第1,2题：创建4个类：Worker、Recruiter、Candidates、WorkTest
Worker类代码：

package com.imooc.test;

public class Worker {
    private String name;
    private String sex;

    public Worker(String name, String sex) {
        this.name = name;
        this.sex = sex;
    }

    public Worker() {
    }

    public String getName() {
        return name;
    }

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

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public void post() {
        System.out.println("岗位");
    }
    public void resume() {
        System.out.println("简历");
    }
    public void interview() {
        System.out.println("面试");
    }
}

Recruiter类代码：

package com.imooc.test;

public class Recruiter extends Worker{
    private String companyName;

    public Recruiter(String name, String sex, String companyName) {
        super(name, sex);
        this.companyName = companyName;
    }

    public Recruiter() {
    }

    public String getCompanyName() {
        return companyName;
    }

    public void setCompanyName(String companyName) {
        this.companyName = companyName;
    }

    @Override
    public void post() {
        System.out.println("我是"+companyName+"的招聘官，我正在发布岗位");
    }
    @Override
    public void resume() {
        System.out.println("我是"+companyName+"的招聘官，我正在筛选简历");
    }
    @Override
    public void interview() {
        System.out.println("招聘者: " + getName() + "\n性别：" + getSex() + "\n公司：" + companyName + "\n已发出面试邀请，等你来哦~");
    }
}

Candidates类代码：

package com.imooc.test;

public class Candidates extends Worker{
    private int age;

    public Candidates(String name, String sex, int age) {
        super(name, sex);
        this.age = age;
    }

    public Candidates() {
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public void post() {
        System.out.println("我是"+getName()+"我正在浏览岗位");
    }

    @Override
    public void resume() {
        System.out.println("我是"+getName()+"我正在投递简历");
    }

    @Override
    public void interview() {
        System.out.println("应聘者: " + getName() + "\n性别：" + getSex() + "\n年龄：" + age + "\n已收到面试邀请，准时赴约!");
    }
}

WorkTest类代码：

package com.imooc.test;

public class WorkTest {
    public static void main(String[] args) {
        Worker recruiter = new Recruiter("大毛","boy","慕课网教育有限公司");
        Worker candidates = new Candidates("小慕","boy",18);
        recruiter.interview();
        System.out.println("----------------------------------------");
        candidates.interview();
    }
}