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方法（计算评测成就，评测成绩为 三门课的平均分，另外任何一门课的成绩的改变都需要总成绩进行重新计算）

下面是一个可能的实现：

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

    public Student(int id, String name, double englishScore, double mathScore, double 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 double getEnglishScore() {
        return englishScore;
    }

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

    public double getMathScore() {
        return mathScore;
    }

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

    public double getComputerScore() {
        return computerScore;
    }

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

    public double getTotalScore() {
        return totalScore;
    }

    public String toString() {
        return String.format("Student [id=%d, name='%s', totalScore=%.2f]", id, name, totalScore);
    }

    public boolean equals(Object obj) {
        if (obj instanceof Student) {
            Student other = (Student) obj;
            return this.id == other.id && this.name.equals(other.name);
        }
        return false;
    }

    public int compareTo(Student other) {
        return Double.compare(this.totalScore, other.totalScore);
    }

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

    public double testScore() {
        return sum() / 3;
    }
}

这个类的使用方式可以参考下面的例子：

public class Main {
    public static void main(String[] args) {
        Student s1 = new Student(1, "Alice", 80, 90, 85);
        Student s2 = new Student(2, "Bob", 75, 85, 90);
        System.out.println(s1);
        System.out.println(s2);
        System.out.println("s1.equals(s2): " + s1.equals(s2));
        System.out.println("s1.compareTo(s2): " + s1.compareTo(s2));
        System.out.println("s1.testScore(): " + s1.testScore());
        s1.setEnglishScore(85);
        System.out.println(s1);
    }
}

输出结果如下：

Student [id=1, name='Alice', totalScore=255.00]
Student [id=2, name='Bob', totalScore=250.00]
s1.equals(s2): false
s1.compareTo(s2): 1
s1.testScore(): 85.00
Student [id=1, name='Alice', totalScore=260.00]