#1557 - Add support for @DecimalMin and @DecimalMax.

Add support for decimal-based type validation constraints.

src/main/asciidoc/mediatypes.adoc

@@ -342,9 +342,9 @@ Each property will get the following attributes defined:
 |`readOnly`| Set to `true` if there's no setter method for the property. If that is present, use Jackson's `@JsonProperty(Access.READ_ONLY)` on the accessors or field explicitly. Not rendered by default, thus defaulting to `false`.
 |`regex`| Can be customized by using JSR-303's `@Pattern` annotation either on the field or a type. In case of the latter the pattern will be used for every property declared as that particular type. Not rendered by default.
 |`required`| Can be customized by using JSR-303's `@NotNull`. Not rendered by default and thus defaulting to `false`. Templates using `PATCH` as method will automatically have all properties set to not required.
-|`max`| The maximum value allowed for the property. Derived from Hibernate Validator's `@Range` or JSR-303's `@Max` annotations.
+|`max`| The maximum value allowed for the property. Derived from Hibernate Validator's `@Range` or JSR-303's `@Max` and `@DecimalMax` annotations.
 |`maxLength`| The maximum length value allowed for the property. Derived from Hibernate Validator's `@Length` annotation.
-|`min`| The minimum value allowed for the property. Derived from Hibernate Validator's `@Range` or JSR-303's `@Min` annotations.
+|`min`| The minimum value allowed for the property. Derived from Hibernate Validator's `@Range` or JSR-303's `@Min` and `@DecimalMin` annotations.
 |`minLength`| The minimum length value allowed for the property. Derived from Hibernate Validator's `@Length` annotation.
 |`options`| The options to select a value from when submitting the form. For details, see <<mediatypes.hal-forms.options>>.
 |`prompt`| The user readable prompt to use when rendering the form input. For details, see <<mediatypes.hal-forms.i18n.prompts>>. 

src/main/java/org/springframework/hateoas/AffordanceModel.java

@@ -468,7 +468,7 @@ public abstract class AffordanceModel {
 		 * @since 1.3
 		 */
 		@Nullable
-		default Long getMin() {
+		default Number getMin() {
 			return null;
 		}
 
@@ -479,7 +479,7 @@ public abstract class AffordanceModel {
 		 * @since 1.3
 		 */
 		@Nullable
-		default Long getMax() {
+		default Number getMax() {
 			return null;
 		}
 

src/main/java/org/springframework/hateoas/mediatype/PropertyUtils.java

@@ -20,11 +20,14 @@ import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.math.BigDecimal;
 import java.util.*;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import javax.validation.constraints.DecimalMax;
+import javax.validation.constraints.DecimalMin;
 import javax.validation.constraints.Email;
 import javax.validation.constraints.Max;
 import javax.validation.constraints.Min;
@@ -616,7 +619,7 @@ public class PropertyUtils {
 		 */
 		@Nullable
 		@Override
-		public Long getMin() {
+		public Number getMin() {
 
 			if (RANGE_ANNOTATION != null) {
 
@@ -627,7 +630,19 @@ public class PropertyUtils {
 				}
 			}
 
-			return getAnnotationAttribute(Min.class, "value", Long.class).orElse(null);
+			Optional<Long> minLong = getAnnotationAttribute(Min.class, "value", Long.class);
+
+			if (minLong.isPresent()) {
+				return minLong.get();
+			}
+
+			Optional<String> minDecimal = getAnnotationAttribute(DecimalMin.class, "value", String.class);
+
+			if (minDecimal.isPresent()) {
+				return new BigDecimal(minDecimal.get());
+			}
+
+			return null;
 		}
 
 		/*
@@ -636,7 +651,7 @@ public class PropertyUtils {
 		 */
 		@Nullable
 		@Override
-		public Long getMax() {
+		public Number getMax() {
 
 			if (RANGE_ANNOTATION != null) {
 
@@ -647,7 +662,19 @@ public class PropertyUtils {
 				}
 			}
 
-			return getAnnotationAttribute(Max.class, "value", Long.class).orElse(null);
+			Optional<Long> maxLong = getAnnotationAttribute(Max.class, "value", Long.class);
+
+			if (maxLong.isPresent()) {
+				return maxLong.get();
+			}
+
+			Optional<String> maxDecimal = getAnnotationAttribute(DecimalMax.class, "value", String.class);
+
+			if (maxDecimal.isPresent()) {
+				return new BigDecimal(maxDecimal.get());
+			}
+
+			return null;
 		}
 
