添加重复数据

package com.imooc.test;

public class Student {
	private String name;
	private int stuld;
	private float score;

	public Student() {

	}

	public Student(String name, int stuld, float score) {
		this.setName(name);
		this.setStuld(stuld);
		this.setScore(score);
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getStuld() {
		return stuld;
	}

	public void setStuld(int stuld) {
		this.stuld = stuld;
	}

	public float getScore() {
		return score;
	}

	public void setScore(float score) {
		this.score = score;
	}

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		result = prime * result + stuld;
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj.getClass() == Student.class) {
			Student student = (Student) obj;
			return student.getStuld() == stuld && (student.getName().equals(name));
		}
		return false;

	}

	@Override
	public String toString() {
		return "[学号：" + this.getStuld() + ", 姓名:" + this.getName() + ", 成绩：" + this.getScore() + "]";
	}

}

package com.imooc.test;
问题描述：
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

public class StudentTest {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		Student student3 = new Student("William", 3, 65.0f);
		Student student1 = new Student("Tom", 1, 87.0f);
		Student student2 = new Student("Lucy", 2, 95.0f);
		Set<Student> set = new HashSet<Student>();
		set.add(student1);
		set.add(student2);
		set.add(student3);
		Iterator it = set.iterator();
		while (it.hasNext()) {
			System.out.println(it.next());
		}
		System.out.println("=========================");
		Student student4 = new Student("Lucy", 3, 954.0f);
		Student student5 = new Student("William", 3, 65.0f);
		set.add(student4);
		set.add(student5);
		it = set.iterator();
		while (it.hasNext()) {
			System.out.println(it.next());
		}
	}
}

问题描述：

这个判断是否重复是当学号和姓名都重复时才进行判定重复，单独判断学号或者姓名重复怎么写