How to globally configure `@DateTimeFormat` pattern in Spring Boot?

@britter: thanks.

spring.mvc.date-format= # Date format to use. For instance, dd/MM/yyyy works fine with Spring Boot 2.1.0.x

See # SPRING MVC (WebMvcProperties) properties.

UPDATE: But it doen't work for Spring Data Rest params ...

You can use spring.mvc.format.date, spring.mvc.format.time and spring.mvc.format.date-time

For example:
spring.mvc.format.time=HH:mm:ss
spring.mvc.format.date=iso
spring.mvc.format.date-time=iso-offset

as in the example above, you can use shortcuts iso аnd iso-offset from spring boot 2.4.1

This is currently not easily possible (e.g. by setting a simple configuration property), see #5523. The best solution I found so far is to register a Formatter<LocalDate>. This will also work with optional parameters modeled as Optional<LocalDate>:

  @Bean
  public Formatter<LocalDate> localDateFormatter() {
    return new Formatter<LocalDate>() {
      @Override
      public LocalDate parse(String text, Locale locale) throws ParseException {
        return LocalDate.parse(text, DateTimeFormatter.ISO_DATE);
      }

      @Override
      public String print(LocalDate object, Locale locale) {
        return DateTimeFormatter.ISO_DATE.format(object);
      }
    };
  }

It may become possible to set this using a configuration property when my proposal in #9930 has been merged.