(1)声明Student类。 属性包括：学号、姓名、英语成绩、数学成绩、计算机成绩和总成绩。 方法包括：构造方法、getter方法、setter方法、toString方法、equals方法、compare方法(比较两个学生的总成绩，结果分大于、小于、等于)，sum方法(计算总成绩)和testScore的 方法(计算评测成绩)。 各径 注：评测成绩可以取三门课成绩的平均分，另外任何一门课的成绩的改变都需要对总成绩进行重新计算，因此，在每一个setter方法中应调用sum方法计算总成绩。 (2)声明StudentXW(学习委员)类为Student类的子类。 在StudentXW类中增加责任属性，并覆盖testScore方法(计算评测成绩，评测成绩=三门课的平均分+3)。 (3)声明StudentBZ(班长)类为Student类的子类。 在StudentBZ类中增加责任属性，并覆盖testScore方法(计算评测成绩，评测成绩=三门课的平均分+5)。 (4)声明测试类，生成若干个Student类、StudentXW类及StudentBZ类对象，并分别计算它们的评测成绩。编写一个JAVA程序

以下是代码实现：

public class Student implements Comparable<Student> {
    private int id;
    private String name;
    private int englishScore;
    private int mathScore;
    private int computerScore;
    private int totalScore;

    public Student(int id, String name, int englishScore, int mathScore, int computerScore) {
        this.id = id;
        this.name = name;
        this.englishScore = englishScore;
        this.mathScore = mathScore;
        this.computerScore = computerScore;
        this.totalScore = sum();
    }

    public int getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public int getEnglishScore() {
        return englishScore;
    }

    public void setEnglishScore(int englishScore) {
        this.englishScore = englishScore;
        this.totalScore = sum();
    }

    public int getMathScore() {
        return mathScore;
    }

    public void setMathScore(int mathScore) {
        this.mathScore = mathScore;
        this.totalScore = sum();
    }

    public int getComputerScore() {
        return computerScore;
    }

    public void setComputerScore(int computerScore) {
        this.computerScore = computerScore;
        this.totalScore = sum();
    }

    public int getTotalScore() {
        return totalScore;
    }

    private int sum() {
        return englishScore + mathScore + computerScore;
    }

    private double testScore() {
        return sum() / 3.0;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", englishScore=" + englishScore +
                ", mathScore=" + mathScore +
                ", computerScore=" + computerScore +
                ", totalScore=" + totalScore +
                '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Student student = (Student) o;
        return id == student.id;
    }

    @Override
    public int hashCode() {
        return Objects.hash(id);
    }

    @Override
    public int compareTo(Student o) {
        return Integer.compare(o.totalScore, this.totalScore);
    }
}

public class StudentXW extends Student {
    private String responsibility;

    public StudentXW(int id, String name, int englishScore, int mathScore, int computerScore, String responsibility) {
        super(id, name, englishScore, mathScore, computerScore);
        this.responsibility = responsibility;
    }

    @Override
    public double testScore() {
        return super.testScore() + 3.0;
    }
}

public class StudentBZ extends Student {
    private String responsibility;

    public StudentBZ(int id, String name, int englishScore, int mathScore, int computerScore, String responsibility) {
        super(id, name, englishScore, mathScore, computerScore);
        this.responsibility = responsibility;
    }

    @Override
    public double testScore() {
        return super.testScore() + 5.0;
    }
}

public class Test {
    public static void main(String[] args) {
        List<Student> students = new ArrayList<>();
        students.add(new Student(1, "张三", 80, 90, 70));
        students.add(new StudentXW(2, "李四", 85, 95, 75, "学习委员"));
        students.add(new StudentBZ(3, "王五", 90, 100, 80, "班长"));

        for (Student student : students) {
            System.out.println(student.getName() + "的评测成绩为：" + student.testScore());
        }

        Collections.sort(students);

        System.out.println("总成绩排名：");
        for (int i = 0; i < students.size(); i++) {
            System.out.println("第" + (i + 1) + "名：" + students.get(i).getName() + "，总成绩为：" + students.get(i).getTotalScore());
        }
    }
}

在测试类中，我们创建了三个对象，分别为 `Student`、`StudentXW` 和 `StudentBZ`，并分别计算它们的评测成绩。最后，我们对学生进行按总成绩排序，并输出排名。