Java enum 对枚举元素的赋值和取值方式

package edu.fjnu501.bankenum;
 
public enum Trade {
    save("0"), withdraw("1");
 
    private String type;
 
    Trade(String s) {
        type = s;
    }
 
    public String getType() {
        return this.type;
    }
 
}

if (Trade.withdraw.getType().equals("1")) {
    // true
}

public enum Level {
	LOW("0", "level.LOW"),
	MEDIUM("1", "level.MEDIUM"),
	HIGH("2", "level.HIGH");
 
	private String value;
	private String description;
 
	private Level(String value, String description) {
		this.value = value;
		this.description = description;
	}
 
	public String getValue() {
		return this.value;
	}
 
	public String getDescription() {
		return messageSource.getMessage(description, null, description, null);
	}
 
    //spring 框架的类
	private MessageSource messageSource;
 
	public Level setMessageSource(MessageSource messageSource) {
		this.messageSource = messageSource;
		return this;
	}

@Component
	public  class EnumValuesInjectionService {
 
		@Autowired
		private MessageSource messageSource;
 
		//通过静态内部类的方式注入到bean，并 赋值到枚举中。
		@PostConstruct
		public void postConstruct() {
 
			for (Level level : EnumSet.allOf(Level.class)) {
				level.setMessageSource(messageSource);
			}
		}
	}

level.LOW=低
level.MEDIUM=中
level.HIGH=高