java - SpringMVC中使用jackson返回json时如何将枚举转为json

Question

SpringMVC中使用jackson返回json时如何将枚举转为json

在网上搜过，给出的方案是在要转换的枚举的get方法上加上@JsonValue注解，我加上后报了错
下面是我错误的示例：
StatusEnum：

IndexController：

POM.xml中jackson与Spring的版本号：

报的错：

Answer 1

My approach is to write a public method to convert to Map
Implement it however convenient it is. In fact, I think the annotation should be placed on the get method of the enumeration instance

public class Result {
    private StatusEnum status;
    ...
    
    @JsonValue
    public StatusEnum getStatus() {
        return status;
    }
    
    public void setStatus(status) {
        this.status = status;
    }
}

I haven’t used this before, so I don’t know much about it, but you can try it.
I couldn’t resist my curiosity and tried it. . . The one above is not feasible. . . But don’t use @JsonValue

@JsonFormat(shape = JsonFormat.Shape.OBJECT)
public enum StatusEnum {
    STATUS_ERROR("200", "OK"),
    STATUS_SUCCESS(404, "Not Found");
    
    private Stringcode;
    private String msg;
    
    private Status(String code, String msg) {...}

    //getter & setter
    ...
}

Personal test, it works

Answer 2

enum默认jackson只能序列化为索引和枚举名称，如果你需要返回{} json object 需要自已实现Serializer
Jdk8Module 参考这个实现自己对StatusEnumDo the processing.

Answer 3

Reference: http://blog.csdn.net/sdyy321/...

You can take a look at the following points:

1. SerializationFeature.WRITE_ENUMS_USING_TO_STRING；

2. @JsonSerialize和@JsonDeserialize；

3. @JsonCreator

If you just need serialization, you can use 1 and @JsonSerialize to implement it simply. The former is simple and the latter is flexible;
If you need deserialization, you can use @JsonDeserialize code> and @JsonSerialize实现，前者简单，后者灵活；
如果需要反序列化，那可以用@JsonDeserialize和@JsonCreator, the former is flexible and the latter is simple :)