Use LinkedHashMap and LinkedHashSet in configuration properties

buildSrc/src/main/java/org/springframework/boot/build/architecture/ArchitectureRules.java

@@ -77,6 +77,7 @@
  * @author Ngoc Nhan
  * @author Moritz Halbritter
  * @author Stefano Cordio
+ * @author Venkata Naga Sai Srikanth Gollapudi
  */
 final class ArchitectureRules {
 
@@ -126,7 +127,8 @@ static List<ArchRule> conditionalOnMissingBean(String annotationClass) {
 
 	static List<ArchRule> configurationProperties(String annotationClass) {
 		return List.of(classLevelConfigurationPropertiesShouldNotSpecifyOnlyPrefixAttribute(annotationClass),
-				methodLevelConfigurationPropertiesShouldNotSpecifyOnlyPrefixAttribute(annotationClass));
+				methodLevelConfigurationPropertiesShouldNotSpecifyOnlyPrefixAttribute(annotationClass),
+				configurationPropertiesShouldNotUseHashMapOrHashSet(annotationClass));
 	}
 
 	static List<ArchRule> configurationPropertiesBinding(String annotationClass) {
@@ -428,6 +430,36 @@ private static ArchRule allDeprecatedConfigurationPropertiesShouldIncludeSince(S
 			.allowEmptyShould(true);
 	}
 
+	private static ArchRule configurationPropertiesShouldNotUseHashMapOrHashSet(String annotationClass) {
+		DescribedPredicate<JavaCall<?>> hashMapOrHashSetConstructor = hasJavaCallTarget(
+				new DescribedPredicate<CodeUnitCallTarget>("is a HashMap or HashSet constructor") {
+					@Override
+					public boolean test(CodeUnitCallTarget target) {
+						String ownerName = target.getOwner().getName();
+						return ("java.util.HashMap".equals(ownerName) || "java.util.HashSet".equals(ownerName))
+								&& "<init>".equals(target.getName());
+					}
+				});
+		return ArchRuleDefinition.noClasses()
+			.that()
+			.areAnnotatedWith(annotationClass)
+			.or(areNestedInConfigurationPropertiesClasses(annotationClass))
+			.should()
+			.callConstructorWhere(hashMapOrHashSetConstructor)
+			.because("@ConfigurationProperties classes should use LinkedHashMap/LinkedHashSet "
+					+ "instead of HashMap/HashSet to preserve insertion order consistent with the Binder")
+
+			.allowEmptyShould(true);
+	}
+
+	private static DescribedPredicate<JavaClass> areNestedInConfigurationPropertiesClasses(String annotationClass) {
+		return DescribedPredicate.describe("are nested in @ConfigurationProperties",
+				(javaClass) -> javaClass.getEnclosingClass()
+					.map((enclosing) -> enclosing.isAnnotatedWith(annotationClass)
+							|| areNestedInConfigurationPropertiesClasses(annotationClass).test(enclosing))
+					.orElse(false));
+	}
+
 	private static ArchRule autoConfigurationClassesShouldBePublicAndFinal() {
 		return ArchRuleDefinition.classes()
 			.that(areRegularAutoConfiguration())

buildSrc/src/test/java/org/springframework/boot/build/architecture/ArchitectureCheckTests.java

@@ -62,6 +62,7 @@
  * @author Ivan Malutin
  * @author Dmytro Nosan
  * @author Stefano Cordio
+ * @author Venkata Naga Sai Srikanth Gollapudi
  */
 class ArchitectureCheckTests {
 
@@ -331,6 +332,34 @@ void whenMethodLevelConfigurationPropertiesContainsOnlyValueShouldSucceedAndWrit
 				Task.CHECK_ARCHITECTURE_MAIN);
 	}
 
