@JsonSerialize和JsonSerializer的用法 [英] Usage of @JsonSerialize and JsonSerializer

问题描述

我有一个Spring MVC应用程序，它要求我将某个实体列表的id和名称转换为具有特定格式的JSON对象数组，并在某个请求上输出。也就是说，我需要一个像这样的JSON对象数组：

I have a Spring MVC application that requires me to translate the id's and names of a list of a certain entity to an array of JSON objects with specific formatting, and output that on a certain request. That is, I need an array of JSON objects like this:

{
     label: Subject.getId()
     value: Subject.getName()
}

为了便于jQuery使用自动完成插件。

For easy use with the jQuery Autocomplete plugin.

所以在我的控制器中，我写了以下内容：

So in my controller, I wrote the following:

@RequestMapping(value = "/autocomplete.json", method = RequestMethod.GET)
@JsonSerialize(contentUsing=SubjectAutocompleteSerializer.class)
public @ResponseBody List<Subject> autocompleteJson() {
    return Subject.findAllSubjects();
}

// Internal class
public class SubjectAutocompleteSerializer extends JsonSerializer<Subject> {

    @Override
    public void serialize(Subject value, JsonGenerator jgen, SerializerProvider provider)
            throws IOException, JsonProcessingException {
        jgen.writeStartObject();
        jgen.writeStringField("label", value.getId().toString());
        jgen.writeStringField("value", value.getName());
        jgen.writeEndObject();
    }

}

我回来的JSON，是Jackson推断的默认序列化。我的自定义序列化程序似乎完全被忽略了。显然问题是@JsonSerialize或JsonSerializer的使用不正确，但我无法在任何地方找到这些内容的正确用法。

The JSON I get back however, is the default serialization inferred by Jackson. My custom serializer seems to be completely ignored. Obviously the problem is incorrect usage of @JsonSerialize or JsonSerializer, but I could not find proper usage of these within context anywhere.

使用Jackson实现我想要的序列化的正确方法是什么？请注意，在这种情况下，实体仅以这种方式序列化是很重要的，并且在其他地方打开其他序列化

What is the proper way to use Jackson to achieve the serialization I want? Please note that it's important that the entities are only serialized this way in this context, and open to other serialization elsewhere

推荐答案

@JsonSerialize应该在被序列化的类而不是控制器上设置。

@JsonSerialize should be set on the class that's being serialized not the controller.

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