#467 - AnnotationMappingDiscoverer now considers @RequestMapping(params = …)

We now inspect the static request parameters declared in the actual request mapping and apply those values when building URIs pointing to those methods.

Original pull request: #1576.

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

@@ -15,6 +15,7 @@
  */
 package org.springframework.hateoas.server.core;
 
+import static java.util.Optional.ofNullable;
 import static org.springframework.core.annotation.AnnotatedElementUtils.*;
 import static org.springframework.core.annotation.AnnotationUtils.*;
 
@@ -40,6 +41,7 @@ import org.springframework.web.bind.annotation.RequestMethod;
  * @author Oliver Gierke
  * @author Mark Paluch
  * @author Greg Turnquist
+ * @author Réda Housni Alaoui
  * @deprecated since 1.2, not for removal but for hiding within the package in 1.3
  */
 @Deprecated
@@ -167,6 +169,14 @@ public class AnnotationMappingDiscoverer implements MappingDiscoverer {
 				: Arrays.stream(mediaTypes).map(MediaType::parseMediaType).collect(Collectors.toList());
 	}
 
+	@Override
+	public String[] getParams(Method method) {
+		Annotation annotation = findMergedAnnotation(method, annotationType);
+		String[] params = (String[]) getValue(annotation, "params");
+
+		return ofNullable(params).orElseGet(() -> new String[0]);
+	}
+
 	private String[] getMappingFrom(@Nullable Annotation annotation) {
 
 		if (annotation == null) {

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

@@ -31,6 +31,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Michal Stochmialek
  * @author Oliver Drotbohm
+ * @author Réda Housni Alaoui
  */
 public class CachingMappingDiscoverer implements MappingDiscoverer {
 
@@ -104,6 +105,11 @@ public class CachingMappingDiscoverer implements MappingDiscoverer {
 		return delegate.getConsumes(method);
 	}
 
+	@Override
+	public String[] getParams(Method method) {
+		return delegate.getParams(method);
+	}
+
 	private static String key(Class<?> type, @Nullable Method method) {
 
 		StringBuilder builder = new StringBuilder(type.getName());

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

@@ -29,6 +29,7 @@ import org.springframework.lang.Nullable;
  *
  * @author Oliver Gierke
  * @author Greg Turnquist
+ * @author Réda Housni Alaoui
  */
 public interface MappingDiscoverer {
 
@@ -79,4 +80,10 @@ public interface MappingDiscoverer {
 	 * @since 1.3
 	 */
 	List<MediaType> getConsumes(Method method);
+
+	/**
+	 * @param method - must not be null.
+	 * @return the parameters of the mapped request, narrowing the primary mapping.
+	 */
+	String[] getParams(Method method);
 }

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

@@ -31,6 +31,7 @@ import org.springframework.web.context.WebApplicationContext;
  *
  * @author Lars Michele
  * @author Oliver Drotbohm
+ * @author Réda Housni Alaoui
  */
 class PropertyResolvingMappingDiscoverer implements MappingDiscoverer {
 
@@ -91,6 +92,11 @@ class PropertyResolvingMappingDiscoverer implements MappingDiscoverer {
 		return delegate.getConsumes(method);
 	}
 
+	@Override
+	public String[] getParams(Method method) {
+		return delegate.getParams(method);
+	}
+
 	@Nullable
 	private static String resolveProperties(@Nullable String mapping) {
 

src/main/java/org/springframework/hateoas/server/mvc/WebMvcLinkBuilderFactory.java

