java - 如何将创建的对象存储到 ArrayList 中并返回它？

Question

我被要求创建一个名为 listOfWorkers 的方法，在该方法中，我将通过读取文件“workers.txt”中的数据来创建我拥有的 3 个 worker 的每种类型的对象，然后将对象存储到类型的 ArrayList 中 worker 并将其归还。我已经通过从文件中读取数据成功地制作了 3 个 worker 的每种类型的对象，但现在我不知道如何将它们存储到 ArrayList 中。大家有什么帮助吗？

我现在正在编码的类(class)

import java.util.*;
import java.io.*;

public class WorkerBenefits 
{
public ArrayList<Worker> listOfWorkers()
{



    try
    {

        File ifile = new File("worker.txt");
        Scanner scan = new Scanner(ifile);
        while (scan.hasNextLine())
        {
            String line = scan.nextLine();
            StringTokenizer st = new StringTokenizer(line,",");
            String jobs = st.nextToken();
            Jobs jobType = Jobs.valueOf(jobs);
            //Engineer Object type 
            if (jobType == Jobs.ELECTRICAL_ENGINEER || jobType == Jobs.MECHANICAL_ENGINEER)
            {
                String name = st.nextToken();
                String str1 = st.nextToken();
                int social = Integer.parseInt(str1);
                String str2 = st.nextToken();
                int years = Integer.parseInt(str2);
                String str3 = st.nextToken();
                double weeklyBen = Double.parseDouble(str3);
                Engineer eng = new Engineer(name,social,years,jobType,weeklyBen);
            }
            //Admin. Person. Object  type
            else if (jobType == Jobs.ADMINISTRATIVE_SECRETARY || jobType == Jobs.ADMINISTRATIVE_ASSISTANT)
            {
                String name = st.nextToken();
                String str1 = st.nextToken();
                int social = Integer.parseInt(str1);
                String str2 = st.nextToken();
                int years = Integer.parseInt(str2);
                String str3 = st.nextToken();
                double rate = Double.parseDouble(str3);
                String str4 = st.nextToken();
                double hours = Double.parseDouble(str4);
                AdministrativePersonnel ap = new AdministrativePersonnel(name,social,years,jobType,rate,hours);
            }
            //Management Object type
            else if (jobType == Jobs.ENGINEERING_MANAGER || jobType == Jobs.ADMINISTRATIVE_MANAGER)
            {
                String name = st.nextToken();
                String str1 = st.nextToken();
                int social = Integer.parseInt(str1);
                String str2 = st.nextToken();
                int years = Integer.parseInt(str2);
                String str3 = st.nextToken();
                double weeklyBen = Double.parseDouble(str3);
                String str4 = st.nextToken();
                double bonus = Double.parseDouble(str4);
                Management mang = new Management(name,social,years,jobType,weeklyBen,bonus);
            }
        }
    }
    catch (IOException ioe)
    {
        System.out.println("Something went wrong");
    }
    return ArrayList;
}

}

这是其他类的代码，以防万一你们需要它们:

工作

public enum Jobs {ELECTRICAL_ENGINEER, MECHANICAL_ENGINEER, ADMINISTRATIVE_SECRETARY, ADMINISTRATIVE_ASSISTANT, ENGINEERING_MANAGER, ADMINISTRATIVE_MANAGER, NONE};

worker

public abstract class Worker
{
public String name;
public int socialSecurity;
private int yearsExperience;
public Jobs et = null;
public static int id = 0;
public int currentID = 0;

public Worker ()
{
    name = "AnyName";
    socialSecurity = 12345;
    yearsExperience = 0;
    et = Jobs.NONE;
    id++;
    currentID = id;
}

public Worker (String n, int ss, int ye, Jobs j)
{
    id++;
    currentID = id;
    name = n;
    socialSecurity = ss;
    yearsExperience = ye;
    et = j;
}

public String getName()
{
    return name;
}

public int getSocialSecurity()
{
    return socialSecurity;
}

public int getYearsExperience()
{
    return yearsExperience;
}

public Jobs getJobs()
{
    return et;
}

public void setName(String n1)
{
    name = n1;
}

public void setSocialSecurity(int ss1)
{
    socialSecurity = ss1;
}

public void setYearsExperience(int ye1)
{
    yearsExperience = ye1;
}

public void setJobs(Jobs et1)
{
    et = et1;
}

public abstract double benefitsCalculation(Jobs et2);

public String toString()
{
    String output = "The name is: " + name + "The Job type is: " + et + "The id    is: " + currentID;
    return output;
}
}

