如何在java中反转枚举元素的内容

这是我的枚举结构

public enum DictionaryEnum {
        ARROW(
                "Arrow",
                new String[] {
                        "noun"
                },
                new String[] {
                        "Here is one arrow: <IMG> -=>> </IMG>"
                }
        ),
        BOOK(
                "Book",
                new String[]{
                        "noun",
                        "noun",
                        "verb",
                        "verb"
                },
                new String[]{
                        "A set of pages.",
                        "A written work published in printed or electronic form.",
                        "To arrange for someone to have a seat on a plane.",
                        "To arrange something on a particular date."
                }
        );

但正如您所猜测的，它输出整个enum结构的反转，而不是结构内部单个项的反转

public enum DictionaryEnum {
        ARROW(
                "Arrow",
                new String[] {
                        "noun"
                },
                new String[] {
                        "Here is one arrow: <IMG> -=>> </IMG>"
                }
        ),
        BOOK(
                "Book",
                new String[]{
                        "noun",
                        "noun",
                        "verb",
                        "verb"
                },
                new String[]{
                        "A set of pages.",
                        "A written work published in printed or electronic form.",
                        "To arrange for someone to have a seat on a plane.",
                        "To arrange something on a particular date."
                }
        );

例如：如果用户在“book”中键入，则输出应为：

Book [noun] : A set of pages.
Book [noun] : A written work published in printed or electronic form.
Book [verb] : To arrange for someone to have a seat on a plane.
Book [verb] : To arrange something on a particular date.

如果输入“book reverse”，则输出应为

Book [verb] : To arrange something on a particular date.
Book [verb] : To arrange for someone to have a seat on a plane.
Book [noun] : A written work published in printed or electronic form.
Book [noun] : A set of pages.

---

首先需要找到所选的DictionaryEnum：

  DictionaryEnum de = DictionaryEnum.valueOf(keywords[0].toUpperCase());

之后，可以使用给定枚举的数据结构打印出所需内容

---

请注意：我不会对字典之类的东西使用不可修改的数据结构，因为将来很可能需要添加来自其他来源的条目。

您首先需要找到DictionaryEnum selected：

  DictionaryEnum de = DictionaryEnum.valueOf(keywords[0].toUpperCase());

之后，可以使用给定枚举的数据结构打印出所需内容

---

请注意：我不会对字典之类的东西使用不可修改的数据结构，因为将来您很可能希望添加其他来源的条目。

由于您发布了一个不完整的枚举，我必须自己完成缺少的部分。因此请记住，枚举字段名称和方法可能与代码中的名称不同：

public enum DictionaryEnum {
        ARROW(
                "Arrow",
                new String[] {
                        "noun"
                },
                new String[] {
                        "Here is one arrow: <IMG> -=>> </IMG>"
                }
        ),
        BOOK(
                "Book",
                new String[]{
                        "noun",
                        "noun",
                        "verb",
                        "verb"
                },
                new String[]{
                        "A set of pages.",
                        "A written work published in printed or electronic form.",
                        "To arrange for someone to have a seat on a plane.",
                        "To arrange something on a particular date."
                }
        );
    
    private final String name;
    private final String[] keys;
    private final String[] values;
    
    
    private DictionaryEnum(String name, String[] keys, String[] values) {
        this.name = name;
        this.keys = keys;
        this.values = values;
    }
    
    public String getName() {
        return name;
    }


    public String[] getKeys() {
        return keys;
    }


    public String[] getValues() {
        return values;
    }
    
    /**
     * Will return the fitting DictionaryEnum for the passed name, or null if not found
     * @param name
     * @return
     */
    public static DictionaryEnum getByName(String name) {
        for (DictionaryEnum dictionaryEnum : values()) {
            if(dictionaryEnum.getName().equalsIgnoreCase(name)) {
                return dictionaryEnum;
            }
        }
        return null;
    }
    
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter command:");
        String input = scanner.nextLine();
        String[] keywords = input.split(" ");
        String name = keywords[0];
        String command = keywords[1];
        
        // 1. Use our static method to get the fitting enum:
        DictionaryEnum dictionaryEnum = DictionaryEnum.getByName(name);
        if (dictionaryEnum == null) {
            // if the returned object was null no fitting match was found
            System.out.println("NO ENUM FOUND!");
        } else {
            // 2. We found a fitting enum object! Lets use that object to iterate over its contents
            if ("reverse".equals(command)) {
                for (int i = dictionaryEnum.getKeys().length - 1; i >= 0; i--) {
                    String key = dictionaryEnum.getKeys()[i];
                    String value = dictionaryEnum.getValues()[i];
                    System.out.println(dictionaryEnum.getName() + " [" + key + "] : " + value);
                }
            } else {
                for (int i = 0; i < dictionaryEnum.getKeys().length; i++) {
                    String key = dictionaryEnum.getKeys()[i];
                    String value = dictionaryEnum.getValues()[i];
                    System.out.println(dictionaryEnum.getName() + " [" + key + "] : " + value);
                }
            }
        }
        
