Property Resolving in @RequestMapping for Spring Boot

src/main/java/org/springframework/hateoas/config/EnvironmentConfiguration.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.hateoas.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.hateoas.server.core.EnvironmentContextFilter;
+
+@Configuration
+public class EnvironmentConfiguration {
+
+	@Bean
+	EnvironmentContextFilter environmentContextFilter() {
+		return new EnvironmentContextFilter();
+	}
+}

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

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.hateoas.server.core;
+
+import org.springframework.core.env.Environment;
+
+/**
+ * {@code EnvironmentContext} holds the {@link Environment} of the current servlet request provided by the
+ * {@link EnvironmentContextFilter}. The {@link Environment} is needed by the {@link PropertyResolvingMappingDiscoverer}
+ * to be able to resolve properties.
+ *
+ * @author Lars Michele
+ */
+class EnvironmentContext {
+
+	private static final ThreadLocal<Environment> ENVIRONMENT = new ThreadLocal<>();
+
+	static Environment get() {
+		return ENVIRONMENT.get();
+	}
+
+	static void set(Environment environment) {
+		ENVIRONMENT.set(environment);
+	}
+
+	static void clear() {
+		ENVIRONMENT.remove();
+	}
+}

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

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.hateoas.server.core;
+
+import javax.servlet.*;
+import java.io.IOException;
+
+import org.springframework.context.EnvironmentAware;
+import org.springframework.core.env.Environment;
+
+/**
+ * The {@code EnvironmentContextFilter} populates the {@link EnvironmentContext} with the {@link Environment} of the
+ * current servlet request.
+ *
+ * @author Lars Michele
+ */
+public class EnvironmentContextFilter implements Filter, EnvironmentAware {
+
+	private Environment environment;
+
+	@Override
+	public void init(FilterConfig filterConfig) {
+		// NOOP
+	}
+
+	@Override
+	public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
+			throws IOException, ServletException {
+		try {
+			EnvironmentContext.set(environment);
+			chain.doFilter(servletRequest, servletResponse);
+		} finally {
+			EnvironmentContext.clear();
+		}
+	}
+
+
+	@Override
+	public void destroy() {
+		// NOOP
+	}
+
+	@Override
+	public void setEnvironment(Environment environment) {
+		this.environment = environment;
+	}
+}

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

@@ -18,11 +18,10 @@
 import java.lang.reflect.Method;
 import java.util.Collection;
 
+import org.springframework.core.env.Environment;
 import org.springframework.http.HttpMethod;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
-import org.springframework.web.context.ContextLoader;
-import org.springframework.web.context.WebApplicationContext;
 
 /**
  * Property resolving adapter of {@link MappingDiscoverer}.
@@ -84,13 +83,13 @@ public Collection<HttpMethod> getRequestMethod(Class<?> type, Method method) {
 	private static String resolveProperties(@Nullable String mapping) {
 
 		if (mapping == null) {
-			return mapping;
+			return null;
 		}
 
-		WebApplicationContext context = ContextLoader.getCurrentWebApplicationContext();
+		Environment environment = EnvironmentContext.get();
 
-		return context == null //
+		return environment == null //
 				? mapping //
-				: context.getEnvironment().resolvePlaceholders(mapping);
+				: environment.resolvePlaceholders(mapping);
 	}
 }

src/test/java/org/springframework/hateoas/server/core/PropertyResolvingMappingDiscovererUnitTest.java

@@ -16,21 +16,21 @@
 package org.springframework.hateoas.server.core;
 
 import static org.assertj.core.api.Assertions.*;
+import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.*;
 
 import java.lang.reflect.Method;
 
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.hateoas.IanaLinkRelations;
+import org.springframework.hateoas.Link;
 import org.springframework.hateoas.TestUtils;
-import org.springframework.hateoas.server.core.AnnotationMappingDiscoverer;
-import org.springframework.hateoas.server.core.PropertyResolvingMappingDiscoverer;
-import org.springframework.mock.web.MockServletContext;
 import org.springframework.test.context.TestPropertySource;
 import org.springframework.test.context.junit.jupiter.web.SpringJUnitWebConfig;
 import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.context.ContextLoader;
 import org.springframework.web.context.WebApplicationContext;
 
 /**
@@ -40,14 +40,19 @@
  * @author Oliver Drotbohm
  */
 @SpringJUnitWebConfig(classes = PropertyResolvingMappingDiscovererUnitTest.Config.class)
-@TestPropertySource(properties = { "test.parent=resolvedparent", "test.child=resolvedchild" })
+@TestPropertySource(properties = {"test.parent=resolvedparent", "test.child=resolvedchild"})
 class PropertyResolvingMappingDiscovererUnitTest extends TestUtils {
 
 	@Autowired WebApplicationContext context;
 
 	@BeforeEach
-	void contextLoading() {
-		new ContextLoader(context).initWebApplicationContext(new MockServletContext());
+	void fakeRequestFiltering() {
+		EnvironmentContext.set(context.getEnvironment());
+	}
+
+	@AfterEach
+	void clearContext() {
+		EnvironmentContext.clear();
 	}
 
 	/**
@@ -74,14 +79,22 @@ void resolvesVariablesInMappings() throws NoSuchMethodException {
 				.isEqualTo("/resolvedparent/resolvedchild");
 	}
 
+	@Test
+	void resolvesVariablesInLinkToMethodOnController() {
+
+		Link link = linkTo(methodOn(ResolveMethodEndpointController.class).method()).withSelfRel();
+		assertThat(link.getRel()).isEqualTo(IanaLinkRelations.SELF);
+		assertThat(link.getHref()).endsWith("/resolvedparent/resolvedchild");
+	}
+
 	@RequestMapping("/${test.parent}")
 	interface ResolveEndpointController {}
 
 	@RequestMapping("/${test.parent}")
 	interface ResolveMethodEndpointController {
 
 		@RequestMapping("/${test.child}")
-		void method();
+		Object method();
 	}
 
 	@Configuration