解决Jackson2反序列化LocalDateTime报错

今天在整合redis和spring boot的时候，遇到了一个错误，记录一下。

报错如下：

could not read json: cannot construct instance of `java.time.localdatetime` (no creators, like default construct, exist): cannot deserialize from object value (no delegate- or property-based creator)

查看后发现是数据从redis中取出时，jackson2反序列化数据处理localdatetime类型时出错，原因是：jackson2在序列化localdatetime时输出的不是普通的字符串时间格式，而是如下所示的格式（普通时间格式：2019-02-27 12:10:17）

{
    "date": {
        "year": 2019,
        "month": "february",
        "day": 27,
        "dayofmonth": 27,
        "dayofweek": "wednesday",
        "era": [
            "java.time.chrono.isoera",
            "ce"
        ],
        "dayofyear": 58,
        "leapyear": false,
        "chronology": {
            "id": "iso",
            "calendartype": "iso8601"
        },
        "prolepticmonth": 24229,
        "monthvalue": 2
    },
    "time": {
        "hour": 12,
        "minute": 10,
        "second": 17,
        "nano": 0
    },
    "month": "february",
    "year": 2019,
    "dayofmonth": 27,
    "dayofweek": "wednesday",
    "dayofyear": 58,
    "hour": 12,
    "minute": 10,
    "nano": 0,
    "second": 17,
    "monthvalue": 2,
    "chronology": [
        "java.time.chrono.isochronology",
        {
            "id": "iso",
            "calendartype": "iso8601"
        }
    ]
}

view code

 

所以是jackson2序列化localdatetime跟我们所预想的不一致，将注册给redis的序列化模板修改成以下就行

 1 @configuration
 2 public class redisconfig {
 3 
 4     /**
 5      * 定义 userredistemplate ，指定序列化和反序列化的处理类
 6      *
 7      * @param factory redis连接工厂
 8      * @return 模板
 9      */
10     @bean("userredistemplate")
11     public redistemplate<string, user> userredistemplate(redisconnectionfactory factory) {
12         redistemplate<string, user> template = new redistemplate<>();
13         template.setconnectionfactory(factory);
14         jackson2jsonredisserializer<user> j2jrs = new jackson2jsonredisserializer<>(user.class);
15         objectmapper om = new objectmapper();
16         om.setvisibility(propertyaccessor.all, jsonautodetect.visibility.any);
17         // 解决jackson2无法反序列化localdatetime的问题
18         om.disable(serializationfeature.write_dates_as_timestamps);
19         om.registermodule(new javatimemodule());
20         om.enabledefaulttyping(objectmapper.defaulttyping.non_final, jsontypeinfo.as.property);
21         j2jrs.setobjectmapper(om);
22         // 序列化 value 时使用此序列化方法
23         template.setvalueserializer(j2jrs);
24         template.sethashvalueserializer(j2jrs);
25         // 序列化 key 时
26         stringredisserializer srs = new stringredisserializer();
27         template.setkeyserializer(srs);
28         template.sethashkeyserializer(srs);
29         template.afterpropertiesset();
30         return template;
31     }
32 }

主要是加上标红的那两句

 

参考文档：

genericjackson2jsonredisserializer 反序列化问题