工程师

public class Engineer extends Worker
{
private double weeklyBenefits;

public Engineer ()
{
    super();
    weeklyBenefits = 400.00;
}

public Engineer (String n, int ss, int ye, Jobs j, double wb)
{
    super(n,ss,ye,j);
    weeklyBenefits = wb;
    super.setName(n);
    super.setSocialSecurity(ss);
    super.setYearsExperience(ye);
    super.setJobs(j);

}


public double benefitsCalculation(Jobs et2)
{
    double benefits = 0.0;
    if (et2 == Jobs.ELECTRICAL_ENGINEER)
    {
        benefits = weeklyBenefits+super.getYearsExperience()*120.00;
    }
    else if (et2 == Jobs.MECHANICAL_ENGINEER)
    {
        benefits = weeklyBenefits/2+super.getYearsExperience()*120.00;
    }
    else if (et2 != Jobs.ELECTRICAL_ENGINEER || et2 != Jobs.MECHANICAL_ENGINEER)
    {
        benefits = 0;
    }
    return benefits;
}

public double getWeeklyBenefits()
{
    return weeklyBenefits;
}

public void setWeeklyBenefits(double wb)
{
    weeklyBenefits = wb;
}

public String toString()
{
    String output = "The benefit is " + weeklyBenefits + super.toString();
    return output;
}
}

行政人员

public class AdministrativePersonnel extends Worker
{
private double rate;
private double hours;

    public AdministrativePersonnel()
    {
        super();
        rate = 10.0;
        hours = 10.0;
    }

    public AdministrativePersonnel(String n, int ss, int ye, Jobs j, double r, double h)
    {
        super(n,ss,ye,j);
        rate = r;
        hours = h;
        super.setName(n);
        super.setSocialSecurity(ss);
        super.setYearsExperience(ye);
        super.setJobs(j);
    }

    public double benefitsCalculation (Jobs et2)
    {
        double benefits = 0.0;
        if (et2 == Jobs.ADMINISTRATIVE_SECRETARY)
        {
            benefits = rate*hours+super.getYearsExperience()*15.00; 
        }
        else if(et2 == Jobs.ADMINISTRATIVE_ASSISTANT)
        {
            benefits = rate*hours+super.getYearsExperience()*25.00;
        }
        else if (et2 != Jobs.ADMINISTRATIVE_SECRETARY || et2 != Jobs.ADMINISTRATIVE_ASSISTANT)
        {
            benefits = 0;
        }
        return benefits;
    }

    public double getRate()
    {
        return rate;
    }

    public double getHours()
    {
        return hours;
    }

    public void setRate(double r1)
    {
        rate = r1;
    }

    public void setHours(double h1)
    {
        hours = h1;
    }

    public String toString()
    {
        String output = "The rate is: " + rate + "The hours are: " + hours +  super.toString();
        return output;
    }
}

管理

public class Management extends Worker
{
private double weeklyBenefits;
private double bonus;

public Management()
{
    super();
    weeklyBenefits = 0.0;
    bonus = 0.0;
}

public Management(String n, int ss, int ye, Jobs j, double wb, double b)
{
    super(n,ss,ye,j);
    weeklyBenefits = wb;
    bonus = b;
    super.setName(n);
    super.setSocialSecurity(ss);
    super.setYearsExperience(ye);
    super.setJobs(j);
}

public double benefitsCalculation (Jobs et2)
{
        double benefits = 0.0;
        if (et2 == Jobs.ENGINEERING_MANAGER)
        {
            benefits = weeklyBenefits+bonus;    
        }
        else if(et2 == Jobs.ADMINISTRATIVE_MANAGER)
        {
            benefits = weeklyBenefits+0.5*bonus;
        }
        else if (et2 != Jobs.ENGINEERING_MANAGER || et2 != Jobs.ADMINISTRATIVE_MANAGER)
        {
            benefits = 0;
        }
        return benefits;
}

public double getWeeklyBenefits()
{
    return weeklyBenefits;
}

public double getBonus()
{
    return bonus;
}

public void setWeeklyBenefits(double wb)
{
    weeklyBenefits = wb;
}

public void setBonus(double b)
{
    bonus = b;
}

public String toString()
{
    String output = "The weekly benefits are: " + weeklyBenefits + "The bonus is: " + bonus + super.toString();
    return output;
}
}

Answer 1

public ArrayList<Worker> listOfWorkers()
{


    List<Worker> list=new ArrayList<Worker>();

    try
    {

        File ifile = new File("worker.txt");
        Scanner scan = new Scanner(ifile);
        while (scan.hasNextLine())
        {
             // no change
            if (jobType == Jobs.ELECTRICAL_ENGINEER || jobType == Jobs.MECHANICAL_ENGINEER)
            {
               // no change
                Worker eng = new Engineer(name,social,years,jobType,weeklyBen);
                list.add(eng);
            }
            else if()
            {
              //do same as above for other workers
            }
        }
        return list;
}