Java中的循環隊列

Question

我在Java中實現了一個循環隊列，該隊列將接受對象（雇員）作為條目。 現在，我有了一種編輯特定對象的姓氏的方法，但是即使導入所有必需的包，我也無法以某種方式從CQueue類訪問Employee類中的姓氏設置方法。 這是代碼：

//PACKAGES IMPORTED
package linearstructures;
import dataobjects.*;
import linearnodes.*;

public class CQueue{
    Node front, rear, temp;
    boolean full = false;
    String key;

public AnyClass searchKey(String key)
{
    temp = rear.next; // first node

    do
    {
        if (temp.obj.getKey().equals(key))
            return temp.obj;
        temp = temp.next;
    } while (temp != rear.next);

    return null;
}

public AnyClass editObject(String key){
    int choice, newSeqNo;
    double newPay;
    boolean exit = false;
    Employee etemp = new Employee(); //INCLUDED THIS AFTER EDIT
    searchKey(key);

    if(searchKey(key) != null){
        temp.obj.getData();
        System.out.println();
        System.out.println("------------------------");
        System.out.print("Enter new Salary: ");
        newPay = sc.nextDouble();
        System.out.println("------------------------");
        System.out.println();
        etemp.setPay(newPay); //INCLUDED THIS AFTER EDIT
    else
        System.out.println("NO OBJECT WAS FOUND!");
    return null;
}
}

Employee類別：

package dataobjects;

public class Employee extends AnyClass
{
public String surname;
public double pay;

public Employee(){}

public Employee(int seqNo, String surname, double pay)
{
    super(seqNo);
    this.surname = surname;
    this.pay = pay;
}

public double getSalary()
{
    return pay;
}

public void setPay(double newPay)
{
    pay = newPay;
}

public String getData()
{
    return super.getData() + ", Surname: " + surname + ", Pay: " + pay;
}

public String getKey()
{
    return surname;
}
}

AnyClass類：

package dataobjects;

public class AnyClass
{
public int seqNo;

public AnyClass(){}

public AnyClass(int seqNo)
{
    this.seqNo = seqNo;
}

public int getseqNo()
{
    return seqNo;
}

public void setseqNo(int seqNo) {
    this.seqNo = seqNo;
}

public String getData()
{

    return "Sequential Number - " + seqNo;
}

public String getKey()
{
    return Integer.toString(seqNo);     
}

public void edit(){}
}

Node類別

package linearnodes;
import dataobjects.*;

public class Node{
    public AnyClass obj;
    public Node next;
    public Node(AnyClass obj){
        next = null;
        this.obj = obj;
    }
}

Answer 1

for include pay“ etemp.setPay（newPay）;” 您將把返回對象更改為Employee。

public Employee editObject(String key){

Employee etemp = new Employee(); //INCLUDED THIS AFTER EDIT
....
....
etemp.setPay(newPay); //INCLUDED THIS AFTER EDIT
return etemp;
}

因為AnyClass還沒有“公共雙重支付”；

Answer 2

您的editobject方法可能是這樣的：

public AnyClass editObject(String key){
    // ...

    // Store your search result to avoid performing searchKey twice
    AnyClass searchResult = searchKey(key);

    if( searchResult != null ){
        // Check if searchResult is an Employee object
        if( searchResult instanceof Employee )
            // Cast AnyClass to Employee
            Employee empl = (Employee) searchResult;

            // Your logic here...

            // Set properties of the Employee object
            empl.setPay(newPay);

            // ...

           return empl;
        }
        // Add 'else if' here, if you need to manage other Object types
        // otherwise you can join previous if conditions 
    }
    else
        System.out.println("NO OBJECT WAS FOUND!");
    return null;
}

您的代碼創建了一個新的本地Employee實例，該實例在方法結束時終止，其值將丟失，因為沒有對象指向它。