java ①学校有2种员工：助教（Assistant）、收银员（Cashier）。助教的行为action()是：协助老师修改作业；收银员的行为action()是:在餐馆打工收银。②员工可以通过学校S

以下是Java代码和类图：

```java
//员工类
public abstract class Employee {
public abstract void action();
}

//助教类
public class Assistant extends Employee {
@Override
public void action() {
System.out.println("正在协助老师批作业...");
}
}

//收银员类
public class Cashier extends Employee {
@Override
public void action() {
System.out.println("正在餐馆打工收银...");
}
}

//学校类
public class School {
public void enter(Employee employee) {
employee.action();
}

public void run() {
Employee xiaoming = new Cashier();
Employee xiaodong = new Assistant();
enter(xiaoming);
enter(xiaodong);
}
}

//测试类
public class Test {
public static void main(String[] args) {
School school = new School();
school.run();
}
}
```

类图如下：