Merge branch '2.4.x'

Closes gh-26585

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/ConfigDataEnvironment.java

@@ -233,7 +233,8 @@ class ConfigDataEnvironment {
 		contributors = processWithoutProfiles(contributors, importer, activationContext);
 		activationContext = withProfiles(contributors, activationContext);
 		contributors = processWithProfiles(contributors, importer, activationContext);
-		applyToEnvironment(contributors, activationContext, importer.getLoadedLocations());
+		applyToEnvironment(contributors, activationContext, importer.getLoadedLocations(),
+				importer.getOptionalLocations());
 	}
 
 	private ConfigDataEnvironmentContributors processInitial(ConfigDataEnvironmentContributors contributors,
@@ -322,9 +323,10 @@ class ConfigDataEnvironment {
 	}
 
 	private void applyToEnvironment(ConfigDataEnvironmentContributors contributors,
-			ConfigDataActivationContext activationContext, Set<ConfigDataLocation> loadedLocations) {
+			ConfigDataActivationContext activationContext, Set<ConfigDataLocation> loadedLocations,
+			Set<ConfigDataLocation> optionalLocations) {
 		checkForInvalidProperties(contributors);
-		checkMandatoryLocations(contributors, activationContext, loadedLocations);
+		checkMandatoryLocations(contributors, activationContext, loadedLocations, optionalLocations);
 		MutablePropertySources propertySources = this.environment.getPropertySources();
 		this.logger.trace("Applying config data environment contributions");
 		for (ConfigDataEnvironmentContributor contributor : contributors) {
@@ -359,7 +361,8 @@ class ConfigDataEnvironment {
 	}
 
 	private void checkMandatoryLocations(ConfigDataEnvironmentContributors contributors,
-			ConfigDataActivationContext activationContext, Set<ConfigDataLocation> loadedLocations) {
+			ConfigDataActivationContext activationContext, Set<ConfigDataLocation> loadedLocations,
+			Set<ConfigDataLocation> optionalLocations) {
 		Set<ConfigDataLocation> mandatoryLocations = new LinkedHashSet<>();
 		for (ConfigDataEnvironmentContributor contributor : contributors) {
 			if (contributor.isActive(activationContext)) {
@@ -372,6 +375,7 @@ class ConfigDataEnvironment {
 			}
 		}
 		mandatoryLocations.removeAll(loadedLocations);
+		mandatoryLocations.removeAll(optionalLocations);
 		if (!mandatoryLocations.isEmpty()) {
 			for (ConfigDataLocation mandatoryLocation : mandatoryLocations) {
 				this.notFoundAction.handle(this.logger, new ConfigDataLocationNotFoundException(mandatoryLocation));

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/ConfigDataImporter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -51,6 +51,8 @@ class ConfigDataImporter {
 
 	private final Set<ConfigDataLocation> loadedLocations = new HashSet<>();
 
+	private final Set<ConfigDataLocation> optionalLocations = new HashSet<>();
+
 	/**
 	 * Create a new {@link ConfigDataImporter} instance.
 	 * @param logFactory the log factory
@@ -103,7 +105,7 @@ class ConfigDataImporter {
 			return this.resolvers.resolve(locationResolverContext, location, profiles);
 		}
 		catch (ConfigDataNotFoundException ex) {
-			handle(ex, location);
+			handle(ex, location, null);
 			return Collections.emptyList();
 		}
 	}
@@ -115,6 +117,9 @@ class ConfigDataImporter {
 			ConfigDataResolutionResult candidate = candidates.get(i);
 			ConfigDataLocation location = candidate.getLocation();
 			ConfigDataResource resource = candidate.getResource();
+			if (resource.isOptional()) {
+				this.optionalLocations.add(location);
+			}
 			if (this.loaded.contains(resource)) {
 				this.loadedLocations.add(location);
 			}
@@ -128,26 +133,33 @@ class ConfigDataImporter {
 					}
 				}
 				catch (ConfigDataNotFoundException ex) {
-					handle(ex, location);
+					handle(ex, location, resource);
 				}
 			}
 		}
 		return Collections.unmodifiableMap(result);
 	}
 
-	private void handle(ConfigDataNotFoundException ex, ConfigDataLocation location) {
+	private void handle(ConfigDataNotFoundException ex, ConfigDataLocation location, ConfigDataResource resource) {
 		if (ex instanceof ConfigDataResourceNotFoundException) {
 			ex = ((ConfigDataResourceNotFoundException) ex).withLocation(location);
 		}
-		getNotFoundAction(location).handle(this.logger, ex);
+		getNotFoundAction(location, resource).handle(this.logger, ex);
 	}
 
-	private ConfigDataNotFoundAction getNotFoundAction(ConfigDataLocation location) {
-		return (!location.isOptional()) ? this.notFoundAction : ConfigDataNotFoundAction.IGNORE;
+	private ConfigDataNotFoundAction getNotFoundAction(ConfigDataLocation location, ConfigDataResource resource) {
+		if (location.isOptional() || (resource != null && resource.isOptional())) {
+			return ConfigDataNotFoundAction.IGNORE;
+		}
+		return this.notFoundAction;
 	}
 
