Add ability to customize ObjectMapper for HAL types.

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.hateoas</groupId>
 	<artifactId>spring-hateoas</artifactId>
-	<version>1.2.0-SNAPSHOT</version>
+	<version>1.2.0-HATEOAS-1382-SNAPSHOT</version>
 
 	<name>Spring HATEOAS</name>
 	<url>https://github.com/spring-projects/spring-hateoas</url>

src/main/java/org/springframework/hateoas/mediatype/hal/HalConfiguration.java

@@ -18,13 +18,16 @@
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.function.Consumer;
 
 import org.springframework.hateoas.Link;
 import org.springframework.hateoas.LinkRelation;
 import org.springframework.util.AntPathMatcher;
 import org.springframework.util.Assert;
 import org.springframework.util.PathMatcher;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
+
 /**
  * HAL specific configuration.
  *
@@ -41,6 +44,7 @@ public class HalConfiguration {
 	 */
 	private final RenderSingleLinks renderSingleLinks;
 	private final Map<String, RenderSingleLinks> singleLinksPerPattern;
+	private final Consumer<ObjectMapper> objectMapperCustomizer;
 
 	/**
 	 * Configures whether the Jackson property naming strategy is applied to link relations and within {@code _embedded}
@@ -63,15 +67,18 @@ public HalConfiguration() {
 		this.singleLinksPerPattern = new LinkedHashMap<>();
 		this.applyPropertyNamingStrategy = true;
 		this.enforceEmbeddedCollections = true;
+		this.objectMapperCustomizer = objectMapper -> {}; // Default to no action.
 	}
 
 	private HalConfiguration(RenderSingleLinks renderSingleLinks, Map<String, RenderSingleLinks> singleLinksPerPattern,
-			boolean applyPropertyNamingStrategy, boolean enforceEmbeddedCollections) {
+			boolean applyPropertyNamingStrategy, boolean enforceEmbeddedCollections,
+			Consumer<ObjectMapper> objectMapperCustomizer) {
 
 		this.renderSingleLinks = renderSingleLinks;
 		this.singleLinksPerPattern = singleLinksPerPattern;
 		this.applyPropertyNamingStrategy = applyPropertyNamingStrategy;
 		this.enforceEmbeddedCollections = enforceEmbeddedCollections;
+		this.objectMapperCustomizer = objectMapperCustomizer;
 	}
 
 	/**
@@ -132,7 +139,7 @@ public HalConfiguration withRenderSingleLinks(RenderSingleLinks renderSingleLink
 
 		return this.renderSingleLinks == renderSingleLinks ? this
 				: new HalConfiguration(renderSingleLinks, this.singleLinksPerPattern, this.applyPropertyNamingStrategy,
-						this.enforceEmbeddedCollections);
+						this.enforceEmbeddedCollections, this.objectMapperCustomizer);
 	}
 
 	/**
@@ -145,7 +152,7 @@ private HalConfiguration withSingleLinksPerPattern(Map<String, RenderSingleLinks
 
 		return this.singleLinksPerPattern == singleLinksPerPattern ? this
 				: new HalConfiguration(this.renderSingleLinks, singleLinksPerPattern, this.applyPropertyNamingStrategy,
-						this.enforceEmbeddedCollections);
+						this.enforceEmbeddedCollections, this.objectMapperCustomizer);
 	}
 
 	/**
@@ -159,7 +166,7 @@ public HalConfiguration withApplyPropertyNamingStrategy(boolean applyPropertyNam
 
 		return this.applyPropertyNamingStrategy == applyPropertyNamingStrategy ? this
 				: new HalConfiguration(this.renderSingleLinks, this.singleLinksPerPattern, applyPropertyNamingStrategy,
-						this.enforceEmbeddedCollections);
+						this.enforceEmbeddedCollections, this.objectMapperCustomizer);
 	}
 
