定义一个Student类，其中含有成员变量stuId学号、name姓名、department系别及score成绩; 若想对Student类的多个对象进行以stuId或者department及score等为依据进行三种不同的排序，如何实现？ 并写出代码来验证。

要对Student类的多个对象进行不同的排序，可以使用Java中的Comparator接口和Comparable接口实现。

首先，定义Student类，实现Comparable接口，用于stuId排序：

public class Student implements Comparable<Student> {
    private String stuId;
    private String name;
    private String department;
    private double score;

    // 构造函数
    public Student(String stuId, String name, String department, double score) {
        this.stuId = stuId;
        this.name = name;
        this.department = department;
        this.score = score;
    }

    // 实现Comparable接口的compareTo方法，用于stuId排序
    @Override
    public int compareTo(Student other) {
        return this.stuId.compareTo(other.stuId);
    }

    // getter和setter方法
    public String getStuId() {
        return stuId;
    }

    public void setStuId(String stuId) {
        this.stuId = stuId;
    }

    public String getName() {
        return name;
    }

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

    public String getDepartment() {
        return department;
    }

    public void setDepartment(String department) {
        this.department = department;
    }

    public double getScore() {
        return score;
    }

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

接着，定义三个Comparator接口实现类，分别用于不同的排序方式：

public class StuIdComparator implements Comparator<Student> {
    @Override
    public int compare(Student s1, Student s2) {
        return s1.getStuId().compareTo(s2.getStuId());
    }
}

public class DepartmentComparator implements Comparator<Student> {
    @Override
    public int compare(Student s1, Student s2) {
        return s1.getDepartment().compareTo(s2.getDepartment());
    }
}

public class ScoreComparator implements Comparator<Student> {
    @Override
    public int compare(Student s1, Student s2) {
        if (s1.getScore() > s2.getScore()) {
            return 1;
        } else if (s1.getScore() < s2.getScore()) {
            return -1;
        } else {
            return 0;
        }
    }
}

最后，使用Collections类的sort方法对Student对象进行排序：

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Test {
    public static void main(String[] args) {
        List<Student> students = new ArrayList<>();
        students.add(new Student("1001", "张三", "计算机科学与技术", 85.5));
        students.add(new Student("1002", "李四", "软件工程", 92.0));
        students.add(new Student("1003", "王五", "信息与通信工程", 80.0));

        // 按stuId排序
        Collections.sort(students);

        // 按department排序
        Collections.sort(students, new DepartmentComparator());

        // 按score排序
        Collections.sort(students, new ScoreComparator());

        // 输出排序结果
        for (Student s : students) {
            System.out.println(s.getStuId() + " " + s.getName() + " " + s.getDepartment() + " " + s.getScore());
        }
    }
}

在测试代码中，我们创建了一个Student列表，包含三个Student对象，分别按照stuId、department和score进行排序，并输出排序结果。