1、创建main方法并编写如下代码 2、增加班内的3个学生（姓名和年龄随意） 3、增加班内的3个班委（职位随意） 4、显示学生和班委学习和工作的内容

首先，我们需要在Java程序中创建一个`main`方法作为程序的入口点。下面是一个简单的例子，它会按照您的要求创建一个班级结构，包含学生和班委，并展示他们的基本信息。

public class Main {
    public static void main(String[] args) {
        // 创建学生列表
        List<Student> students = new ArrayList<>();
        students.add(new Student("小明", 16));
        students.add(new Student("小红", 15));
        students.add(new Student("小刚", 17));

        // 创建班委列表
        List<ClassCommitteeMember> committeeMembers = new ArrayList<>();
        ClassCommitteeMember monitor = new ClassCommitteeMember("班长", "张三", 18);
        committeeMembers.add(monitor);
        ClassCommitteeMember viceMonitor = new ClassCommitteeMember("副班长", "李四", 17);
        committeeMembers.add(viceMonitor);
        ClassCommitteeMember secretary = new ClassCommitteeMember("学习委员", "王五", 16);
        committeeMembers.add(secretary);

        // 显示学生信息
        for (Student student : students) {
            System.out.printf("%s, %d岁%n", student.getName(), student.getAge());
        }

        // 显示班委信息
        for (ClassCommitteeMember member : committeeMembers) {
            System.out.printf("%s, %s, %d岁%n", member.getTitle(), member.getName(), member.getAge());
        }
    }
}

class Student {
    private String name;
    private int age;

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

    // getters and setters...
    public String getName() { return name; }
    public int getAge() { return age; }
}

class ClassCommitteeMember {
    private String title;
    private String name;
    private int age;

    public ClassCommitteeMember(String title, String name, int age) {
        this.title = title;
        this.name = name;
        this.age = age;
    }

    // getters and setters...
    public String getTitle() { return title; }
    public String getName() { return name; }
    public int getAge() { return age; }
}