TreeSet自定义类

class Student implements Comparable//该接口强制让学生具备比较性
{
    private String name;
    private int age;
    student(String name,int age)
    {
        this.name = name;
        this.age = age;
    }

    public int compareTo(Object obj)//覆盖接口里的compareTo方法,用Object 接收参数,不能声明异常
    {
    if(!(obj instanceof Student))//先判断obj是Student类的实例
        throw new RuntimeException("不是学生对象")//抛出运行时异常
    Student s = (Student)obj;//强转s

    //System.out.println(this.name+"...compareto"+s.name)
    if (this.age>s.age)//调用者比较传入参数,
        return 1;
    if (this.age==s.age)//如果年龄属性相同,再调用名字属性比较
    {
        return this.name.compareTo(s.name);//调用者 调用String类的comparTo方法 按字典顺序比较 (传入参数)
    }       
    if (this.age<s.age)
        return -1;  
    }
    public String getName()
    {
        return name;
    }
    public String getAge()
    {
        return Age;
    }   
}

class  TreeSetDemo2
{
    public static void main(String[] args) 
    {
        TreeSet ts = new TressSet(new MyCompare());//传进比较器
        ts.add(new Student("lisi02",22));
        ts.add(new Student("lisi007",20));
        ts.add(new Student("lisi09",19));
        ts.add(new Student("lisi01",40));

        Iterator it = ts.iterator();
        while(it.hasNext())
        {
            System.out.println(it.next());
        }
    }
}

class MyCompare implements Comparator//定义比较器
{
    public int compare(Object o1,Object o2)
    {
        Student s1 = (Student)o1;
        Student s2 = (Student)o2;
        int num = s1.get.getName().compareTo(s2.getName());
        if(num == 0)
        {
            new Integer(s1.getAge()).compareTo(new Integer(s2.getAge()));
            /*
            if(s1.getAge()>s2.getAge())
                return 1;
            if(s1.getAge()==s2.getAge())
                return 0;
            if(s1.getAge()<s2.getAge())
                return -1;
            */
        }
        return num;
    }
}

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转载自blog.csdn.net/skylibiao/article/details/81323748