Java Generic Enum类使用Reflection [英] Java Generic Enum class using Reflection

问题描述

在我们的代码中，有10个枚举类具有相同的模板代码，每次都有一个新的枚举类需要被创建时。

In our code there are 10's of enum classes with same template code pasted each and every time when ever a new enum class needs to be created.

需要一种方式以通用方式避免重复此代码。

Need a way to generic way to avoid duplication of this code.

以下是几个相同的枚举类

Below are couple of same enums classes

Class-1

 public enum AccountStatus {

ACTIVE("ACTIVE", 1), 
INACTIVE("INACTIVE", 2);

private final int value;

private final String key;

AccountStatus(String key, int value) {
    this.value = value;
    this.key = key;
}

public int getValue() {
    return this.value;
}

public String getKey() {
    return this.key;
}

@Override
public String toString() {
    return String.valueOf(this.value);
}

@JsonCreator
public static AccountStatus create(String key) {
    if (key == null) {
        throw new IllegalArgumentException();
    }
    for (AccountStatus v : values()) {
        if (v.getKey().equalsIgnoreCase(key)) {
            return v;
        }
    }
    throw new IllegalArgumentException();
}

public static AccountStatus fromValue(Integer value) {

    for (AccountStatus type : AccountStatus.values()) {
        if (value == type.getValue()) {
            return type;
        }
    }
    throw new IllegalArgumentException("Invalid enum type supplied");
}

public static AccountStatus fromValue(String key) {

    for (AccountStatus type : AccountStatus.values()) {
        if (type.getKey().equalsIgnoreCase(key)) {
            return type;
        }
    }
    throw new IllegalArgumentException("Invalid enum type supplied");
}
 }

Class-2 / p>

Class-2

      public enum Gender {

MALE("MALE", 1), 
FEMALE("FEMALE", 2);

private final int value;

private final String key;

Gender(String key, int value) {
    this.value = value;
    this.key = key;
}

public int getValue() {
    return this.value;
}

public String getKey() {
    return this.key;
}

@Override
public String toString() {
    return String.valueOf(this.value);
}

@JsonCreator
public static Gender create(String key) {
    if (key == null) {
        throw new IllegalArgumentException();
    }
    for (Gender v : values()) {
        if (v.getKey().equalsIgnoreCase(key)) {
            return v;
        }
    }
    throw new IllegalArgumentException();
}

public static Gender fromValue(Integer value) {

    for (Gender type : Gender.values()) {
        if (value == type.getValue()) {
            return type;
        }
    }
    throw new IllegalArgumentException("Invalid enum type supplied");
}

public static Gender fromValue(String gender) {

    for (Gender type : Gender.values()) {
        if (type.getKey().equalsIgnoreCase(gender)) {
            return type;
        }
    }
    throw new IllegalArgumentException("Invalid enum type supplied");
}

}

需要一个通用的解决方案来处理类中的所有方法。

Need a generic a solution which handles all the methods in class.

推荐答案

我可以看到的两个选项，都涉及到接口。在这两种情况下，您仍然需要为您的枚举创建构造函数并声明这些字段。

Two options that I can see, and both involve interfaces. In either case though, you will still need to make the constructor for your enum and declare the fields.

1. 在您的枚举上实现一个界面 getValue 和 getKey 方法，然后移动创建和 fromValue 方法到一个将枚举类作为参数的实用程序类。例如

1. Implement an interface on your enum for the getValue and getKey methods, and then move the create and fromValue methods to a utility class that takes the enum class as a parameter. e.g.

EnumUtility.create（AccountStatus.class，ACTIVE）;

1. 使用JDK8接口声明将继承到您的枚举中的默认方法实现。

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