一个java List排序实现compare的问题

Question

下面实现的compare是按对象的a属性倒序排序，如何在这个排序中排除掉b属性等于4或5的，
相当于b属性等于4或5的不参与这个倒序排序

List<AA> list = new ArrayList<>();
AA a1 = new AA().setA(1).setB(4);
AA a2 = new AA().setA(0).setB(3);
AA a3 = new AA().setA(0).setB(5);
AA a4 = new AA().setA(0).setB(2);
AA a5 = new AA().setA(1).setB(5);
AA a6 = new AA().setA(1).setB(1);
AA a7 = new AA().setA(0).setB(0);
AA a8 = new AA().setA(1).setB(5);
list.add(a1);list.add(a2);list.add(a3);list.add(a4);list.add(a5);list.add(a6);list.add(a7);list.add(a8);
list.sort((x,y)->{
    if(x.getA() > y.getA()){
        return -1;
    }
    if(x.getA() == y.getA()){
        return 0;
    }
    return 1;

});

Answer 1

package com.xm.officialaccounts.utils;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * @author 
 * @date created in 17:03 2021/6/4
 */
public class a implements Comparable{
    int a;
    int b;
    @Override
    public int compareTo(Object o) {
        a other = (a)o;
        if(b == 4 || b == 5){
            if(other.b == 4 || other.b == 5){
                // 都是a=0级别
                return 0;
            }else {
                return 0 >  other.a ? -1 :1;
            }
        }else {
            if(other.b == 4 || other.b == 5){
                return a > 0 ? -1:1;
            }else {
                return a > other.a ? -1:1;
            }
        }
    }
    public a(int a,int b){
        this.a = a;
        this.b = b;
    }

    public static void main(String[] args) {
        List<a> list = new ArrayList<>();
        a a1 = new a(1,4);
        a a2 = new a(0,3);
        a a3 = new a(0,5);
        a a4 = new a(0,2);
        a a5 = new a(1,5);
        a a6 = new a(1,1);
        a a7 = new a(0,0);
        a a8 = new a(1,5);
        list.add(a1);list.add(a2);list.add(a3);list.add(a4);list.add(a5);list.add(a6);list.add(a7);list.add(a8);
        Collections.sort(list);
        list.stream().forEach(t ->System.out.println(t.a+"========="+t.b));
    }

/*      1=========1
        1=========4
        0=========3
        0=========5
        0=========2
        1=========5
        0=========0
        1=========5*/
}