 	/**
@@ -173,7 +180,14 @@ public HalConfiguration withEnforceEmbeddedCollections(boolean enforceEmbeddedCo
 
 		return this.enforceEmbeddedCollections == enforceEmbeddedCollections ? this
 				: new HalConfiguration(this.renderSingleLinks, this.singleLinksPerPattern, this.applyPropertyNamingStrategy,
-						enforceEmbeddedCollections);
+						enforceEmbeddedCollections, this.objectMapperCustomizer);
+	}
+
+	public HalConfiguration withObjectMapperCustomizer(Consumer<ObjectMapper> objectMapperCustomizer) {
+
+		return this.objectMapperCustomizer == objectMapperCustomizer ? this
+				: new HalConfiguration(this.renderSingleLinks, this.singleLinksPerPattern, this.applyPropertyNamingStrategy,
+						this.enforceEmbeddedCollections, objectMapperCustomizer);
 	}
 
 	public RenderSingleLinks getRenderSingleLinks() {
@@ -188,6 +202,10 @@ public boolean isEnforceEmbeddedCollections() {
 		return this.enforceEmbeddedCollections;
 	}
 
+	public Consumer<ObjectMapper> getObjectMapperCustomizer() {
+		return this.objectMapperCustomizer;
+	}
+
 	/**
 	 * Configuration option how to render single links of a given {@link LinkRelation}.
 	 *

src/main/java/org/springframework/hateoas/mediatype/hal/HalMediaTypeConfiguration.java

@@ -79,11 +79,14 @@ public List<MediaType> getMediaTypes() {
 	@Override
 	public ObjectMapper configureObjectMapper(ObjectMapper mapper) {
 
+		HalConfiguration halConfiguration = this.halConfiguration.getIfAvailable(HalConfiguration::new);
+
 		mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
 		mapper.registerModule(new Jackson2HalModule());
 		mapper.setHandlerInstantiator(new Jackson2HalModule.HalHandlerInstantiator(relProvider,
-				curieProvider.getIfAvailable(() -> CurieProvider.NONE), resolver,
-				halConfiguration.getIfAvailable(HalConfiguration::new), beanFactory));
+				curieProvider.getIfAvailable(() -> CurieProvider.NONE), resolver, halConfiguration, beanFactory));
+
+		halConfiguration.getObjectMapperCustomizer().accept(mapper);
 
 		return mapper;
 	}

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

@@ -82,6 +82,8 @@ public ObjectMapper configureObjectMapper(ObjectMapper mapper) {
 		mapper.setHandlerInstantiator(new Jackson2HalFormsModule.HalFormsHandlerInstantiator(relProvider,
 				curieProvider.getIfAvailable(() -> CurieProvider.NONE), resolver, configuration, beanFactory));
 
+		configuration.getHalConfiguration().getObjectMapperCustomizer().accept(mapper);
+
 		return mapper;
 	}
 

src/test/java/org/springframework/hateoas/mediatype/hal/HalObjectMapperCustomizerTest.java

@@ -0,0 +1,68 @@
+package org.springframework.hateoas.mediatype.hal;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.*;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.hateoas.MappingTestUtils;
+import org.springframework.hateoas.config.EnableHypermediaSupport;
+import org.springframework.hateoas.support.WebMvcEmployeeController;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+import com.fasterxml.jackson.databind.SerializationFeature;
+
+/**
+ * @author Greg Turnquist
+ */
+@ExtendWith(SpringExtension.class)
+@WebAppConfiguration
+@ContextConfiguration
+public class HalObjectMapperCustomizerTest {
+
+	@Autowired WebApplicationContext context;
+
+	MockMvc mockMvc;
+
+	MappingTestUtils.ContextualMapper mapper = MappingTestUtils.createMapper(getClass());
+
+	@BeforeEach
+	void setUp() {
+
+		this.mockMvc = webAppContextSetup(this.context).build();
+		WebMvcEmployeeController.reset();
+	}
+
+	@Test // #1382
+	void objectMapperCustomizerShouldBeApplied() throws Exception {
+
+		String actualHalJson = this.mockMvc.perform(get("/employees/0")).andReturn().getResponse().getContentAsString();
+		String expectedHalJson = this.mapper.readFile("hal-custom.json");
+
+		assertThat(actualHalJson).isEqualTo(expectedHalJson);
+	}
+
+	@Configuration
+	@EnableWebMvc
+	@EnableHypermediaSupport(type = EnableHypermediaSupport.HypermediaType.HAL)
+	@Import(WebMvcEmployeeController.class)
+	static class TestConfig {
+
+		@Bean
+		HalConfiguration halConfiguration() {
+			return new HalConfiguration()
+					.withObjectMapperCustomizer(objectMapper -> objectMapper.configure(SerializationFeature.INDENT_OUTPUT, true));
+		}
+	}
+}

