#1003 - BoundMethodParameter now only uses first level nesting for JDK 8 optional.

Author: odrotbohm

src/main/java/org/springframework/hateoas/server/core/WebHandler.java

@@ -32,6 +32,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.function.BiFunction;
 import java.util.function.Function;
 
@@ -370,10 +371,12 @@ public BoundMethodParameter(MethodParameter parameter, @Nullable Object value, A
 
 				Assert.notNull(parameter, "MethodParameter must not be null!");
 
+				boolean isOptionalWrapper = Optional.class.isAssignableFrom(parameter.getParameterType());
+
 				this.parameter = parameter;
 				this.value = value;
 				this.attribute = attribute;
-				this.parameterTypeDescriptor = TypeDescriptor.nested(parameter, parameter.isOptional() ? 1 : 0);
+				this.parameterTypeDescriptor = TypeDescriptor.nested(parameter, isOptionalWrapper ? 1 : 0);
 			}
 
 			/**

src/test/java/org/springframework/hateoas/server/mvc/WebMvcLinkBuilderUnitTest.java

@@ -521,7 +521,8 @@ void addsOptionalRequestParameterTemplateForMissingValue() {
 
 		Link link = linkTo(methodOn(ControllerWithMethods.class).methodForNextPage("1", null, 5)).withSelfRel();
 
-		assertThat(link.getVariables()).containsExactly(new TemplateVariable("offset", VariableType.REQUEST_PARAM_CONTINUED));
+		assertThat(link.getVariables())
+				.containsExactly(new TemplateVariable("offset", VariableType.REQUEST_PARAM_CONTINUED));
 
 		UriComponents components = toComponents(link);
 
@@ -601,6 +602,18 @@ void alternativePathVariableParameter() {
 		assertThat(link.getHref()).isEqualTo("http://localhost/something/bar/foo");
 	}
 
+	/**
+	 * @see #1003, #122, #169
+	 */
+	@Test
+	void appendsOptionalParameterIfSet() {
+
+		Link link = linkTo(methodOn(ControllerWithMethods.class).methodForOptionalNextPage(1)).withSelfRel();
+
+		assertThat(link.getVariables()).isEmpty();
+		assertThat(link.expand().getHref()).endsWith("/foo?offset=1");
+	}
+
 	private static UriComponents toComponents(Link link) {
 		return UriComponentsBuilder.fromUriString(link.expand().getHref()).build();
 	}