Spark研究笔记8：重要的工厂类PluginManager（原创）

private final List<Plugin> plugins = new ArrayList<Plugin>();//Plugin接口

//PublicPlugin是注册的插件，字面含义是公开
private final List<PublicPlugin> publicPlugins = new CopyOnWriteArrayList<PublicPlugin>();
//单例管理器
private static PluginManager singleton;
private static final Object LOCK = new Object();

//Plugins 目录下的文件
public static File PLUGINS_DIRECTORY = new File(Spark.getBinDirectory().getParent(), "plugins").getAbsoluteFile();

private Plugin pluginClass;
private PluginClassLoader classLoader;

//黑名单插件，也就是被禁用的插件
private Collection<String> _blacklistPlugins;

构造函数：

private PluginManager() {
try {
//定义PLUGINS_DIRECTORY
PLUGINS_DIRECTORY = new File(Spark.getBinDirectory().getParentFile(), "plugins").getCanonicalFile();
}
catch (IOException e) {
Log.error(e);
}

// Do not use deployable plugins if not installed.
if (System.getProperty("plugin") == null) {
movePlugins();
}

// Create the extension directory if one does not exist.
if (!PLUGINS_DIRECTORY.exists()) {
PLUGINS_DIRECTORY.mkdirs();
}

_blacklistPlugins = Default.getPluginBlacklist();

//Default.getPluginBlacklist定义了插件黑名单，在default.properties里设置，用于禁用插件，第132行：
# Put plugins here that you dont want enabled
# comma separated, case insensitive
# names of plugins can be found in the plugin.xml
# example: Fastpath,Jingle Client,Phone Client,Window Flashing Plugin
# default is empty
PLUGIN_BLACKLIST =
# Disable Plugins by entrypoint Class
# Comma seperated, case sensitive
# example org.jivesoftware.fastpath.FastpathPlugin
# default is empty
PLUGIN_BLACKLIST_CLASS =
}

　　/**
* 载入所有的插件（通过plugins.xml、lib）
*/
public void loadPlugins() {

　　/**
载入已注册插件*/
private Plugin loadPublicPlugin(File pluginDir) {

/**
* 插件初始化*/
public void initializePlugins() {

/**
* 安装新插件*/
public void addPlugin(PublicPlugin plugin) throws Exception {