Android中 实现队列方式处理优先级信息

Posted 2020-10-26 toolbear

需求：当界面在处理消息A时，突然接收到消息B，需要立马显示B的信息，然后再继续显示消息A，或者接收到消息C，再显示完消息A后再显示消息C；

原理很简单 在一个轮询中，查询消息列表中的元素，先处理优先级最高的那一个，之后再处理优先级次高的那一个；

先做一个对象类

 

    private class Obj{
        int val; 
        int times;
        public Obj(int val, int times){
            this.val = val;
            this.times = times;
        }
    }

再做一个保存消息的列表

List<Obj> mList = new ArrayList<fragment_1.Obj>();

再做一个轮询的机制

private Runnable handlermsg_run = new Runnable() {
        @Override
        public void run() {
            if (mList.size() != 0) {
                Obj val = mList.get(0);
                int tt = doSomething(val);
                state.setText(val.val+" + " + tt);
                if (tt == 0) {
                    mList.remove(0);
                    tv.setText(getList(mList));
                    System.out.println("- remove - " + val.val + ">> " + getList(mList)); 
                }
            } 
            han.postDelayed(this, 500);
        }
    }; 

　　han = new Handler(Looper.getMainLooper());
　　han.post(handlermsg_run);

处理插入列表信息

    private void insert(int random) {
        int times = 5;  
            int newValue = random;
            synchronized (mList) {
                if (mList.size() == 0)
                    mList.add(new Obj(random, times));
                else if (mList.get(0).val != newValue) {
                    boolean sHas = false;
                    for (Obj obj : mList) {
                        if (obj.val == newValue) {
                            sHas = true;
                            break;
                        }
                    }
                    if (!sHas) {
                        mList.add(0, new Obj(newValue, times));
                        sort(mList);
                    }

                }
            }
　　}

对插入的消息进行排序

 

    private static Comparator<? super Obj> comparator = new Comparator<Obj>() {

        @Override
        public int compare(Obj arg0, Obj arg1) {
            return arg0.val - arg1.val;
        }
    };

    private static void sort(List<Obj> mList) {
        Collections.sort(mList, comparator);
    }