看到项目中的DateTimeFormat和JsonFormat就头大

刚来这家公司的时候, 发现很多同事还在用这种方式写代码

当时以为是偶然, 刚才在群里发现还有好多人在交流应当加哪些注解, 声明时区问题.

当写一个东西感到麻烦的时候, 那么大概率是有低成本的更优解的

分以下两种情况来处理

请求体

使用Jackson, 仅保留时间相关配置

package kim.nzxy.ly.common.config;

import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

/**
 * JSON相关
 *
 * @author ly-chn
 */
@Configuration
public class JacksonConfig {
    @Bean
    public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer() {
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

        return builder -> {
            builder.serializerByType(LocalDateTime.class, new LocalDateTimeSerializer(dtf))
                    .deserializerByType(LocalDateTime.class, new LocalDateTimeDeserializer(dtf))
                	// 以下代码"可以, 但没必要"
                    .serializerByType(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ISO_LOCAL_TIME))
                    .deserializerByType(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ISO_LOCAL_TIME))
                    .serializerByType(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ISO_LOCAL_DATE))
                    .deserializerByType(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ISO_LOCAL_DATE))
        };
    }
}

请求行

用于query string / request parameter

package kim.nzxy.ly.common.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.format.datetime.standard.DateTimeFormatterRegistrar;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import java.time.format.DateTimeFormatter;

/**
 * request parameter date time format
 * @author ly-chn
 */
@Configuration
public class DateTimeFormatConfig implements WebMvcConfigurer {
    @Override
    public void addFormatters(FormatterRegistry registry) {
        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        DateTimeFormatterRegistrar registrar = new DateTimeFormatterRegistrar();
        registrar.setDateTimeFormatter(dateTimeFormatter);
        // 以下代码"可以, 但没必要"
        registrar.setDateFormatter(DateTimeFormatter.ISO_LOCAL_DATE);
        registrar.setTimeFormatter(DateTimeFormatter.ISO_LOCAL_TIME);
        registrar.registerFormatters(registry);
    }
}

yml方式配置, 任选其一即可

spring: 
  mvc:
    format:
      date-time: yyyy-MM-dd HH:mm:ss
      # 以下代码"可以, 但没必要"
      date: yyyy-MM-dd
      time: HH:mm:ss

使用示例

实体类

package kim.nzxy.ly.test.entity;

import lombok.Data;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;

@Data
public class Temp {
    private LocalDateTime ldt;
    private LocalDate ld;
    private LocalTime lt;
}

controller中接收

package kim.nzxy.ly.controller;

import kim.nzxy.ly.modules.system.entity.Temp;
import org.springframework.web.bind.annotation.*;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;

@RestController
@RequestMapping("temp")
public class TempController {
    @GetMapping("1")
    public Temp test1(LocalDateTime ldt, LocalDate ld, LocalTime lt) {
        return new Temp(ldt, ld, lt);
    }

    @GetMapping("2")
    public Temp test2(Temp temp) {
        return temp;
    }

    @PostMapping("3")
    public Temp test3(@RequestBody Temp temp) {
        return temp;
    }
}

test.rest

### 逐个传输
GET http://localhost:8937/temp/1?ldt=2006-01-02 15:04:05&ld=2006-01-02&lt=15:04


### 实体类接收
GET http://localhost:8937/temp/2?ldt=2006-01-02 15:04:05&ld=2006-01-02&lt=15:04


### json请求体
POST http://localhost:8937/temp/3
Content-Type: application/json

{
  "ldt": "2006-01-02 15:04:05",
  "ld": "2006-01-02",
  "lt": "15:04"
}

总结

1. LocalTime和LocalDate的格式一般不用配置, 默认都是常用格式

2. DateTimeFormatter.ISO_LOCAL_TIME和DateTimeFormatter.ofPattern(String pattern)区别

   这个可以查看其源码, ISO_LOCAL_TIME是可以解析"03:04" / "03:04:05" / "03:04:05.111222333"(时分, 时分秒, 时分秒+毫秒)这些格式的, 如果直接使用ofPattern则不行

3. Date类型怎么处理

   首先不建议使用Date类型, 如果有需要, 尽量改成Local*, 除非后端只接受同一种日期格式:

   1. yml配置参考上方yml方式配置

   2. 请求行配置尝试新建配置类, 继承WebBindingInitializer, 然后registerCustomEditor

   3. Jackson yml

      jackson:
       date-format: yyyy-MM-dd HH:mm:ss
       # Asia/Shanghai(CST)
       time-zone: GMT+8