java8 Optional使用 stream filter多级过滤

java8 Optional使用 stream filter多级过滤

package com.example.core.mydemo.java8;


public class MyModel {
    private String couponCode;
    private Integer orderType;
    private String orderNo;
    private String frameNo;
    private Integer couponStatus = 0;  //默认

    public Integer getCouponStatus() {
        return couponStatus;
    }

    public void setCouponStatus(Integer couponStatus) {
        this.couponStatus = couponStatus;
    }

    public String getOrderNo() {
        return orderNo;
    }

    public void setOrderNo(String orderNo) {
        this.orderNo = orderNo;
    }

    public String getFrameNo() {
        return frameNo;
    }

    public void setFrameNo(String frameNo) {
        this.frameNo = frameNo;
    }

    public String getCouponCode() {
        return couponCode;
    }

    public void setCouponCode(String couponCode) {
        this.couponCode = couponCode;
    }

    public Integer getOrderType() {
        return orderType;
    }

    public void setOrderType(Integer orderType) {
        this.orderType = orderType;
    }
}


package com.example.core.mydemo.java8;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;

public class ListTest {
    public static void main(String[] args) {

        List<MyModel> list = new ArrayList();
        MyModel model = new MyModel();
        model.setCouponCode("111111");
        model.setCouponStatus(1);
        model.setOrderType(1);
        list.add(model);

        model = new MyModel();
        model.setCouponCode("22222");
        model.setCouponStatus(0);
        model.setOrderType(2);
        list.add(model);

        int orderType = 1;

        Optional<MyModel> optional = Optional.ofNullable(list).orElseGet(ArrayList::new).stream().filter(x -> x.getOrderType() == orderType).filter(x ->x.getCouponStatus() == 0).findFirst();
        MyModel model3 = optional.orElse(null);
        if(model3 != null) {
            String couponId = model3.getCouponCode();
            //关联订单号
            System.out.println("couponId="+couponId);
        }else{
            System.out.println("未找到未使用的记录");
        }
    }
}