Java 为什么子类运行超类构造函数?
当我运行这段代码时,我只是想用班次详细信息和员工填充一个列表,我已经在super类中预先制作了一个员工生成器,所以我认为最好不要重复代码。我可以创建并填充shift数组列表,但每次创建shift对象时,它都会显示Java 为什么子类运行超类构造函数?,java,inheritance,arraylist,Java,Inheritance,Arraylist,当我运行这段代码时,我只是想用班次详细信息和员工填充一个列表,我已经在super类中预先制作了一个员工生成器,所以我认为最好不要重复代码。我可以创建并填充shift数组列表,但每次创建shift对象时,它都会显示EmployeeSheet字段 以下是员工工作表课程: import java.util.*; public class EmployeeSheet extends Employee { private ArrayList<Employee> emp
EmployeeSheet
字段
以下是员工工作表
课程:
import java.util.*;
public class EmployeeSheet
extends Employee {
private ArrayList<Employee> empSheet;
private ProductionWorker pworker;
private ShiftSupervisor sworker;
/**
* Constructs a list of randomly selected employees and displays the list.
*/
public EmployeeSheet() {
empSheet = new ArrayList<Employee>();
Random empPicker = new Random();
for (int i = 0; i < 20; i++) {
int id = empPicker.nextInt(20);
if (id < 12) // roll for production worker
{
System.out.println("Adding Production Worker");
empSheet.add(generateProductionWorker());
} else //roll for Shift supervisor
{
System.out.println("Adding Shift supervisor");
empSheet.add(generateShiftSupervisor());
}
}
Iterator iterator = empSheet.iterator();
while (iterator.hasNext()) {
System.out.println("");
System.out.println(iterator.next());
}
}
/**
* Generates a Production Worker
* @return The fields that make up a Production worker
*/
public ProductionWorker generateProductionWorker() {
Random rng = new Random();
int numberOfEmployeeNames = Ename.length;
ProductionWorker tempPworker = new ProductionWorker();
String employeeName = Ename[rng.nextInt(numberOfEmployeeNames)];
tempPworker.setEmployeeName(employeeName);
int numberOfEmployeeNumbers = Empnum.length;
String employeeNumber = Empnum[rng.nextInt(numberOfEmployeeNumbers)];
tempPworker.setEmployeeNumber(employeeNumber);
int yearHired = rng.nextInt(35) + 1980;
tempPworker.setEmployeehireyear(yearHired);
double weeklySalary = rng.nextInt((100) * 100);
tempPworker.setEmployeeweeklyearning(weeklySalary);
int hourlyRate = rng.nextInt(20) + 10;
tempPworker.setHourlyRate(hourlyRate);
pworker = tempPworker;
return tempPworker;
}
/**
* Generates a ShiftSupervisor employee
* @return the Fields that make up a shift supervisor
*/
public ShiftSupervisor generateShiftSupervisor() {
Random ran = new Random();
int numberOfEmployeeNames = Ename.length;
ShiftSupervisor tempSworker = new ShiftSupervisor();
String employeeName = Ename[ran.nextInt(numberOfEmployeeNames)];
tempSworker.setEmployeeName(employeeName);
int numberOfEmployeeNumbers = Empnum.length;
String employeeNumber = Empnum[ran.nextInt(numberOfEmployeeNumbers)];
tempSworker.setEmployeeNumber(employeeNumber);
int yearHired = ran.nextInt(35) + 1900;
tempSworker.setEmployeehireyear(yearHired);
double weeklySalary = ran.nextInt((100) * 100);
tempSworker.setEmployeeweeklyearning(weeklySalary);
int goalsMet = ran.nextInt(100) + 1;
tempSworker.setGoalsCleared(goalsMet);
double yearlySalary = ran.nextInt((40000) + 40000);
tempSworker.setYearlySalary(yearlySalary);
sworker = tempSworker;
return tempSworker;
}
public int checkSize() {
return empSheet.size();
}
}
import java.util.*;
公共类员工表
扩展员工{
私人ArrayList公司;
私人生产工人;
二等兵;
/**
*构建随机选择的员工列表并显示该列表。
*/
公共雇员表(){
empSheet=newarraylist();
随机选取器=新随机();
对于(int i=0;i<20;i++){
