fix(servlet): 修复转换器返回可空类型的问题

- 将 AnyEnumConverterFactory 中的转换器泛型改为允许返回可空类型
- 修改 AnyEnumConverter 内部转换器泛型为可空类型
- 更新 JavaLocalDateConverter 返回类型为可空 LocalDate
- 更新 JavaLocalDateTimeConverter 返回可空 LocalDateTime
- 更新 JavaLocalTimeConverter 返回可空 LocalTime

Author: TrueNine

depend/depend-servlet/src/main/kotlin/io/github/truenine/composeserver/depend/servlet/converters/AnyEnumConverterFactory.kt

@@ -10,7 +10,7 @@ import org.springframework.core.convert.converter.ConverterFactory
 @Deprecated(message = "API burden is too high", level = DeprecationLevel.ERROR)
 open class AnyEnumConverterFactory : ConverterFactory<String, IAnyEnum> {
   companion object {
-    @JvmStatic private val converters = ConcurrentHashMap<Class<*>, Converter<String, IAnyEnum>>()
+    @JvmStatic private val converters = ConcurrentHashMap<Class<*>, Converter<String, IAnyEnum?>>()
   }
 
   @Suppress("UNCHECKED_CAST")
@@ -24,7 +24,7 @@ open class AnyEnumConverterFactory : ConverterFactory<String, IAnyEnum> {
     } as Converter<String, T>
   }
 
-  private class AnyEnumConverter(targetClass: Class<out IAnyEnum?>) : Converter<String, IAnyEnum> {
+  private class AnyEnumConverter(targetClass: Class<out IAnyEnum?>) : Converter<String, IAnyEnum?> {
     private val isString = IStringEnum::class.java.isAssignableFrom(targetClass)
     private val isInt = IIntEnum::class.java.isAssignableFrom(targetClass)
     private val valueMappingMap = targetClass.enumConstants.associateBy { it?.value }

depend/depend-servlet/src/main/kotlin/io/github/truenine/composeserver/depend/servlet/converters/JavaLocalDateConverter.kt

@@ -7,7 +7,7 @@ import org.springframework.core.convert.converter.Converter
 
 private val log = slf4j(JavaLocalDateConverter::class)
 
-open class JavaLocalDateConverter : Converter<String, LocalDate> {
+open class JavaLocalDateConverter : Converter<String, LocalDate?> {
   override fun convert(source: String): LocalDate? {
     log.trace("Converting date = {}", source)
     return source.toLongOrNull()?.toLocalDate()

depend/depend-servlet/src/main/kotlin/io/github/truenine/composeserver/depend/servlet/converters/JavaLocalDateTimeConverter.kt

@@ -7,7 +7,7 @@ import org.springframework.core.convert.converter.Converter
 
 private val log = slf4j(JavaLocalDateTimeConverter::class)
 
-open class JavaLocalDateTimeConverter : Converter<String, LocalDateTime> {
+open class JavaLocalDateTimeConverter : Converter<String, LocalDateTime?> {
   override fun convert(source: String): LocalDateTime? {
     log.trace("Converting date-time = {}", source)
     return source.toLongOrNull()?.toLocalDateTime()

depend/depend-servlet/src/main/kotlin/io/github/truenine/composeserver/depend/servlet/converters/JavaLocalTimeConverter.kt

@@ -7,7 +7,7 @@ import org.springframework.core.convert.converter.Converter
 
 private val log = slf4j(JavaLocalTimeConverter::class)
 
-open class JavaLocalTimeConverter : Converter<String, LocalTime> {
+open class JavaLocalTimeConverter : Converter<String, LocalTime?> {
   override fun convert(source: String): LocalTime? {
     log.trace("Converting time = {}", source)
     return source.toLongOrNull()?.toLocalTime()