String,Component>();
    componentDirs = new HashMap<Component,File>();
    classloaders = new HashMap<Component,ComponentClassLoader>();
    componentDomains = new HashMap<Component,String>();
    manager = (ExternalComponentManager) server.getManager();
    setupMode = server.isSetupMode();
}
 

/**
 * Returns the name of a component. The value is retrieved from the component.xml file
 * of the component. If the value could not be found, <tt>null</tt> will be returned.
 * Note that this value is distinct from the name of the component directory.
 *
 * @param component the component.
 * @return the component's name.
 */
public String getName(Component component) {
    String name = getElementValue(component, "/component/name");
    if (name != null) {
        return name;
    }
    else {
        return componentDirs.get(component).getName();
    }
}
 

public Component getComponent() {
    return component;
}
 

public void addComponent(String subdomain, Component component) throws ComponentException {
    addComponent(subdomain, component, this.port);
}
 

public ExternalComponent(Component component, ExternalComponentManager manager) {
    // Be default create a pool of 25 threads to process the received requests
    this(component, manager, 25);
}
 

public Class loadClass(String className, Component component) throws ClassNotFoundException,
        IllegalAccessException, InstantiationException
{
    ComponentClassLoader loader = classloaders.get(component);
    return loader.loadClass(className);
}
 

public void query(Component component, IQ packet, IQResultListener listener) throws ComponentException {
    ExternalComponent externalComponent = components.get(component);
    // Add listenet with a timeout of 5 minutes to prevent memory leaks
    externalComponent.addIQResultListener(packet.getID(), listener, 300000);
    sendPacket(component, packet);
}
 

public void sendPacket(Component component, Packet packet) {
    // Get the ExternalComponent that is wrapping the specified component and ask it to
    // send the packet
    components.get(component).send(packet);
}
 

/**
 * Returns the component's directory.
 *
 * @param component the component.
 * @return the component's directory.
 */
public File getComponentDirectory(Component component) {
    return componentDirs.get(component);
}
 

/**
 * Returns the description of a component. The value is retrieved from the component.xml file
 * of the component. If the value could not be found, <tt>null</tt> will be returned.
 *
 * @param component the component.
 * @return the component's description.
 */
public String getDescription(Component component) {
    return getElementValue(component, "/component/description");
}
 

/**
 * Returns the author of a component. The value is retrieved from the component.xml file
 * of the component. If the value could not be found, <tt>null</tt> will be returned.
 *
 * @param component the component.
 * @return the component's author.
 */
public String getAuthor(Component component) {
    return getElementValue(component, "/component/author");
}
 

/**
 * Returns the version of a component. The value is retrieved from the component.xml file
 * of the component. If the value could not be found, <tt>null</tt> will be returned.
 *
 * @param component the component.
 * @return the component's version.
 */
public String getVersion(Component component) {
    return getElementValue(component, "/component/version");
}
 

/**
 * Returns a component by name or <tt>null</tt> if a component with that name does not
 * exist. The name is the name of the directory that the component is in such as
 * "broadcast".
 *
 * @param name the name of the component.
 * @return the component.
 */
public Component getComponent(String name) {
    return components.get(name);
}
 

/**
 * Returns a Collection of all found components.
 *
 * @return a Collection of all found components.
 */
public Collection<Component> getComponents() {
    return Collections.unmodifiableCollection(components.values());
}