用java设计一个简单的学生成绩系统，具有以下功能：添加一个学生；查找一个学生；根据编号更新学生的基本信息（基本信息为姓名与学号）；根据编号删除学生；根据编号输入学生的各门成绩（语文、数学、外语，成绩为int类型）；退出系统。要求过案例驱动法和实验法，

案例驱动法：

1. 首先我们需要定义一个学生类，包含姓名、学号、语文成绩、数学成绩、外语成绩等属性和相应的get/set方法。

public class Student {
    private String name;
    private String id;
    private int chineseScore;
    private int mathScore;
    private int englishScore;

    public Student(String name, String id) {
        this.name = name;
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public int getChineseScore() {
        return chineseScore;
    }

    public void setChineseScore(int chineseScore) {
        this.chineseScore = chineseScore;
    }

    public int getMathScore() {
        return mathScore;
    }

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

    public int getEnglishScore() {
        return englishScore;
    }

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

2. 接下来，我们需要设计一个学生成绩系统类，包含添加学生、查找学生、更新学生信息、删除学生、输入学生成绩等方法。

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class StudentScoreSystem {
    private List<Student> studentList;
    private Scanner scanner;

    public StudentScoreSystem() {
        studentList = new ArrayList<>();
        scanner = new Scanner(System.in);
    }

    public void addStudent() {
        System.out.print("请输入学生姓名：");
        String name = scanner.nextLine();
        System.out.print("请输入学生学号：");
        String id = scanner.nextLine();
        Student student = new Student(name, id);
        studentList.add(student);
        System.out.println("添加成功！");
    }

    public void findStudent() {
        System.out.print("请输入要查找的学生学号：");
        String id = scanner.nextLine();
        for (Student student : studentList) {
            if (student.getId().equals(id)) {
                System.out.println("学生姓名：" + student.getName());
                System.out.println("语文成绩：" + student.getChineseScore());
                System.out.println("数学成绩：" + student.getMathScore());
                System.out.println("外语成绩：" + student.getEnglishScore());
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void updateStudent() {
        System.out.print("请输入要更新的学生学号：");
        String id = scanner.nextLine();
        for (Student student : studentList) {
            if (student.getId().equals(id)) {
                System.out.print("请输入学生姓名：");
                String name = scanner.nextLine();
                student.setName(name);
                System.out.println("更新成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void deleteStudent() {
        System.out.print("请输入要删除的学生学号：");
        String id = scanner.nextLine();
        for (int i = 0; i < studentList.size(); i++) {
            if (studentList.get(i).getId().equals(id)) {
                studentList.remove(i);
                System.out.println("删除成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void inputScore() {
        System.out.print("请输入要输入成绩的学生学号：");
        String id = scanner.nextLine();
        for (Student student : studentList) {
            if (student.getId().equals(id)) {
                System.out.print("请输入语文成绩：");
                int chineseScore = scanner.nextInt();
                student.setChineseScore(chineseScore);
                System.out.print("请输入数学成绩：");
                int mathScore = scanner.nextInt();
                student.setMathScore(mathScore);
                System.out.print("请输入外语成绩：");
                int englishScore = scanner.nextInt();
                student.setEnglishScore(englishScore);
                scanner.nextLine();
                System.out.println("输入成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void exit() {
        System.out.println("退出系统！");
        scanner.close();
        System.exit(0);
    }
}

3. 最后，我们需要在main函数中实现用户菜单，让用户可以选择相应的操作。

public class Main {
    public static void main(String[] args) {
        StudentScoreSystem system = new StudentScoreSystem();
        while (true) {
            System.out.println("请选择操作：");
            System.out.println("1. 添加学生");
            System.out.println("2. 查找学生");
            System.out.println("3. 更新学生信息");
            System.out.println("4. 删除学生");
            System.out.println("5. 输入学生成绩");
            System.out.println("6. 退出系统");
            System.out.print("请选择操作（输入数字）：");
            int choice = system.scanner.nextInt();
            system.scanner.nextLine();
            switch (choice) {
                case 1:
                    system.addStudent();
                    break;
                case 2:
                    system.findStudent();
                    break;
                case 3:
                    system.updateStudent();
                    break;
                case 4:
                    system.deleteStudent();
                    break;
                case 5:
                    system.inputScore();
                    break;
                case 6:
                    system.exit();
                    break;
                default:
                    System.out.println("输入有误，请重新输入！");
                    break;
            }
        }
    }
}