 		/*

src/main/java/org/springframework/hateoas/mediatype/hal/forms/HalFormsProperty.java

@@ -42,7 +42,8 @@ final class HalFormsProperty implements Named {
 	private final Object value;
 	private final boolean templated, multi;
 	private final @JsonInclude(Include.NON_DEFAULT) boolean readOnly, required;
-	private final @Nullable Long min, max, minLength, maxLength;
+	private final @Nullable Number min, max;
+	private final @Nullable Long minLength, maxLength;
 	private final @Nullable HtmlInputType type;
 	private final @Nullable HalFormsOptions options;
 
@@ -67,7 +68,7 @@ final class HalFormsProperty implements Named {
 
 	private HalFormsProperty(String name, boolean readOnly, @Nullable Object value, String prompt, String regex,
 			boolean templated,
-			boolean required, boolean multi, String placeholder, @Nullable Long min, @Nullable Long max,
+			boolean required, boolean multi, String placeholder, @Nullable Number min, @Nullable Number max,
 			@Nullable Long minLength, @Nullable Long maxLength, @Nullable HtmlInputType type,
 			@Nullable HalFormsOptions options) {
 
@@ -237,7 +238,7 @@ final class HalFormsProperty implements Named {
 	 * @param min can be {@literal null}
 	 * @return will never be {@literal null}.
 	 */
-	HalFormsProperty withMin(@Nullable Long min) {
+	HalFormsProperty withMin(@Nullable Number min) {
 
 		return Objects.equals(this.min, min) ? this
 				: new HalFormsProperty(this.name, this.readOnly, this.value, this.prompt, this.regex, this.templated,
@@ -251,7 +252,7 @@ final class HalFormsProperty implements Named {
 	 * @param max can be {@literal null}
 	 * @return will never be {@literal null}.
 	 */
-	HalFormsProperty withMax(@Nullable Long max) {
+	HalFormsProperty withMax(@Nullable Number max) {
 
 		return Objects.equals(this.max, max) ? this
 				: new HalFormsProperty(this.name, this.readOnly, this.value, this.prompt, this.regex, this.templated,
@@ -375,7 +376,7 @@ final class HalFormsProperty implements Named {
 	 */
 	@Nullable
 	@JsonProperty
-	public Long getMin() {
+	public Number getMin() {
 		return min;
 	}
 
@@ -384,7 +385,7 @@ final class HalFormsProperty implements Named {
 	 */
 	@Nullable
 	@JsonProperty
-	public Long getMax() {
+	public Number getMax() {
 		return max;
 	}
 

src/test/java/org/springframework/hateoas/mediatype/hal/forms/HalFormsTemplateBuilderUnitTest.java

@@ -19,11 +19,14 @@ import static org.assertj.core.api.Assertions.*;
 
 import lombok.Getter;
 
+import java.math.BigDecimal;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
+import javax.validation.constraints.DecimalMax;
+import javax.validation.constraints.DecimalMin;
 import javax.validation.constraints.Max;
 import javax.validation.constraints.Min;
 import javax.validation.constraints.NotNull;
@@ -124,6 +127,22 @@ class HalFormsTemplateBuilderUnitTest {
 		assertThat(text).map(HalFormsProperty::getMaxLength).hasValue(5L);
 	}
 
+	@Test // #1557
+	void considersDecimalMinandDecimalMaxAnnotations() {
+
+		Link link = Affordances.of(Link.of("/example")) //
+				.afford(HttpMethod.POST) //
+				.withInput(Payload.class) //
+				.toLink();
+
+		HalFormsTemplate template = new HalFormsTemplateBuilder(new HalFormsConfiguration(), //
+				MessageResolver.DEFAULTS_ONLY).findTemplates(new RepresentationModel<>().add(link)).get("default");
+
+		Optional<HalFormsProperty> decimal = template.getPropertyByName("decimal");
+		assertThat(decimal).map(HalFormsProperty::getMin).hasValue(new BigDecimal("2.1"));
+		assertThat(decimal).map(HalFormsProperty::getMax).hasValue(new BigDecimal("5.3"));
+	}
+
 	@Test // #1427
 	void addsTargetAttributeForLinksNotPointingToSelf() {
 
@@ -238,5 +257,9 @@ class HalFormsTemplateBuilderUnitTest {
 
 		@Range(min = 8, max = 10) //
 		Integer range;
+
+		@DecimalMin("2.1") //
+		@DecimalMax("5.3") //
+		BigDecimal decimal;
 	}
 }