爲什麼android studio告訴我enum.valueOf總是正確的？

Question

我有一個奇怪的問題。這是我的枚舉：

enum ErrorInByte{ 
    ERROR_BIT0(3), 
    ERROR_BIT2(4), 
    ERROR_BIT3(5), 
    ERROR_BIT4(7), 
    ERROR_BIT5(13), 
    ERROR_BIT7(15), 

    private int value; 
    ErrorInByte(int value) { 
     this.value = value; 
    } 

    public static ErrorInByte valueOf(int value){ 
     return intToErrorInByte.get(value); 
    } 

    private static final Map<Integer, ErrorInByte> intToErrorInByte= new HashMap<>(); 
    static { 
     for (ErrorInByte type : ErrorInByte.values()) { 
      intToErrorInByte.put(type.value, type); 
     } 
    } 
} 

在我的班級我有一個如果：

int n; 
//Code that changes n to a value 
if(n > 0 && ErrorInByte.valueOf(n) != null){ 
//do stuff... 
} 

爲什麼機器人工作室告訴我，ErrorInByte.valueOf（n）將永遠是真的嗎？我測試了它，併爲ErrorInByte.valueOf(326)它等於空。

警告消息：

This inspection analyzes method control and data flow to report possible conditions that are always true or false, expressions whose value is statically proven to be constant, and situations that can lead to nullability contract violations. 


Variables, method parameters and return values marked as @Nullable or @NotNull are treated as nullable (or not-null, respectively) and used during the analysis to check nullability contracts, e.g. report possible NullPointerException errors. 

More complex contracts can be defined using @Contract annotation, for example: 

@Contract("_, null -> null") — method returns null if its second argument is null 
@Contract("_, null -> null; _, !null -> !null") — method returns null if its second argument is null and not-null otherwise 
@Contract("true -> fail") — a typical assertFalse method which throws an exception if true is passed to it 

The inspection can be configured to use custom @Nullable 
    @NotNull annotations (by default the ones from annotations.jar will be used) 

有什麼辦法去除警告？我討厭警告...

Answer 1

什麼情況是Enums已經有一個非覆蓋能夠valueOf方法。這意味着您實際上正在調用您自己定義的valueOf，但IDE假定它是靜態的valueOf。因此，爲了解決您的問題你有你的方式重命名爲類似

public static ErrorInByte lookUpByCode(int value){ 
     return intToErrorInByte.get(value); 
    }