for (Map.Entry<String, College> entry : colleges.entrySet()) { College college = entry.getValue(); List<ClassInfo> classList = college.getClasses(); for (ClassInfo classInfo : classList) { if (classInfo.hasStudent(studentId)) { Student student = classInfo.getStudent(studentId); System.out.println(student); return; } } }请帮我写出college，College类，student类，ClassInfo类

好的，以下是可能的代码实现： College类： ```java public class College { private String name; private List<ClassInfo> classes; public College(String name, List<ClassInfo> classes) { this.name = name; this.classes = classes; } public String getName() { return name; } public List<ClassInfo> getClasses() { return classes; } } ``` ClassInfo类： ```java public class ClassInfo { private String name; private List<Student> students; public ClassInfo(String name, List<Student> students) { this.name = name; this.students = students; } public String getName() { return name; } public List<Student> getStudents() { return students; } public boolean hasStudent(String studentId) { for (Student student : students) { if (student.getId().equals(studentId)) { return true; } } return false; } public Student getStudent(String studentId) { for (Student student : students) { if (student.getId().equals(studentId)) { return student; } } return null; } } ``` Student类： ```java public class Student { private String id; private String name; private int age; public Student(String id, String name, int age) { this.id = id; this.name = name; this.age = age; } public String getId() { return id; } public String getName() { return name; } public int getAge() { return age; } @Override public String toString() { return "Student{" + "id='" + id + '\'' + ", name='" + name + '\'' + ", age=" + age + '}'; } } ``` 其中，colleges是一个Map<String, College>类型的变量，存储了所有学校的信息，每个学校对应一个College对象，而每个College对象包含了若干个ClassInfo对象，每个ClassInfo对象包含了若干个Student对象。上述代码中的方法实现了根据给定的学生ID，从所有学校的所有班级中查找该学生的信息，并输出其信息。