Cannot use LocaleAware specs with date format config

[cschierle]

There are some specs supporting date fields that are also LocaleAware. When providing a config with a custom date format string (e.g. @Spec(config = {"dd.MM.yyyy"}), these specs cannot be initialized for incoming requests running into this error:

jakarta.servlet.ServletException: Request processing failed: java.lang.IllegalArgumentException: Invalid locale format: dd.MM.yyyy

	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:892)
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:633)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:874)
	at org.springframework.test.web.servlet.TestDispatcherServlet.service(TestDispatcherServlet.java:72)
	at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:723)
	at org.springframework.mock.web.MockFilterChain$ServletFilterProxy.doFilter(MockFilterChain.java:160)
	at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:127)
	at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:199)
	at net.kaczmarzyk.EqualIgnoreCaseE2eTest.findsByFormattedDateValueIgnoringCase(EqualIgnoreCaseE2eTest.java:122)
Caused by: java.lang.IllegalArgumentException: Invalid locale format: dd.MM.yyyy
	at org.apache.commons.lang3.LocaleUtils.parseLocale(LocaleUtils.java:294)
	at org.apache.commons.lang3.LocaleUtils.toLocale(LocaleUtils.java:376)
	at net.kaczmarzyk.spring.data.jpa.web.SimpleSpecificationResolver.resolveConverter(SimpleSpecificationResolver.java:157)
	at net.kaczmarzyk.spring.data.jpa.web.SimpleSpecificationResolver.newSpecification(SimpleSpecificationResolver.java:102)
	at net.kaczmarzyk.spring.data.jpa.web.SimpleSpecificationResolver.buildSpecification(SimpleSpecificationResolver.java:77)
	at net.kaczmarzyk.spring.data.jpa.web.SimpleSpecificationResolver.buildSpecification(SimpleSpecificationResolver.java:47)
	at net.kaczmarzyk.spring.data.jpa.web.SpecificationFactory.buildSpecification(SpecificationFactory.java:139)
	at net.kaczmarzyk.spring.data.jpa.web.SpecificationFactory.lambda$resolveSpecFromParameterAnnotations$1(SpecificationFactory.java:105)
	at net.kaczmarzyk.spring.data.jpa.web.SpecificationFactory.forEachSupportedSpecificationDefinition(SpecificationFactory.java:146)
	at net.kaczmarzyk.spring.data.jpa.web.SpecificationFactory.resolveSpecFromParameterAnnotations(SpecificationFactory.java:102)
	at net.kaczmarzyk.spring.data.jpa.web.SpecificationFactory.resolveSpec(SpecificationFactory.java:95)
	at net.kaczmarzyk.spring.data.jpa.web.SpecificationFactory.createSpecificationDependingOn(SpecificationFactory.java:76)
	at net.kaczmarzyk.spring.data.jpa.web.SpecificationArgumentResolver.resolveArgument(SpecificationArgumentResolver.java:105)
	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:122)
	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:230)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:180)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:934)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:853)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:86)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:866)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1003)
	... 9 more

specification-arg-resolver/src/main/java/net/kaczmarzyk/spring/data/jpa/web/SimpleSpecificationResolver.java

Lines 154 to 164 in 77bc7d0

	if (def.config().length == 1) {
	if (LocaleAware.class.isAssignableFrom(def.spec())) { // if specification is locale-aware, then we assume that config contains locale
	String localeConfig = def.config()[0];
	Locale customlocale = LocaleUtils.toLocale(localeConfig);
	return Converter.withTypeMismatchBehaviour(def.onTypeMismatch(), conversionService, customlocale);
	} else { // otherwise we assume that config contains date format
	String dateFormat = def.config()[0];
	return Converter.withDateFormat(dateFormat, def.onTypeMismatch(), conversionService);
	}
	}
	throw new IllegalStateException("config should contain only one value -- a date format"); // TODO support other config values as well

SimpleSpecificationResolver.resolveConverter always evaluates the config value as Locale for LocaleAware Specs. I'm unsure how this could be properly resolved. Maybe the config evaluation as Locale should move somewhere near CaseConversionHelper.applyCaseConversion, since it is only relevant when using IgnoreCaseStrategy.APPLICATION.

specification-arg-resolver/src/main/java/net/kaczmarzyk/spring/data/jpa/utils/CaseConversionHelper.java

Lines 48 to 76 in 77bc7d0

	if (effectiveStrategy == IgnoreCaseStrategy.APPLICATION) {
	Locale effectiveLocale = locale != null ? locale : Locale.getDefault();
	String convertedValue = value.toUpperCase(effectiveLocale);
	return new ConvertedExpressions(
	cb.upper(columnExpression),
	cb.literal(convertedValue)
	);
	}
	return new ConvertedExpressions(
	applyDatabaseCaseConversion(cb, columnExpression, effectiveStrategy),
	applyDatabaseCaseConversion(cb, cb.literal(value), effectiveStrategy)
	);
	}
	/**
	* Applies case conversion to both column expression and value according to the strategy.
	*/
	@SuppressWarnings("deprecation")
	public static ConvertedExpressionsList applyCaseConversion(
	CriteriaBuilder cb,
	Expression<String> columnExpression,
	String[] values,
	IgnoreCaseStrategy strategy,
	Locale locale) {
	IgnoreCaseStrategy effectiveStrategy = strategy != null ? strategy : IgnoreCaseStrategy.DATABASE_UPPER;
	if (effectiveStrategy == IgnoreCaseStrategy.APPLICATION) {

I added some test cases in my fork at cschierle@fab944b showcasing the IgnoreCase Specs supporting date fields running into this issue, while their exact match counterparts work just fine.

Any ideas how this issue could be resolved?

[cschierle]

Maybe an approach could be to evaluate the ignore case strategy

specification-arg-resolver/src/main/java/net/kaczmarzyk/spring/data/jpa/web/SimpleSpecificationResolver.java

Lines 129 to 131 in 77bc7d0

	if (spec instanceof IgnoreCaseStrategyAware && defaultIgnoreCaseStrategy != null) {
	((IgnoreCaseStrategyAware) spec).setIgnoreCaseStrategy(defaultIgnoreCaseStrategy);
	}

before or while the Converter is initialized

specification-arg-resolver/src/main/java/net/kaczmarzyk/spring/data/jpa/web/SimpleSpecificationResolver.java

Lines 98 to 105 in 77bc7d0

	private Specification<Object> newSpecification(Spec def, String[] argsArray, ProcessingContext context) throws InstantiationException, IllegalAccessException,
	InvocationTargetException, NoSuchMethodException {
	QueryContext queryCtx = context.queryContext();
	Converter converter = resolveConverter(def);
	Specification<Object> spec;
	if (def.config().length == 0) {

But I don't feel comfortable trying to implement that since possible dependencies are unclear to me