Java 中的循环队列

Question

我正在 java 中实现一个循环队列，它将接受对象 (Employee) 作为条目。现在我有一个方法来编辑特定对象的姓氏，但不知何故我无法从 CQueue [=29] 访问 Employee class 中找到的姓氏 setter 方法=] 即使我正在导入所有必需的包。这是代码：

//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 class:

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 class:

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` Class

package linearnodes;
import dataobjects.*;

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

Answer 1

为了包含工资 "etemp.setPay(newPay);"，您需要将 return 对象更改为员工。

public Employee editObject(String key){

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

因为 AnyClass 还没有"public double pay;"

Answer 2

您的 editobject 方法可能是这样的：

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;
}

您的代码创建了一个新的本地 Employee 实例，该实例在方法结束时终止，其值将丢失，因为没有对象指向它。

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