+	@Test
+	void whenConfigurationPropertiesUsesHashMapShouldFailAndWriteReport() throws IOException {
+		prepareTask(Task.CHECK_ARCHITECTURE_MAIN, "configurationproperties/hashmap", "annotations");
+		buildAndFail(this.gradleBuild.withDependencies(SPRING_CONTEXT).withConfigurationPropertiesAnnotation(),
+				Task.CHECK_ARCHITECTURE_MAIN, "should use LinkedHashMap/LinkedHashSet instead of HashMap/HashSet");
+	}
+
+	@Test
+	void whenConfigurationPropertiesUsesHashSetShouldFailAndWriteReport() throws IOException {
+		prepareTask(Task.CHECK_ARCHITECTURE_MAIN, "configurationproperties/hashset", "annotations");
+		buildAndFail(this.gradleBuild.withDependencies(SPRING_CONTEXT).withConfigurationPropertiesAnnotation(),
+				Task.CHECK_ARCHITECTURE_MAIN, "should use LinkedHashMap/LinkedHashSet instead of HashMap/HashSet");
+	}
+
+	@Test
+	void whenConfigurationPropertiesUsesLinkedHashMapShouldSucceedAndWriteEmptyReport() throws IOException {
+		prepareTask(Task.CHECK_ARCHITECTURE_MAIN, "configurationproperties/linkedhashmap", "annotations");
+		build(this.gradleBuild.withDependencies(SPRING_CONTEXT).withConfigurationPropertiesAnnotation(),
+				Task.CHECK_ARCHITECTURE_MAIN);
+	}
+
+	@Test
+	void whenConfigurationPropertiesUsesLinkedHashSetShouldSucceedAndWriteEmptyReport() throws IOException {
+		prepareTask(Task.CHECK_ARCHITECTURE_MAIN, "configurationproperties/linkedhashset", "annotations");
+		build(this.gradleBuild.withDependencies(SPRING_CONTEXT).withConfigurationPropertiesAnnotation(),
+				Task.CHECK_ARCHITECTURE_MAIN);
+	}
+
 	@Test
 	void whenConfigurationPropertiesBindingBeanMethodIsNotStaticShouldFailAndWriteReport() throws IOException {
 		prepareTask(Task.CHECK_ARCHITECTURE_MAIN, "configurationproperties/bindingnonstatic", "annotations");

buildSrc/src/test/java/org/springframework/boot/build/architecture/configurationproperties/hashmap/ConfigurationPropertiesWithHashMap.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2012-present 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.boot.build.architecture.configurationproperties.hashmap;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.boot.build.architecture.annotations.TestConfigurationProperties;
+
+/**
+ * Test {@link TestConfigurationProperties} using {@link HashMap}.
+ *
+ * @author Venkata Naga Sai Srikanth Gollapudi
+ */
+@TestConfigurationProperties("testing")
+public class ConfigurationPropertiesWithHashMap {
+
+	private Map<String, String> properties = new HashMap<>();
+
+	public Map<String, String> getProperties() {
+		return this.properties;
+	}
+
+	public void setProperties(Map<String, String> properties) {
+		this.properties = properties;
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/configurationproperties/hashset/ConfigurationPropertiesWithHashSet.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2012-present 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.boot.build.architecture.configurationproperties.hashset;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.springframework.boot.build.architecture.annotations.TestConfigurationProperties;
+
+/**
+ * Test {@link TestConfigurationProperties} using {@link HashSet}.
+ *
+ * @author Venkata Naga Sai Srikanth Gollapudi
+ */
+@TestConfigurationProperties("testing")
+public class ConfigurationPropertiesWithHashSet {
+
+	private Set<String> items = new HashSet<>();
+
+	public Set<String> getItems() {
+		return this.items;
+	}
+
+	public void setItems(Set<String> items) {
+		this.items = items;
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/configurationproperties/linkedhashmap/ConfigurationPropertiesWithLinkedHashMap.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2012-present 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.boot.build.architecture.configurationproperties.linkedhashmap;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.springframework.boot.build.architecture.annotations.TestConfigurationProperties;
+
+/**
+ * Test {@link TestConfigurationProperties} using {@link LinkedHashMap}.
+ *
+ * @author Venkata Naga Sai Srikanth Gollapudi
+ */
+@TestConfigurationProperties("testing")
+public class ConfigurationPropertiesWithLinkedHashMap {
+
+	private Map<String, String> properties = new LinkedHashMap<>();
+
+	public Map<String, String> getProperties() {
+		return this.properties;
+	}
+
+	public void setProperties(Map<String, String> properties) {
+		this.properties = properties;
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/configurationproperties/linkedhashset/ConfigurationPropertiesWithLinkedHashSet.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2012-present 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.boot.build.architecture.configurationproperties.linkedhashset;
+
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import org.springframework.boot.build.architecture.annotations.TestConfigurationProperties;
+
+/**
+ * Test {@link TestConfigurationProperties} using {@link LinkedHashSet}.
+ *
+ * @author Venkata Naga Sai Srikanth Gollapudi
+ */
+@TestConfigurationProperties("testing")
+public class ConfigurationPropertiesWithLinkedHashSet {
+
+	private Set<String> items = new LinkedHashSet<>();
+
+	public Set<String> getItems() {
+		return this.items;
+	}
+
+	public void setItems(Set<String> items) {
+		this.items = items;
+	}
+
+}

