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This article mainly introduces the SpringBoot time formatting method has what related knowledge, the content is detailed and easy to understand, the operation is simple and fast, has a certain reference value, I believe you read this SpringBoot time formatting method which article will have some harvest, let's take a look at it.

Time formatting is frequently used in projects. When our API interface returns results, one of the date field properties needs to be specially formatted, which is usually handled by SimpleDateFormat tools.

SimpleDateFormat dateFormat = new SimpleDateFormat ("yyyy-MM-dd"); Date stationTime = dateFormat.parse (dateFormat.format (PayEndTime ()

But once there are more places to deal with, not only frequent CV operations, but also generate a lot of repeated bloated code, and at this time, if the time format can be configured uniformly, you can save more time to focus on business development.

Many people may think that unifying the formatting time is very simple, just configure it like this, but in fact this method only works for date types.

Spring.jackson.date-format=yyyy-MM-dd HH:mm:ssspring.jackson.time-zone=GMT+8

The time and date API used in many projects is confusing, java.util.Date, java.util.Calendar, and java.time LocalDateTime all exist, so global time formatting must be compatible with both new and old API.

Take a look at the format of the time field returned by the interface before configuring the global time format.

@ Datapublic class OrderDTO {private LocalDateTime createTime; private Date updateTime;}

Obviously does not meet the display requirements on the page

1. @ JsonFormat comments

The @ JsonFormat annotation cannot be strictly called global time formatting, but should be called partial formatting, because the @ JsonFormat annotation needs to be used in the time field of the entity class, and the corresponding field can only be formatted by using the corresponding entity class.

Datapublic class OrderDTO {@ JsonFormat (locale = "zh", timezone = "GMT+8", pattern = "yyyy-MM-dd") private LocalDateTime createTime; @ JsonFormat (locale = "zh", timezone = "GMT+8", pattern = "yyyy-MM-dd HH:mm:ss") private Date updateTime;}

After the field is annotated with @ JsonFormat, the LocalDateTime and Date times are formatted successfully.

2. @ JsonComponent comment (recommended)

This is a method I personally recommend. I saw earlier that using the @ JsonFormat annotation can not completely achieve global time formatting, so next we use the @ JsonComponent annotation to customize a global formatting class to format Date and LocalDate types respectively.

@ JsonComponentpublic class DateFormatConfig {@ Value ("${spring.jackson.date-format:yyyy-MM-dd HH:mm:ss}") private String pattern; / * * @ author xiaofu * @ description date type global time format * @ date 2020-8-31 18:22 * / @ Bean public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilder () {return builder-> {TimeZone tz = TimeZone.getTimeZone ("UTC") DateFormat df = new SimpleDateFormat (pattern); df.setTimeZone (tz); builder.failOnEmptyBeans (false) .failOnUnknownProperties (false). SecreturesToDisable (SerializationFeature.WRITE_DATES_AS_TIMESTAMPS) .dateFormat (df);} } / * * @ author xiaofu * @ description LocalDate type global time format * @ date 18:22 on 2020-8-31 * / @ Bean public LocalDateTimeSerializer localDateTimeDeserializer () {return new LocalDateTimeSerializer (DateTimeFormatter.ofPattern (pattern));} @ Bean public Jackson2ObjectMapperBuilderCustomizer jackson2ObjectMapperBuilderCustomizer () {return builder-> builder.serializerByType (LocalDateTime.class, localDateTimeDeserializer ());}}

It works when you see that both Date and LocalDate time types are formatted successfully.

But there is another problem. In actual development, what if I have a field that does not want to use the time style set by global formatting, and I want to customize the format?

Then you need to use it in conjunction with the @ JsonFormat annotation.

Datapublic class OrderDTO {@ JsonFormat (locale = "zh", timezone = "GMT+8", pattern = "yyyy-MM-dd") private LocalDateTime createTime; @ JsonFormat (locale = "zh", timezone = "GMT+8", pattern = "yyyy-MM-dd") private Date updateTime;}

From the results, we can see that the @ JsonFormat annotation has a higher priority and will be dominated by the time format of the @ JsonFormat annotation.

3. @ Configuration comment

This global configuration is implemented in the same way as above.

"

Note: after using this configuration, the field manual configuration @ JsonFormat annotation will no longer take effect.

"

@ Configurationpublic class DateFormatConfig2 {@ Value ("${spring.jackson.date-format:yyyy-MM-dd HH:mm:ss}") private String pattern; public static DateFormat dateFormat = new SimpleDateFormat ("yyyy-MM-dd HH:mm:ss"); @ Bean @ Primary public ObjectMapper serializingObjectMapper () {ObjectMapper objectMapper = new ObjectMapper (); JavaTimeModule javaTimeModule = new JavaTimeModule (); javaTimeModule.addSerializer (LocalDateTime.class, new LocalDateTimeSerializer ()) JavaTimeModule.addDeserializer (LocalDateTime.class, new LocalDateTimeDeserializer ()); objectMapper.registerModule (javaTimeModule); return objectMapper } / * * @ author xiaofu * @ description Date time type replacement * @ date 17:25 on 2020-9-1 * / @ Component public class DateSerializer extends JsonSerializer {@ Override public void serialize (Date date, JsonGenerator gen, SerializerProvider provider) throws IOException {String formattedDate = dateFormat.format (date); gen.writeString (formattedDate) }} / * * @ author xiaofu * @ description Date time type replacement * @ date 17:25 on 2020-9-1 * / @ Component public class DateDeserializer extends JsonDeserializer {@ Override public Date deserialize (JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {try {return dateFormat.parse (jsonParser.getValueAsString ()) } catch (ParseException e) {throw new RuntimeException ("Could not parse date", e) } / * * @ author xiaofu * @ description LocalDate time type replacement * @ date 17:25 on 2020-9-1 * / public class LocalDateTimeSerializer extends JsonSerializer {@ Override public void serialize (LocalDateTime value, JsonGenerator gen, SerializerProvider serializers) throws IOException {gen.writeString (value.format (DateTimeFormatter.ofPattern (pattern) }} / * * @ author xiaofu * @ description LocalDate time type replacement * @ date 17:25 on 2020-9-1 * / public class LocalDateTimeDeserializer extends JsonDeserializer {@ Override public LocalDateTime deserialize (JsonParser p, DeserializationContext deserializationContext) throws IOException {return LocalDateTime.parse (p.getValueAsString (), DateTimeFormatter.ofPattern (pattern)) This is the end of the article on "what are the ways to format SpringBoot time?" Thank you for reading! I believe you all have a certain understanding of the knowledge of "what are the methods of SpringBoot time formatting". If you want to learn more, you are welcome to follow the industry information channel.

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