java - Arraylist 检查 CustomerID 是否在 Rent ArrayList 中

Question

我目前有 2 个 Arraylist，其中包含 Customer 和 Bike 构造函数数据。我成功地输入并租用 Arraylist 使用:

rent.add(new Rent(customers.get(1),bike.get(1)));

如何检查 CustomerID 是否已在 Arraylist 租赁中，并且会给出错误，提示客户已在租赁？

public Rent(Customer customer, Bike bike) {

    this.customers = customer;
    this.bike = bike;
}

public Customer(int CustID, String CustFName, String CustLName) {

    this.CustID = CustID;
    this.CustFName = CustFName;
    this.CustLName = CustLName;
}

public Bike(int BikeID, String BikeType, int PricePerDay,booleanisAvailable) {

    this.BikeID = BikeID;
    this.BikeType = BikeType;
    this.PricePerDay = PricePerDay;
    this.isAvailable = isAvailable;
}

protected ArrayList<Customer> customers = new ArrayList<Customer();
protected ArrayList<Bike> bike = new ArrayList<Bike>();
protected ArrayList<Rent> rent = new ArrayList<Rent>();

Answer 1

假设您正在寻找具有给定 custId 的客户，您可以执行以下操作:

public boolean isAlreadyRenting(Customer cust) {
    return rent.stream().anyMatch(r -> r.getCustomer().getCustId() == cust.getCustId());
}