defaultapplicationinitializer.java

java插件系统源码

        try {
            blackList = loadList(
                    configuration.getProperty(PARAM_PLUGINS_BLACK_LIST, null));
        } catch (IOException ioe) {
            log.warn("failed loading black list", ioe); //$NON-NLS-1$
        }
        if (blackList != null) {
            log.debug("black list loaded"); //$NON-NLS-1$
        }
    }
    
    private Set loadList(final String location) throws IOException {
        if (location == null) {
            return null;
        }
        Set result = new HashSet();
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                new FileInputStream(location), "UTF-8")); //$NON-NLS-1$
        try {
            String line;
            while ((line = reader.readLine()) != null) {
                line = line.trim();
                if (line.length() > 0) {
                    result.add(line);
                }
            }
        } finally {
            reader.close();
        }
        log.debug("read " + result.size() //$NON-NLS-1$
                + " list items from " + location); //$NON-NLS-1$
        return result;
    }
    
    private PluginsCollector getCollectorInstance(
            final String className) {
        if (className != null) {
            try {
                return (PluginsCollector) Class.forName(className)
                    .newInstance();
            } catch (InstantiationException ie) {
                log.warn("failed instantiating plug-ins collector " //$NON-NLS-1$
                        + className, ie);
            } catch (IllegalAccessException iae) {
                log.warn("failed instantiating plug-ins collector " //$NON-NLS-1$
                        + className, iae);
            } catch (ClassNotFoundException cnfe) {
                log.warn("failed instantiating plug-ins collector " //$NON-NLS-1$
                        + className, cnfe);
            }
        }
        return new DefaultPluginsCollector();
    }
    
    /**
     * Initializes application. The sequence is:
     * <ul>
     *   <li>Collect plug-ins locations using configured
     *     {@link PluginsCollector}.</li>
     *   <li>Get {@link PluginManager} instance from {@link ObjectFactory}
     *     using code
     *     <code>ObjectFactory.newInstance(config).createManager()</code>.</li>
     *   <li>Publish collected plug-ins using
     *     {@link PluginManager#publishPlugins(org.java.plugin.PluginManager.PluginLocation[])}.</li>
     *   <li>Check integrity if that's configured.</li>
     *   <li>Get application plug-in and call it
     *     <code>JpfApplication initApplication(Properties)</code> method.</li>
     *   <li>Return received instance of {@link Application} interface.</li>
     * </ul>
     * 
     * @see org.java.plugin.boot.ApplicationInitializer#initApplication(
     *      BootErrorHandler, String[])
     */
    public Application initApplication(final BootErrorHandler errorHandler,
            final String[] args) throws Exception {
        // Prepare parameters to start plug-in manager.
        log.debug("collecting plug-in locations"); //$NON-NLS-1$
        Collection pluginLocations = collector.collectPluginLocations();
        log.debug("collected " + pluginLocations.size() //$NON-NLS-1$
                + " plug-in locations, instantiating plug-in manager"); //$NON-NLS-1$
        // Create instance of plug-in manager.
        PluginManager pluginManager =
            ObjectFactory.newInstance(config).createManager();
        pluginLocations = filterPluginLocations(pluginManager.getRegistry(),
                pluginLocations);
        log.debug(pluginLocations.size() + " plug-in locations remain after " //$NON-NLS-1$
                + "applying filters, publishing plug-ins"); //$NON-NLS-1$
        // Publish discovered plug-in manifests and corresponding plug-in folders.
        pluginManager.publishPlugins(
                (PluginLocation[]) pluginLocations.toArray(
                        new PluginLocation[pluginLocations.size()]));
        if (!"off".equalsIgnoreCase(integrityCheckMode)) { //$NON-NLS-1$
            // Check plug-in's integrity.
            log.debug("checking plug-ins set integrity"); //$NON-NLS-1$
            IntegrityCheckReport integrityCheckReport =
                pluginManager.getRegistry().checkIntegrity(
                        "light".equalsIgnoreCase(integrityCheckMode) ? null //$NON-NLS-1$
                            : pluginManager.getPathResolver());
            log.info("integrity check done: errors - " //$NON-NLS-1$
                    + integrityCheckReport.countErrors() + ", warnings - " //$NON-NLS-1$
                    + integrityCheckReport.countWarnings());
            if (integrityCheckReport.countErrors() != 0) {
                // Something wrong in plug-ins set.
                log.info(integrityCheckReport2str(integrityCheckReport));
                if (!errorHandler.handleError(ResourceManager.getMessage(
                        Boot.PACKAGE_NAME, "integrityCheckFailed"), //$NON-NLS-1$
                        integrityCheckReport)) {
                    return null;
                }
            } else if (log.isDebugEnabled()
                    && ((integrityCheckReport.countErrors() > 0)
                    || (integrityCheckReport.countWarnings() > 0))) {
                log.debug(integrityCheckReport2str(integrityCheckReport));
            }
        }
        // application plug-in ID
        String appPluginId = config.getProperty(PARAM_APPLICATION_PLUGIN);
        log.info("application plug-in is " + appPluginId); //$NON-NLS-1$
        // get the start-up application plug-in
        Plugin appPlugin = pluginManager.getPlugin(appPluginId);
        log.debug("got application plug-in " + appPlugin //$NON-NLS-1$
                + ", initializing application"); //$NON-NLS-1$
        if (!(appPlugin instanceof ApplicationPlugin)) {
            log.error("application plug-in class " //$NON-NLS-1$
                    + appPlugin.getClass().getName()
                    + " doesn't assignable with " //$NON-NLS-1$
                    + ApplicationPlugin.class.getName());
            throw new ClassCastException(appPlugin.getClass().getName());
        }
        return ((ApplicationPlugin) appPlugin).initApplication(
                config.getSubset(appPluginId + "."), args); //$NON-NLS-1$
    }
    
