使用类名作为JSON Jackson序列化的根密钥 [英] Use class name as root key for JSON Jackson serialization

问题描述

假设我有一个pojo：

Suppose I have a pojo:

import org.codehaus.jackson.map.*;

public class MyPojo {
    int id;
    public int getId()
    { return this.id; }

    public void setId(int id)
    { this.id = id; }

    public static void main(String[] args) throws Exception {
        MyPojo mp = new MyPojo();
        mp.setId(4);
        ObjectMapper mapper = new ObjectMapper();
        mapper.configure(SerializationConfig.Feature.WRAP_ROOT_VALUE, true);
        System.out.println(mapper.getSerializationConfig().isEnabled(SerializationConfig.Feature.WRAP_ROOT_VALUE));
        System.out.println(mapper.writeValueAsString(mp));
    }
}

当我使用Jackson ObjectMapper进行序列化时，我得到了

When I serialize using the Jackson ObjectMapper, I just get

true
{"id":4}

但我想要

true
{"MyPojo":{"id":4}}

我到处搜索过，Jacksons的文档真的很棒没有组织，大多过时了。

I've searched all over, Jacksons documentation is really unorganized and mostly out of date.

推荐答案

通过在课程级别添加jackson注释 @JsonTypeInfo ，你可以有预期的输出。我刚刚在你的班级中添加了无变化。

By adding the jackson annotation @JsonTypeInfo in class level you can have the expected output. i just added no-changes in your class.

package com.test.jackson;

import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;

import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.JsonTypeInfo.As;
import com.fasterxml.jackson.annotation.JsonTypeInfo.Id;

@JsonTypeInfo(include=As.WRAPPER_OBJECT, use=Id.NAME)
public class MyPojo {
    // Remain same as you have
}

输出：

{
    "MyPojo": {
        "id": 4
    }
}

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