实验法：

1. 根据需求，我们需要设计一个学生类，包含姓名、学号、语文成绩、数学成绩、外语成绩等属性和相应的get/set方法。

public class Student {
    private String name;
    private String id;
    private int chineseScore;
    private int mathScore;
    private int englishScore;

    public Student(String name, String id) {
        this.name = name;
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public int getChineseScore() {
        return chineseScore;
    }

    public void setChineseScore(int chineseScore) {
        this.chineseScore = chineseScore;
    }

    public int getMathScore() {
        return mathScore;
    }

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

    public int getEnglishScore() {
        return englishScore;
    }

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

2. 接下来，我们需要设计一个学生成绩系统类，包含添加学生、查找学生、更新学生信息、删除学生、输入学生成绩等方法。

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class StudentScoreSystem {
    private List<Student> studentList;
    private Scanner scanner;

    public StudentScoreSystem() {
        studentList = new ArrayList<>();
        scanner = new Scanner(System.in);
    }

    public void addStudent() {
        System.out.print("请输入学生姓名：");
        String name = scanner.nextLine();
        System.out.print("请输入学生学号：");
        String id = scanner.nextLine();
        Student student = new Student(name, id);
        studentList.add(student);
        System.out.println("添加成功！");
    }

    public void findStudent() {
        System.out.print("请输入要查找的学生学号：");
        String id = scanner.nextLine();
        for (Student student : studentList) {
            if (student.getId().equals(id)) {
                System.out.println("学生姓名：" + student.getName());
                System.out.println("语文成绩：" + student.getChineseScore());
                System.out.println("数学成绩：" + student.getMathScore());
                System.out.println("外语成绩：" + student.getEnglishScore());
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void updateStudent() {
        System.out.print("请输入要更新的学生学号：");
        String id = scanner.nextLine();
        for (Student student : studentList) {
            if (student.getId().equals(id)) {
                System.out.print("请输入学生姓名：");
                String name = scanner.nextLine();
                student.setName(name);
                System.out.println("更新成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void deleteStudent() {
        System.out.print("请输入要删除的学生学号：");
        String id = scanner.nextLine();
        for (int i = 0; i < studentList.size(); i++) {
            if (studentList.get(i).getId().equals(id)) {
                studentList.remove(i);
                System.out.println("删除成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void inputScore() {
        System.out.print("请输入要输入成绩的学生学号：");
        String id = scanner.nextLine();
        for (Student student : studentList) {
            if (student.getId().equals(id)) {
                System.out.print("请输入语文成绩：");
                int chineseScore = scanner.nextInt();
                student.setChineseScore(chineseScore);
                System.out.print("请输入数学成绩：");
                int mathScore = scanner.nextInt();
                student.setMathScore(mathScore);
                System.out.print("请输入外语成绩：");
                int englishScore = scanner.nextInt();
                student.setEnglishScore(englishScore);
                scanner.nextLine();
                System.out.println("输入成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    public void exit() {
        System.out.println("退出系统！");
        scanner.close();
        System.exit(0);
    }
}

3. 我们可以使用JUnit测试框架来对学生成绩系统进行单元测试，确保其功能正确性。首先，我们需要引入JUnit依赖。

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13.1</version>
    <scope>test</scope>
</dependency>

4. 接下来，我们编写单元测试类，对学生成绩系统的各个方法进行测试。

import org.junit.Before;
import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class StudentScoreSystemTest {
    private StudentScoreSystem system;

    @Before
    public void setUp() {
        system = new StudentScoreSystem();
    }

    @Test
    public void testAddStudent() {
        system.addStudent();
        assertEquals(1, system.getStudentList().size());
    }

    @Test
    public void testFindStudent() {
        system.addStudent();
        system.findStudent();
    }

    @Test
    public void testUpdateStudent() {
        system.addStudent();
        system.updateStudent();
    }

    @Test
    public void testDeleteStudent() {
        system.addStudent();
        system.deleteStudent();
        assertEquals(0, system.getStudentList().size());
    }

    @Test
    public void testInputScore() {
        system.addStudent();
        system.inputScore();
    }
}