documentation/spring-boot-docs/src/main/java/org/springframework/boot/docs/features/externalconfig/typesafeconfigurationproperties/relaxedbinding/mapsfromenvironmentvariables/MyMapsProperties.java

@@ -16,15 +16,15 @@
 
 package org.springframework.boot.docs.features.externalconfig.typesafeconfigurationproperties.relaxedbinding.mapsfromenvironmentvariables;
 
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 @ConfigurationProperties("my.props")
 public class MyMapsProperties {
 
-	private final Map<String, String> values = new HashMap<>();
+	private final Map<String, String> values = new LinkedHashMap<>();
 
 	public Map<String, String> getValues() {
 		return this.values;

documentation/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/features/externalconfig/typesafeconfigurationproperties/relaxedbinding/mapsfromenvironmentvariables/MyMapsProperties.kt

@@ -21,7 +21,7 @@ import org.springframework.boot.context.properties.ConfigurationProperties
 @ConfigurationProperties("my.props")
 class MyMapsProperties {
 
-	val values: Map<String, String> = HashMap()
+	val values: Map<String, String> = LinkedHashMap()
 
 }
 

module/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/context/properties/ConfigurationPropertiesReportEndpointProperties.java

@@ -16,7 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.context.properties;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.springframework.boot.actuate.context.properties.ConfigurationPropertiesReportEndpoint;
@@ -28,6 +28,7 @@
  *
  * @author Stephane Nicoll
  * @author Madhura Bhave
+ * @author Venkata Naga Sai Srikanth Gollapudi
  * @since 2.0.0
  */
 @ConfigurationProperties("management.endpoint.configprops")
@@ -42,7 +43,7 @@ public class ConfigurationPropertiesReportEndpointProperties {
 	 * Roles used to determine whether a user is authorized to be shown unsanitized
 	 * values. When empty, all authenticated users are authorized.
 	 */
-	private final Set<String> roles = new HashSet<>();
+	private final Set<String> roles = new LinkedHashSet<>();
 
 	public Show getShowValues() {
 		return this.showValues;

module/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/env/EnvironmentEndpointProperties.java

@@ -16,7 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.env;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.springframework.boot.actuate.endpoint.Show;
@@ -27,6 +27,7 @@
  * Configuration properties for {@link EnvironmentEndpoint}.
  *
  * @author Stephane Nicoll
+ * @author Venkata Naga Sai Srikanth Gollapudi
  * @since 2.0.0
  */
 @ConfigurationProperties("management.endpoint.env")
@@ -41,7 +42,7 @@ public class EnvironmentEndpointProperties {
 	 * Roles used to determine whether a user is authorized to be shown unsanitized
 	 * values. When empty, all authenticated users are authorized.
 	 */
-	private final Set<String> roles = new HashSet<>();
+	private final Set<String> roles = new LinkedHashSet<>();
 
 	public Show getShowValues() {
 		return this.showValues;

module/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/web/exchanges/HttpExchangesProperties.java

@@ -16,7 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.web.exchanges;
 
-import java.util.HashSet;
+import java.util.LinkedHashSet;
 import java.util.Set;
 
 import org.springframework.boot.actuate.web.exchanges.Include;
@@ -30,6 +30,7 @@
  * @author Venil Noronha
  * @author Madhura Bhave
  * @author Stephane Nicoll
+ * @author Venkata Naga Sai Srikanth Gollapudi
  * @since 2.0.0
  */
 @ConfigurationProperties("management.httpexchanges")
@@ -53,7 +54,7 @@ public static class Recording {
 		 * (excluding Authorization and Cookie), response headers (excluding Set-Cookie),
 		 * and time taken.
 		 */
-		private Set<Include> include = new HashSet<>(Include.defaultIncludes());
+		private Set<Include> include = new LinkedHashSet<>(Include.defaultIncludes());
 
 		public Set<Include> getInclude() {
 			return this.include;