Spring Boot bind @Value to Enum case insensitive

问题:

I have an application.properties with a property:

custom.property=test 

I have a field in the class:

@Value("${custom.property}") protected Property property; 

I have an enum:

   public enum Property {      A,     AB,     ABC,     ABCD,     ABCDE; } 

When I'm running application with a

custom.property=abc (lower case) 

I have an error:

Cannot convert value of type [java.lang.String] to required type [com.blabla.domain.enums.Property]: no matching editors or conversion strategy found.

custom.property=ABC (upper case) 

Works fine.

Is there a way to bind the value case insensitive? Like ABC, Abc, abc any match should work. Thanks in advance.

NOTE: I saw this question - Spring 3.0 MVC binding Enums Case Sensitive but in my case I have over 10 enums/values (and expect to have more) classes and to implement 10 different custom property binders would be painful, I need some generic solution.

回答1:

@Value and @ConfigurationProperties features do not match. I couldn't stress enough how @ConfigurationProperties is superior.

First, you get to design your configuration in a simple POJO that you can inject wherever you want (rather than having expressions in annotation that you can easily break with a typo). Second, the meta-data support means that you can very easily get auto-completion in your IDE for your own keys.

And finally, the relaxed binding described in the doc only applies to @ConfigurationProperties. @Value is a Spring Framework feature and is unaware of relaxed binding. We intend to make that more clear in the doc.

TL;DR abc works with @ConfigurationProperties but won't with @Value.

回答2:

The values are case-sensitive (consider keys or passwords injected from the environment), and the relaxed binding applies only to the keys. Java enum names are also case-sensitive (A and a are distinct values), and you wouldn't want to squash case.

Just use the correct case in your configuration properties.

回答3:

In a practical world, this works....

public enum Property {     A, a     AB, ab,     ABC, abc,     ABCD, abcd,     ABCDE, abcde;       public boolean isA() {         return this.equals(A) || this.equals(a);     }      public boolean isAB() {         return this.equals(AB) || this.equals(ab);     }      ...etc...  } 

..although this does break the principle of the enum!

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