android spf中存list<string>

private void setSpfList() {
    final SharedPreferences mSharedPreferences = getPreferences(Context.MODE_PRIVATE);

    // Get SharedPreferences editor
    final SharedPreferences.Editor mEditor = mSharedPreferences.edit();
    findViewById(R.id.save).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //储存
            ArrayList<String> list = new ArrayList<String>();
            list.add("1111");
            list.add("2222");
            list.add("3333");
            list.add("4444");
            Set set = new HashSet();
            set.addAll(list);
            mEditor.putStringSet("aaa", set);
            mEditor.commit();
        }
    });
    //得到
    findViewById(R.id.get).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Set<String> set = mSharedPreferences.getStringSet("aaa", null);
            for (String s : set) {
                Log.i("数据",s);
            }
        }
    });
}