import java.util.ArrayList;import java.util.List;class Phone {    private String brand;    private double price;    public Phone(String brand, double price) {        this.brand = brand;        this.price = price;    }    @Override    public boolean equals(Object obj) {        if(this == obj){            return true;        }        if(obj == null){            return false;        }        if(! (obj instanceof Phone)){            return false;        }        Phone phone = (Phone) obj;        return this.brand.equals(phone.brand) && this.price==phone.price;    }    @Override    public String toString() {        return brand + price;    }}public class Hello{    public static void main(String args[]) throws Exception{        List<Phone> list = new ArrayList<Phone>();        list.add(new Phone("红米",399));        list.add(new Phone("黑米",499));        System.out.println(list.get(1));            }}