int id=empicker.nextInt(20);
if(id<12)//生产工人卷
{
System.out.println(“添加生产工人”);
添加(generateProductionWorker());
}else//轮班主管登记
{
System.out.println(“添加值班主管”);
添加(generateShiftSupervisor());
}
}
迭代器迭代器=empSheet.Iterator();
while(iterator.hasNext()){
System.out.println(“”);
System.out.println(iterator.next());
}
}
/**
*生成生产工人
*@返回组成生产工人的字段
*/
公共生产工人一代生产工人(){
随机rng=新随机();
int numberOfEmployeeNames=Ename.length;
ProductionWorker tempPworker=新ProductionWorker();
字符串employeeName=Ename[rng.nextInt(numberOfEmployeeNames)];
tempWorker.setEmployeeName(employeeName);
int numberOfEmployeeNumbers=Empnum.length;
字符串employeeNumber=Empnum[rng.nextInt(numberOfEmployeeNumbers)];
tempPworker.setEmployeeNumber(employeeNumber);
国际雇佣年=rng.nextInt(35)+1980年;
临时工。setEmployeehireyear(雇佣年);
双周工资=rng.nextInt((100)*100);
tempPworker.SetEmployeeWeekleForwarding(每周一次);
整小时利率=rng.nextInt(20)+10;
临时工设置小时费率(小时费率);
工友=临时工友;
返回临时工;
}
/**
*生成ShiftsPervisor员工
*@返回构成值班主管的字段
*/
公共班长主管发电机提升主管(){
Random ran=新的Random();
int numberOfEmployeeNames=Ename.length;
ShiftsPervisor tempSworker=新的ShiftsPervisor();
字符串employeeName=Ename[ran.nextInt(numberOfEmployeeNames)];
tempSworker.setEmployeeName(employeeName);
int numberOfEmployeeNumbers=Empnum.length;
字符串employeeNumber=Empnum[ran.nextInt(numberOfEmployeeNumbers)];
tempSworker.setEmployeeNumber(employeeNumber);
int yearHired=ran.nextInt(35)+1900;
tempSworker.setEmployeehireyear(雇佣年);
双周日历=ran.nextInt((100)*100);
tempSworker.SetEmployeeWeekleDressing(每周一次);
int goalsMet=ran.nextInt(100)+1;
tempSworker.setGoalsCleared(goalsMet);
双年度平均值=ran.nextInt((40000)+40000);
tempSworker.setYearlySalary(yearlySalary);
斯沃克=坦普斯沃克;
返回坦普斯沃克;
}
公共int checkSize(){
返回empSheet.size();
}
}
这是班次:
import java.util.*;
public class Shift
extends EmployeeSheet {
private ArrayList<Employee> shiftDetails;
private ProductionWorker pWorker;
private ShiftSupervisor sWorker;
public Shift() {
this.generateShift();
}
// instance variables - replace the example below with your own
/**
* Constructor for objects of class Shift
*/
public void generateShift() {
shiftDetails = new ArrayList();
Random supervisorCount = new Random();
int ssID = supervisorCount.nextInt(3);
for (int i = 0; i < ssID; i++) {
shiftDetails.add(this.generateShiftSupervisor());
}
Random productionCount = new Random();
int prodID = productionCount.nextInt(15) + 5;
for (int d = 0; d < prodID; d++) {
shiftDetails.add(this.generateProductionWorker());
}
}
public ProductionWorker generateProductionWorker() {
pWorker = super.generateProductionWorker();
return pWorker;
}
public ShiftSupervisor generateShiftSupervisor() {
sWorker = super.generateShiftSupervisor();
return sWorker;
}
}
import java.util.*;
公共阶级转移
扩展员工表{
私有数组列表移位细节;
私人生产工人;
二等兵;
公共班次(){
这个。generateShift();
}
//实例变量-将下面的示例替换为您自己的
/**
*类Shift对象的构造函数
*/
公共void generateShift(){
shiftDetails=newArrayList();
Random supervisorCount=新随机数();
int ssID=监管者计数下一个(3);
对于(int i=0;i
知道为什么会这样吗
为什么子类运行超类构造函数
来构造基础对象。否则它将是未构造的,继承语义将是不完整的
每次创建shift对象时,它都会显示EmployeeSheet字段
因为EmployeeSheet的构造函数显示这些字段
知道为什么会这样吗
因为轮班延长了员工工作表
为什么子类运行超类构造函数
来构造基础对象。否则它将是未构造的,继承语义将是不完整的
每次创建shift对象时,它都会显示EmployeeSheet字段
因为EmployeeSheet的构造函数显示这些字段
知道为什么会这样吗
因为Shift扩展了EmployeeSheet。用Java编写的任何构造函数都是从调用另一个构造函数开始的。如果没有显式编写,编译器会为您编写以下行作为构造函数的第一行:
super();
那