@@ -24,9 +24,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
 import java.util.function.Supplier;
-
 import javax.servlet.ServletContext;
-
 import org.springframework.core.MethodParameter;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.format.support.DefaultFormattingConversionService;
@@ -34,12 +32,15 @@ import org.springframework.hateoas.Link;
 import org.springframework.hateoas.server.MethodLinkBuilderFactory;
 import org.springframework.hateoas.server.core.LinkBuilderSupport;
 import org.springframework.hateoas.server.core.MethodParameters;
+import org.springframework.hateoas.server.core.SpringAffordanceBuilder;
 import org.springframework.hateoas.server.core.WebHandler;
 import org.springframework.web.context.WebApplicationContext;
 import org.springframework.web.context.request.RequestAttributes;
 import org.springframework.web.context.request.RequestContextHolder;
 import org.springframework.web.context.request.ServletRequestAttributes;
 import org.springframework.web.context.support.WebApplicationContextUtils;
+import org.springframework.web.servlet.mvc.condition.NameValueExpression;
+import org.springframework.web.servlet.mvc.condition.ParamsRequestCondition;
 import org.springframework.web.util.UriComponentsBuilder;
 
 /**
@@ -54,6 +55,7 @@ import org.springframework.web.util.UriComponentsBuilder;
  * @author Kevin Conaway
  * @author Andrew Naydyonock
  * @author Greg Turnquist
+ * @author Réda Housni Alaoui
  */
 public class WebMvcLinkBuilderFactory implements MethodLinkBuilderFactory<WebMvcLinkBuilder> {
 
@@ -120,6 +122,19 @@ public class WebMvcLinkBuilderFactory implements MethodLinkBuilderFactory<WebMvc
 
 		return WebHandler.linkTo(invocationValue, WebMvcLinkBuilder::new, (builder, invocation) -> {
 
+			String[] primaryParams = SpringAffordanceBuilder.DISCOVERER.getParams(invocation.getMethod());
+			ParamsRequestCondition paramsRequestCondition = new ParamsRequestCondition(primaryParams);
+			for (NameValueExpression<String> expression: paramsRequestCondition.getExpressions()) {
+				if (expression.isNegated()) {
+					continue;
+				}
+				String value = expression.getValue();
+				if (value == null){
+					continue;
+				}
+				builder.queryParam(expression.getName(), value);
+			}
+
 			MethodParameters parameters = MethodParameters.of(invocation.getMethod());
 			Iterator<Object> parameterValues = Arrays.asList(invocation.getArguments()).iterator();
 

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

@@ -50,6 +50,7 @@ import org.springframework.web.util.UriComponentsBuilder;
  * @author Oliver Gierke
  * @author Kamill Sokol
  * @author Ross Turner
+ * @author Réda Housni Alaoui
  */
 class WebMvcLinkBuilderFactoryUnitTest extends TestUtils {
 
@@ -113,6 +114,13 @@ class WebMvcLinkBuilderFactoryUnitTest extends TestUtils {
 		assertThat(link.getHref()).endsWith("/something/with%20blank/foo");
 	}
 
+	@Test
+	void linksToMethodWithPrimaryParam(){
+		Link link = linkTo(methodOn(ControllerWithMethods.class).methodWithPrimaryParams()).withSelfRel();
+		assertThat(link.getRel()).isEqualTo(IanaLinkRelations.SELF);
+		assertThat(link.getHref()).endsWith("/something/foo?a=1&b=2");
+	}
+
 	/**
 	 * @see #96
 	 */

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

@@ -58,6 +58,7 @@ import org.springframework.web.util.UriComponentsBuilder;
  * @author Kevin Conaway
  * @author Oliver Trosien
  * @author Greg Turnquist
+ * @author Réda Housni Alaoui
  */
 class WebMvcLinkBuilderUnitTest extends TestUtils {
 
@@ -666,6 +667,11 @@ class WebMvcLinkBuilderUnitTest extends TestUtils {
 			return null;
 		}
 
+		@RequestMapping(path = "/foo", params = {"a=1", "b=2", "c!=4", "!d"})
+		HttpEntity<Void> methodWithPrimaryParams(){
+			return null;
+		}
+
 		@RequestMapping(value = "/{id}/foo")
 		HttpEntity<Void> methodForNextPage(@PathVariable String id, @RequestParam(required = false) Integer offset,
 				@RequestParam Integer limit) {