        scanner.close();
    }
}

公共枚举字典yenum{
箭(
“箭”，
新字符串[]{
“名词”
},
新字符串[]{
“这里有一个箭头：-=>>”
}
),
书(
“书”，
新字符串[]{
“名词”，
“名词”，
“动词”，
“动词”
},
新字符串[]{
“一套书页。”，
“以印刷或电子形式出版的书面作品。”，
“安排某人坐飞机。”，
“在特定日期安排某事。”
}
);
私有最终字符串名；
私有最终字符串[]密钥；
私有最终字符串[]值；
private DictionaryEnum（字符串名称、字符串[]键、字符串[]值）{
this.name=名称；
this.keys=keys；
这个值=值；
}
公共字符串getName（）{
返回名称；
}
公共字符串[]getKeys（）{
返回键；
}
公共字符串[]getValues（）{
返回值；
}
/**
*将返回传递名称的fitting DictionaryEnum，如果找不到，则返回null
*@param name
*@返回
*/
公共静态字典num getByName（字符串名称）{
对于（DictionaryEnum DictionaryEnum:values（））{
if（dictionaryEnum.getName（）.equalsIgnoreCase（名称））{
返回字典yenum；
}
}
返回null；
}
公共静态void main（字符串[]args）{
扫描仪=新的扫描仪（System.in）；
System.out.println（“输入命令：”）；
字符串输入=scanner.nextLine（）；
字符串[]关键字=输入。拆分（“”）；
字符串名称=关键字[0]；
字符串命令=关键字[1]；
//1.使用我们的静态方法获取拟合枚举：
DictionaryEnum DictionaryEnum=DictionaryEnum.getByName（名称）；
如果（dictionaryEnum==null）{
//如果返回的对象为null，则找不到拟合匹配项
System.out.println（“未找到枚举！”）；
}否则{
//2.我们找到了一个合适的枚举对象！让我们使用该对象对其内容进行迭代
如果（“反向”。等于（命令））{
对于（int i=dictionaryEnum.getKeys（）.length-1；i>=0；i--）{
String key=dictionaryEnum.getKeys（）[i]；
字符串值=dictionaryEnum.getValues（）[i]；
System.out.println（dictionaryEnum.getName（）+“[”+键+“]：“+值）；
}
}否则{
for（int i=0；i

现在，我添加的大部分内容都是简单的getter/setter和构造函数，它们应该或多或少与您所拥有的内容相同。您可能感兴趣的是我添加的静态方法

publicstaticdictionaryenumgetbyname（stringname）

。此方法接受一个字符串参数，然后遍历所有存在的枚举对象。它将传递的参数与name字段进行比较，如果相等（忽略大小写），它将返回该枚举对象。如果循环在没有找到匹配项的情况下完成运行，它将返回null

所以调用该方法，比如

DictionaryEnum.getByName（“箭头”）

将返回对象

DictionaryEnum.ARROW

有许多不同的方法可以通过输入找到所需的枚举（另一个示例请参见Fabian Tschachtli的答案），但在执行其他操作之前，需要先获得正确的枚举对象

---

然后，您所要做的就是使用找到的枚举对象在数组字段上正常或反向迭代。您可以在我添加的主方法中看到所有这些，并运行代码本身。

由于您发布了一个不完整的枚举，我不得不自己完成缺少的部分。因此请记住，枚举字段名称和方法可能与代码中的名称不同：

public enum DictionaryEnum {
        ARROW(
                "Arrow",
                new String[] {
                        "noun"
                },
                new String[] {
                        "Here is one arrow: <IMG> -=>> </IMG>"
                }
        ),
        BOOK(
                "Book",
                new String[]{
                        "noun",
                        "noun",
                        "verb",
                        "verb"
                },
                new String[]{
                        "A set of pages.",
                        "A written work published in printed or electronic form.",
                        "To arrange for someone to have a seat on a plane.",
                        "To arrange something on a particular date."
                }
        );
    
    private final String name;
    private final String[] keys;
    private final String[] values;
    
    
    private DictionaryEnum(String name, String[] keys, String[] values) {
        this.name = name;
        this.keys = keys;
        this.values = values;
    }
    
    public String getName() {
        return name;
    }


    public String[] getKeys() {
        return keys;
    }


    public String[] getValues() {
        return values;
    }
    
    /**
     * Will return the fitting DictionaryEnum for the passed name, or null if not found
     * @param name
     * @return
     */
    public static DictionaryEnum getByName(String name) {
        for (DictionaryEnum dictionaryEnum : values()) {
            if(dictionaryEnum.getName().equalsIgnoreCase(name)) {
                return dictionaryEnum;
            }
        }
        return null;
    }
    
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("Enter command:");
        String input = scanner.nextLine();
        String[] keywords = input.split(" ");
        String name = keywords[0];
        String command = keywords[1];
        
        // 1. Use our static method to get the fitting enum:
        DictionaryEnum dictionaryEnum = DictionaryEnum.getByName(name);
        if (dictionaryEnum == null) {
            // if the returned object was null no fitting match was found
            System.out.println("NO ENUM FOUND!");
        } else {
            // 2. We found a fitting enum object! Lets use that object to iterate over its contents
            if ("reverse".equals(command)) {
                for (int i = dictionaryEnum.getKeys().length - 1; i >= 0; i--) {
                    String key = dictionaryEnum.getKeys()[i];
                    String value = dictionaryEnum.getValues()[i];
                    System.out.println(dictionaryEnum.getName() + " [" + key + "] : " + value);
                }
            } else {
                for (int i = 0; i < dictionaryEnum.getKeys().length; i++) {
                    String key = dictionaryEnum.getKeys()[i];
                    String value = dictionaryEnum.getValues()[i];
                    System.out.println(dictionaryEnum.getName() + " [" + key + "] : " + value);
                }
            }
        }
        
        scanner.close();
    }
}

公共枚举字典yenum{
箭(
“箭”，
新字符串[]{
“名词”
},
新字符串[]{
“这里有一个箭头：-=>>”
}