自动注册工厂实例

网络监控项目，初始化时需要对多个任务类注册到类工厂，方便工厂反射，但根据classloader规则，无法初始化与入口类无关的类，因此需要遍历类名，强制加载：

public class TaskRunnableFactory {
	
	public static abstract class TaskRunnable {
		protected RunStat runStat = RunStat.WAIT_FOR_RUN;
		protected Task task;
		protected Context context;
		
		protected void setTask(Context cont, Task task)
		{
			context = cont;
			this.task = task;
		}
		
		protected static HashMap<TaskType, String> prefixMap= new HashMap<TaskType, String>();
		
		public RunStat getRunStat() {
			return runStat;
		}
		
		public abstract void run();
		public abstract int result();
		public abstract String report();
	}
	
	static private HashMap<TaskType, Class<?>> runMap;
	
	public TaskRunnableFactory(Context cont)
	{
		try {
			String path = cont.getPackageResourcePath();
			DexFile df = new DexFile(path);
			for (Enumeration<String> iter = df.entries(); iter.hasMoreElements();) {
				String s = iter.nextElement();
				if (s.startsWith("jd.net.check.runnable.") && !s.contains("$")) {
					Class.forName(s);
				}
			}
		} catch (Exception e) {

		}
	}
	
	static public void registType(TaskType type, Class<?> runClass, String cmd){
		registType(type, runClass);
		TaskRunnable.prefixMap.put(type, cmd);
	}
	
	static public void registType(TaskType type, Class<?> runClass){
		if(runMap==null) runMap = new HashMap<TaskType, Class<?>>();
		runMap.put(type, runClass);
	}	

	public TaskRunnable createRunnalbe(Context cont, Task task) {
		try {
			Class<?> runnableClass = runMap.get(task.getType());
			if (runnableClass == null)
				return null;
			TaskRunnable run = (TaskRunnable) runnableClass.newInstance();
			run.setTask(cont, task);
			return run;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}
}

public class CmdRunnable extends TaskRunnable {
	static {
		TaskRunnableFactory.registType(TaskType.CMD, CmdRunnable.class);
		TaskRunnableFactory.registType(TaskType.GET_GETPROP, CmdRunnable.class, "getprop");
		TaskRunnableFactory.registType(TaskType.GET_NETSTAT, CmdRunnable.class, "netstat");
		TaskRunnableFactory.registType(TaskType.GET_ROUTE, CmdRunnable.class, "cat /proc/net/route");
		TaskRunnableFactory.registType(TaskType.RUN_PS, CmdRunnable.class, "ps");
		TaskRunnableFactory.registType(TaskType.RUN_IFCONFIG, CmdRunnable.class, "ifconfig");
		TaskRunnableFactory.registType(TaskType.RUN_PING, CmdRunnable.class, "ping");
	}

	private ExecRes res = new ExecRes();
	
	@Override
	public void run() {
		runStat = RunStat.RUNNING;
		String cmd = String.format("%s %s", prefixMap.get(task.getType()), task.getCmd());
		SysUtils.exec(cmd, res);
		runStat = (res.ret<0)?RunStat.ERROR:RunStat.DONE;
	}

	@Override
	public int result() {
		return res.ret;
	}

	@Override
	public String report() {
		return res.output;
	}
}