小编cod*_*key的帖子

我有一个名单cats，我想组cats具有相同的colour和他们组owner。如何在Java 8中做到这一点？

public class Cat{
    private String name;
    private Owner owner;
    private String color;
    public Cat(String name,Owner owner,String color){
        this.name=name;
        this.owner= owner;
        this.color= color;
    }
}

public class Owner{
    private String name;
    public Owner(String name){
        this.name= name;
    } 
}

可以说我有以下数据：

Owner owner1= new Owner("John");  Owner owner2= new Owner("Smith");
Owner owner3= new Owner("Scott"); 
Cat cat1 = new Cat ("Cat1",owner1,"Brown"); 
Cat cat2 = new Cat ("Cat2",owner2,"Black");
Cat cat3 = new Cat ("Cat3",owner1,"Brown");
Cat cat4 …