java中枚举的使用详解

项目开发中常用枚举做常量参数的使用：今天我们分享一下

1、空对象枚举：

//颜色枚举
public enum Colors {  
  RED, GREEN, BLANK, YELLOW  
}  

2、单个对象枚举：

//请求头设置
public enum RequestHeaderEnum {
    language("en"),
    token("token"),
    uid("X-UID"),
    lang("Accept-Language"),
    device("X-Devices"),
    version("X-Version"),
    flag("true");

    private String head;

    RequestHeaderEnum(String head) {
        this.head = head;
    }

    public String head() {
        return head;
    }
}

3、多参数枚举：

import java.util.HashMap;
import java.util.Map;


public enum  NanTestEnum {

    
    talk("token","akey","aname"),
    flag("fd","okey","oname"),
    cookie("uuid","nkey","nanname");

    private String head;
    private String userKey;
    private String userName;

    NanTestEnum(String head,String userKey,String userName) {
        this.head = head;
        this.userKey = userName;
        this.userName = userName;
    }

    
    public void setHead(String head){
        this.head = head;
    }
    public String getHead() {
        return head;
    }
    public void setUserKey(String userKey){
        this.userKey = userName;
    }
    public String getUserKey() {
        return userKey;
    }
    public void setUserName(String userName){
        this.userName = userName;
    }
    public String getUserName() {
        return userName;
    }

    
    private static final Map nanEnumMap = new HashMap<>();
    static {
        for (NanTestEnum nanTestEnum : NanTestEnum.values()){
            nanEnumMap.put(nanTestEnum.getHead(),nanTestEnum);
        }
    }

    
    private static final Map userKeyMap = new HashMap<>();
    static {
        for (NanTestEnum nanTestEnum : NanTestEnum.values()){
            userKeyMap.put(nanTestEnum.getHead(),nanTestEnum.getUserKey());
        }
    }

    
    private static final Map usernameMap = new HashMap<>();
    static {
        for (NanTestEnum nanTestEnum : NanTestEnum.values()){
            usernameMap.put(nanTestEnum.getHead(),nanTestEnum.getUserName());
        }
    }

    
    public static NanTestEnum gettestEnum(String head){
        return nanEnumMap.get(head);
    }

    
    public static String getTestUserKey(String head){
        return userKeyMap.get(head);
    }

}

4、main方法测试结果：

到此、枚举使用分享完毕，下次我们系统分享一下枚举原理，敬请期待！