Java 如何返回与枚举值等效的字符串

我试图在我的程序中实现这个枚举，以便它返回与枚举值等效的字符串。例如，如果dept的值=3，那么它将返回打印的书籍和电子书

这就是我到目前为止所做的，它似乎不起作用，因为当我转到我的ProgramTester类并尝试添加一个新的OrderItem时，当我为构造函数的部门部分输入一个0-5之间的整数时，它表示构造函数是未定义的

有人知道我做错了什么吗

枚举

public enum Department {

ELECTRICAL(0), PHOTOGRAPHIC(1), COMPUTING(2), BOOKS(3), MUSIC(4), FASHION(5);

private int dNum;

private static String dept[] = { "Electrical & Electronics", "Cameras & Photography", "Laptops, Desktops & Consoles",
        "Printed Books & eBooks", "MP3 & CD Music", "Fashion & Accessories" };

private Department(int num) {
    dNum = num;
}

public String toString() {
    return dept[dNum];
}

}

public class OrderItem {
private int itemCode;
private String itemName;
private String itemSupplier;
private double itemCost;
private Department dept;
private static int nextCode = 1;

public OrderItem(String itemName, String itemSupplier, double itemCost, Department dept) {
    setItemName(itemName);
    setItemSupplier(itemSupplier);
    setItemCost(itemCost);
    setDepartment(dept);
}

public void setItemName(String itemName) {
    if (itemName != null) {
        this.itemName = itemName;
    } else {
        if (this.itemName == null)
            // a default value
            this.itemName = "Unknown";
    }
}

public void setItemSupplier(String itemSupplier) {
    if (itemSupplier != null) {
        this.itemSupplier = itemSupplier;
    } else {
        if (this.itemSupplier == null)
            // a default value
            this.itemSupplier = "Unknown";
    }
}

public void setItemCost(double itemCost) {
    this.itemCost = itemCost;
}

public void setDepartment(Department dept) {
    this.dept = dept;
}

public void setDepartment(int dept) {
    if (dept == 0)
        setDepartment(Department.ELECTRICAL);
    else if (dept == 1)
        setDepartment(Department.PHOTOGRAPHIC);
    else if (dept == 2)
        setDepartment(Department.COMPUTING);
    else if (dept == 3)
        setDepartment(Department.BOOKS);
    else if (dept == 4)
        setDepartment(Department.MUSIC);
    else if (dept == 5)
        setDepartment(Department.FASHION);
}

public String getItemName() {
    return this.itemName;
}

public String getItemSupplier() {
    return this.itemSupplier;
}

public double getItemCost() {
    return this.itemCost;
}

public String getDepartment() {
    return dept.toString();
}

public int useNextCode() {
    itemCode = nextCode;
    nextCode++;
    return itemCode;
}

public String getDetails() {
    String result = "Item name: " + getItemName() + "\n Supplier: " + getItemSupplier() + "\n Department: "
            + getDepartment() + "\n Cost: " + getItemCost();
    return result;
}

public String toString() {
    System.out.println("Item Code: " + useNextCode());
    return getDetails();
}

}

节目

public enum Department {

ELECTRICAL(0), PHOTOGRAPHIC(1), COMPUTING(2), BOOKS(3), MUSIC(4), FASHION(5);

private int dNum;

private static String dept[] = { "Electrical & Electronics", "Cameras & Photography", "Laptops, Desktops & Consoles",
        "Printed Books & eBooks", "MP3 & CD Music", "Fashion & Accessories" };

private Department(int num) {
    dNum = num;
}

public String toString() {
    return dept[dNum];
}

}

public class OrderItem {
private int itemCode;
private String itemName;
private String itemSupplier;
private double itemCost;
private Department dept;
private static int nextCode = 1;

public OrderItem(String itemName, String itemSupplier, double itemCost, Department dept) {
    setItemName(itemName);
    setItemSupplier(itemSupplier);
    setItemCost(itemCost);
    setDepartment(dept);
}

public void setItemName(String itemName) {
    if (itemName != null) {
        this.itemName = itemName;
    } else {
        if (this.itemName == null)
            // a default value
            this.itemName = "Unknown";
    }
}

public void setItemSupplier(String itemSupplier) {
    if (itemSupplier != null) {
        this.itemSupplier = itemSupplier;
    } else {
        if (this.itemSupplier == null)
            // a default value
            this.itemSupplier = "Unknown";
    }
}

public void setItemCost(double itemCost) {
    this.itemCost = itemCost;
}

public void setDepartment(Department dept) {
    this.dept = dept;
}

public void setDepartment(int dept) {
    if (dept == 0)
        setDepartment(Department.ELECTRICAL);
    else if (dept == 1)
        setDepartment(Department.PHOTOGRAPHIC);
    else if (dept == 2)
        setDepartment(Department.COMPUTING);
    else if (dept == 3)
        setDepartment(Department.BOOKS);
    else if (dept == 4)
        setDepartment(Department.MUSIC);
    else if (dept == 5)
        setDepartment(Department.FASHION);
}

public String getItemName() {
    return this.itemName;
}

public String getItemSupplier() {
    return this.itemSupplier;
}

public double getItemCost() {
    return this.itemCost;
}

public String getDepartment() {
    return dept.toString();
}

public int useNextCode() {
    itemCode = nextCode;
    nextCode++;
    return itemCode;
}

public String getDetails() {
    String result = "Item name: " + getItemName() + "\n Supplier: " + getItemSupplier() + "\n Department: "
            + getDepartment() + "\n Cost: " + getItemCost();
    return result;
}

public String toString() {
    System.out.println("Item Code: " + useNextCode());
    return getDetails();
}

}

无法在OrderItem构造函数中传递整数（0-5）。相反，您需要传递所需的枚举。这应该行得通

    OrderItem oi =  new OrderItem("PenDrive","HP",300.0, Department.ELECTRICAL);

---

由于标题问题是如何返回

enum

的字符串值，答案可能是重构

enum

以具有

description

字段，而不是字符串的内部静态数组，并添加一种方法，以按顺序值检索

部门

：

公共枚举部门{
电气（“电气与电子”），
摄影（“照相机和摄影”），
计算机（“笔记本电脑、台式机和控制台”），
书籍（“印刷书籍和电子书”），
音乐（“MP3和CD音乐”），
时尚（“时尚与配饰”）；
私有字符串描述；
私人部门（字符串描述）{
this.description=描述；
}
公共字符串toString（）{
返回此.description；
}
公共静态部门拜纳姆（国际顺序）{
if（序数FASHION.ordinal（））{
返回null；//或抛出IllegalArgumentException
}
返回部门。值（）[序号]；
}
}  

然后方法

OrderItem:：setDepartment（int dept）

可以这样更改（而不是多个

if

语句）：

公共部门（内部部门）{
可选。不可用（部门。拜纳姆（部门））
.ifPresent（OrderItem:：setDepartment）；
}    

您应该将这些值链接到枚举本身，而不是链接到您想发布一个简洁说明问题的其他arrayPerhaps。