方法一 : 

Intent intent = new Intent(this, LoginActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);

方法二 :

public class CacheActivity {

    public static List<Activity> activityList = new LinkedList<Activity>();
    public 
 
CacheActivity() {

    }

    /**
     * 新增到Activity容器中
*/
public static void addActivity(Activity activity) {
        if (!activityList.contains(activity)) {
            activityList.add(activity);
}
    }

    /**
     * 便利所有Activigty並finish
     */
public static void finishActivity() {
        for (Activity activity : activityList
 
) {
            activity.finish();
}
        activityList.clear();
}

    /**
     * 結束指定的Activity
     */
public static void finishSingleActivity(Activity activity) {
        if (activity != null) {
            if (activityList.contains(activity)) {
                activityList.remove(activity);
}
            activity.finish();
 
activity = null;
}
    }

    /**
     * 結束指定類名的Activity 在遍歷一個列表的時候不能執行刪除操作，所有我們先記住要刪除的物件，遍歷之後才去刪除。
*/
public static void finishSingleActivityByClass(Class<?> cls) {
        Activity tempActivity = null;
        for (Activity activity : activityList) {
            if (activity.getClass().equals(cls)) {
                tempActivity = activity;
}
        }

        finishSingleActivity(tempActivity);
}
}

在每次新開啟的Activity的 oncreat() 方法中呼叫 addActivity () 方法, 關閉所有Activity的時候呼叫 finishActivity() 即可.