Activivtyスタック操作

package com.intsun.icbcgift.lh.tool;
import java.util.Stack;
import android.app.Activity;

public class ActiivtyStack {
private static Stack<Activity> activityStack;
private static ActiivtyStack instance;
	private ActiivtyStack(){
		
	}
	public static ActiivtyStack getScreenManager(){
		if(instance==null){
		instance=new ActiivtyStack();
		}
		return instance;
	}


	public void popActivity(){
			Activity activity=activityStack.lastElement();
			if(activity!=null){
				activity.finish();
				activity=null;
			}
	}
	public void popActivity(Activity activity){
		if(activity!=null){
			activity.finish();
			activityStack.remove(activity);
			activity=null;
		}
	}
	
	public Activity currentActivity(){
		Activity activity=activityStack.lastElement();
		return activity;
	}
	
	
	public void pushActivity(Activity activity){
		if(activityStack==null){
		    activityStack=new Stack<Activity>();
		}
		activityStack.add(activity);
	}
	
	//  Activity
	public void popAllActivityExceptOne(Class<?> cls) {
		while (true) {
			Activity activity = currentActivity();
			if (activity == null) {
				break;
			}
			if (activity.getClass().equals(cls)) {
				break;
			}
			popActivity(activity);
		}
	}
}

 
 activity 
 // 
    	 ActiivtyStack actiivtyStack=ActiivtyStack.getScreenManager();
    	actiivtyStack.pushActivity(AddConsigneActivity.this);
    	// 
     	findViewById(R.id.back).setOnClickListener(new View.OnClickListener() {

 			public void onClick(View arg0) {
 				ActiivtyStack actiivtyStack=ActiivtyStack.getScreenManager();
				actiivtyStack.popAllActivityExceptOne(MyAddrss.class);
 			}
 		});