Add ZonedDateTime and OffsetDateTime support to JobParametersConverter

[thswlsqls]

Expected Behavior

ZonedDateTime and OffsetDateTime should be supported as JobParameters types, similar to LocalDateTime, LocalDate, and LocalTime.

Example usage:

ZonedDateTime scheduleTime = ZonedDateTime.of(2023, 12, 25, 10, 30, 0, 0, ZoneId.of("Asia/Seoul"));
JobParameters parameters = new JobParametersBuilder()
    .addJobParameter("schedule.time", scheduleTime, ZonedDateTime.class, true)
    .toJobParameters();

Current Behavior

Spring Batch currently only provides converters for LocalDateTime, LocalDate, and LocalTime.
ZonedDateTime and OffsetDateTime cannot be used as JobParameters because there are no converters available.

Context

How has this issue affected you?
When working with global services or multi-timezone applications, we need to pass timezone-aware date/time values as JobParameters, but currently only timezone-naive types (LocalDateTime, LocalDate, LocalTime) are supported.

What are you trying to accomplish?

• Execute batch jobs based on specific timezones in global services
• Require both UTC and local timezone in log analysis
• Include timezone information for each country in multi-country services

What other alternatives have you considered?

• Converting to LocalDateTime and storing timezone separately (loses timezone information)
• Using String type and parsing manually (error-prone, not type-safe)
• Using Date with timezone offset (legacy API, not recommended)

Are you aware of any workarounds?
Currently, there is no clean workaround. Users must convert to LocalDateTime and lose timezone information, or use String type which is not type-safe.

Proposed Implementation:

• Add ZonedDateTimeToStringConverter and StringToZonedDateTimeConverter
• Add OffsetDateTimeToStringConverter and StringToOffsetDateTimeConverter
• Register new converters in DefaultJobParametersConverter
• Add related test code

[scordio]

Currently, there is no clean workaround. Users must convert to LocalDateTime and lose timezone information, or use String type which is not type-safe.

That's not entirely true. In an average Spring Boot application, this conversion capability could be obtained out of the box when defining a DefaultFormattingConversionService bean in the Spring context:

import org.springframework.format.support.DefaultFormattingConversionService;

@Bean
DefaultFormattingConversionService conversionService() {
  return new DefaultFormattingConversionService();
}

This allows the use of job parameters like the following:

import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.format.annotation.DateTimeFormat.ISO;

@Bean
@StepScope
ItemReader<Item> itemReader(@Value("#{jobParameters['targetDate']}") @DateTimeFormat(iso = ISO.DATE) LocalDate targetDate) {
  ...
}

The same should also work with ZonedDateTime and OffsetDateTime.

Nevertheless, it would be nice if Spring Batch would offer this out of the box.

• Register new converters in DefaultJobParametersConverter

As Spring Batch already depends on spring-context, what about instantiating a DefaultFormattingConversionService instead of DefaultConversionService in the DefaultJobParametersConverter constructor?

spring-batch/spring-batch-core/src/main/java/org/springframework/batch/core/converter/DefaultJobParametersConverter.java

Line 79 in 2cc7890

DefaultConversionService conversionService = new DefaultConversionService();

Some existing custom converters in Spring Batch might also become obsolete.