SpringBoot 之SpringMVC 转换对象为JSON存在 null.

问题背景:

对象结构:

public class result<t> {
    private int code;
    private string msg;
    private string errmsg;
    private t data;
}

后台应该返回结果:

{
    "code": 200,
    "msg": "ok",
    "errmsg": ""
}

问题冲突:

后台实际返回结果:

{
    "code": 200,
    "msg": "ok",
    "errmsg": "",
    "data": null
}

问题解决方案:

@configuration
public class jsonconfig {
    @bean
    public mappingjackson2httpmessageconverter mappingjackson2httpmessageconverter(){
        objectmapper objectmapper = new objectmapper();
        //设置过滤掉null值得属性.
        objectmapper.setserializationinclusion(jsoninclude.include.non_null);
        return new mappingjackson2httpmessageconverter(objectmapper);
    }
}

问题总结:

默认情况下，mappingjackson2httpmessageconverter 不会过滤掉null值,需要手动设置serializationinclusion属性为jsoninclude.include.non_null.