TreeSet去掉重复对象

Posted 2020-10-19 weishao-lsv

java对象除了采用equals和hashCode判断对象是否相等外，开发人员也可以通过其他属性判断两个对象是否相等

 

以下案例采用TreeSet去掉重复对象

 

Teacher：

public class Teacher{
    private String name;
    private Integer age;
    public Teacher(String name, Integer age) {
        super();
        this.name = name;
        this.age = age;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
}

 

TreeSetTest：

public class TreeSetTest{
    public static void main(String[] args) {
        
        TreeSet<Teacher> set=new TreeSet<Teacher>(new Comparator<Teacher>() {
            @Override
            //通过姓名和年龄判断对象是否相等
            public int compare(Teacher o1, Teacher o2) {
                if(o1.getAge()>o2.getAge()){
                    return 1;
                }else if(o1.getAge()<o2.getAge()){
                    return -1;
                }else{
                    if(o1.getName().compareTo(o2.getName())>0){
                        return 1;
                    }else if(o1.getName().compareTo(o2.getName())==0){
                        return 0;
                    }else{
                        return -1;
                    }
                }
            };
        });
        Teacher p1=new Teacher("小学",20);
        Teacher p2=new Teacher("初中",20);
        Teacher p3=new Teacher("高中",20);
        Teacher p4=new Teacher("初中",20);
        set.add(p1);
        set.add(p2);
        set.add(p3);
        set.add(p4);
        Iterator<Teacher> iterator = set.iterator();
        while(iterator.hasNext()){
            Teacher teacher = iterator.next();
            System.out.print(teacher.getName()+"  ");
        }
    }
    
}

 

结果输出：

　　初中  小学  高中