    protected String integrityCheckReport2str(final IntegrityCheckReport report) {
        StringBuffer buf = new StringBuffer();
        buf.append("integrity check report:\r\n"); //$NON-NLS-1$
        buf.append("-------------- REPORT BEGIN -----------------\r\n"); //$NON-NLS-1$
        for (Iterator it = report.getItems().iterator(); it.hasNext();) {
            IntegrityCheckReport.ReportItem item =
                (IntegrityCheckReport.ReportItem) it.next();
            buf.append("\tseverity=").append(item.getSeverity()) //$NON-NLS-1$
                .append("; code=").append(item.getCode()) //$NON-NLS-1$
                .append("; message=").append(item.getMessage()) //$NON-NLS-1$
                .append("; source=").append(item.getSource()) //$NON-NLS-1$
                .append("\r\n"); //$NON-NLS-1$
        }
        buf.append("-------------- REPORT END -----------------"); //$NON-NLS-1$
        return buf.toString();
    }

    /**
     * This method may remove unwanted plug-in locations from the given list.
     * Standard implementation applies black/white lists logic.
     * @param registry plug-in registry to process manifests
     * @param pluginLocations collected plug-in locations to be filtered
     * @throws ManifestProcessingException 
     */
    protected Collection filterPluginLocations(final PluginRegistry registry,
            final Collection pluginLocations)
            throws ManifestProcessingException {
        if ((whiteList == null) && (blackList == null)) {
            return pluginLocations;
        }
        List result = new LinkedList();
        for (Iterator ir = pluginLocations.iterator(); ir.hasNext();) {
            PluginLocation pluginLocation = (PluginLocation) ir.next();
            ManifestInfo manifestInfo = registry.readManifestInfo(
                    pluginLocation.getManifestLocation());
            if (whiteList != null) {
                if (isPluginInList(registry, manifestInfo, whiteList)) {
                    result.add(pluginLocation);
                    continue;
                }
            }
            if ((blackList != null)
                    && isPluginInList(registry, manifestInfo, blackList)) {
                continue;
            }
            result.add(pluginLocation);
        }
        return result;
    }
    
    private boolean isPluginInList(final PluginRegistry registry,
            final ManifestInfo manifestInfo, final Set list) {
        if (list.contains(manifestInfo.getId())) {
            return true;
        }
        return list.contains(registry.makeUniqueId(manifestInfo.getId(),
                manifestInfo.getVersion()));
    }
}