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

@@ -0,0 +1,70 @@
+package org.springframework.hateoas.mediatype.hal.forms;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
+import static org.springframework.test.web.servlet.setup.MockMvcBuilders.*;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.hateoas.MappingTestUtils;
+import org.springframework.hateoas.config.EnableHypermediaSupport;
+import org.springframework.hateoas.mediatype.hal.HalConfiguration;
+import org.springframework.hateoas.support.WebMvcEmployeeController;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+import com.fasterxml.jackson.databind.SerializationFeature;
+
+/**
+ * @author Greg Turnquist
+ */
+@ExtendWith(SpringExtension.class)
+@WebAppConfiguration
+@ContextConfiguration
+public class HalFormsObjectMapperCustomizerTest {
+
+	@Autowired WebApplicationContext context;
+
+	MockMvc mockMvc;
+
+	MappingTestUtils.ContextualMapper mapper = MappingTestUtils.createMapper(getClass());
+
+	@BeforeEach
+	void setUp() {
+
+		this.mockMvc = webAppContextSetup(this.context).build();
+		WebMvcEmployeeController.reset();
+	}
+
+	@Test // #1382
+	void objectMapperCustomizerShouldBeApplied() throws Exception {
+
+		String actualHalFormsJson = this.mockMvc.perform(get("/employees/0")).andReturn().getResponse()
+				.getContentAsString();
+		String expectedHalFormsJson = this.mapper.readFile("hal-forms-custom.json");
+
+		assertThat(actualHalFormsJson).isEqualTo(expectedHalFormsJson);
+	}
+
+	@Configuration
+	@EnableWebMvc
+	@EnableHypermediaSupport(type = EnableHypermediaSupport.HypermediaType.HAL_FORMS)
+	@Import(WebMvcEmployeeController.class)
+	static class TestConfig {
+
+		@Bean
+		HalConfiguration halConfiguration() {
+			return new HalConfiguration()
+					.withObjectMapperCustomizer(objectMapper -> objectMapper.configure(SerializationFeature.INDENT_OUTPUT, true));
+		}
+	}
+}

src/test/resources/org/springframework/hateoas/mediatype/hal/forms/hal-forms-custom.json

@@ -0,0 +1,31 @@
+{
+  "name" : "Frodo Baggins",
+  "role" : "ring bearer",
+  "_links" : {
+    "self" : {
+      "href" : "http://localhost/employees/0"
+    },
+    "employees" : {
+      "href" : "http://localhost/employees"
+    }
+  },
+  "_templates" : {
+    "default" : {
+      "method" : "put",
+      "properties" : [ {
+        "name" : "name",
+        "required" : true
+      }, {
+        "name" : "role"
+      } ]
+    },
+    "partiallyUpdateEmployee" : {
+      "method" : "patch",
+      "properties" : [ {
+        "name" : "name"
+      }, {
+        "name" : "role"
+      } ]
+    }
+  }
+}

src/test/resources/org/springframework/hateoas/mediatype/hal/hal-custom.json

@@ -0,0 +1,12 @@
+{
+  "name" : "Frodo Baggins",
+  "role" : "ring bearer",
+  "_links" : {
+    "self" : {
+      "href" : "http://localhost/employees/0"
+    },
+    "employees" : {
+      "href" : "http://localhost/employees"
+    }
+  }
+}