 	Set<ConfigDataLocation> getLoadedLocations() {
 		return this.loadedLocations;
 	}
 
+	Set<ConfigDataLocation> getOptionalLocations() {
+		return this.optionalLocations;
+	}
+
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/ConfigDataResource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -27,4 +27,26 @@ package org.springframework.boot.context.config;
  */
 public abstract class ConfigDataResource {
 
+	private final boolean optional;
+
+	/**
+	 * Create a new non-optional {@link ConfigDataResource} instance.
+	 */
+	public ConfigDataResource() {
+		this(false);
+	}
+
+	/**
+	 * Create a new {@link ConfigDataResource} instance.
+	 * @param optional if the resource is optional
+	 * @since 2.4.6
+	 */
+	protected ConfigDataResource(boolean optional) {
+		this.optional = optional;
+	}
+
+	boolean isOptional() {
+		return this.optional;
+	}
+
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/ConfigDataEnvironmentPostProcessorIntegrationTests.java

@@ -46,6 +46,7 @@ import org.springframework.boot.context.properties.bind.Binder;
 import org.springframework.boot.context.properties.source.ConfigurationProperty;
 import org.springframework.boot.context.properties.source.ConfigurationPropertyName;
 import org.springframework.boot.origin.Origin;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.env.ConfigurableEnvironment;
@@ -581,6 +582,12 @@ class ConfigDataEnvironmentPostProcessorIntegrationTests {
 						+ StringUtils.cleanPath(location.getAbsolutePath())));
 	}
 
+	@Test
+	void runWhenResolvedIsOptionalDoesNotThrowException() {
+		ApplicationContext context = this.application.run("--spring.config.location=test:optionalresult");
+		assertThat(context.getEnvironment().containsProperty("spring")).isFalse();
+	}
+
 	@Test
 	@Disabled("Disabled until spring.profiles suppport is dropped")
 	void runWhenUsingInvalidPropertyThrowsException() {
@@ -752,4 +759,44 @@ class ConfigDataEnvironmentPostProcessorIntegrationTests {
 
 	}
 
+	static class LocationResolver implements ConfigDataLocationResolver<TestConfigDataResource> {
+
+		@Override
+		public boolean isResolvable(ConfigDataLocationResolverContext context, ConfigDataLocation location) {
+			return location.hasPrefix("test:");
+
+		}
+
+		@Override
+		public List<TestConfigDataResource> resolve(ConfigDataLocationResolverContext context,
+				ConfigDataLocation location)
+				throws ConfigDataLocationNotFoundException, ConfigDataResourceNotFoundException {
+			return Collections.singletonList(new TestConfigDataResource(location));
+		}
+
+	}
+
+	static class Loader implements ConfigDataLoader<TestConfigDataResource> {
+
+		@Override
+		public ConfigData load(ConfigDataLoaderContext context, TestConfigDataResource resource)
+				throws IOException, ConfigDataResourceNotFoundException {
+			if (resource.isOptional()) {
+				return null;
+			}
+			MapPropertySource propertySource = new MapPropertySource("loaded",
+					Collections.singletonMap("spring", "boot"));
+			return new ConfigData(Collections.singleton(propertySource));
+		}
+
+	}
+
+	static class TestConfigDataResource extends ConfigDataResource {
+
+		TestConfigDataResource(ConfigDataLocation location) {
+			super(location.toString().contains("optionalresult"));
+		}
+
+	}
+
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/ConfigDataLocationResolversTests.java

@@ -168,8 +168,27 @@ class ConfigDataLocationResolversTests {
 				.satisfies((ex) -> assertThat(ex.getLocation()).isEqualTo(location));
 	}
 
+	@Test
+	void resolveWhenOptional() {
+		ConfigDataLocationResolvers resolvers = new ConfigDataLocationResolvers(this.logFactory, this.bootstrapContext,
+				this.binder, this.resourceLoader, Arrays.asList(OptionalResourceTestResolver.class.getName()));
+		ConfigDataLocation location = ConfigDataLocation.of("OptionalResourceTestResolver:test");
+		List<ConfigDataResolutionResult> resolved = resolvers.resolve(this.context, location, null);
+		assertThat(resolved.get(0).getResource().isOptional()).isTrue();
+	}
+
 	static class TestResolver implements ConfigDataLocationResolver<TestConfigDataResource> {
 
+		private final boolean optionalResource;
+
+		TestResolver() {
+			this(false);
+		}
+
+		TestResolver(boolean optionalResource) {
+			this.optionalResource = optionalResource;
+		}
+
 		@Override
 		public boolean isResolvable(ConfigDataLocationResolverContext context, ConfigDataLocation location) {
 			String name = getClass().getName();
@@ -180,13 +199,13 @@ class ConfigDataLocationResolversTests {
 		@Override
 		public List<TestConfigDataResource> resolve(ConfigDataLocationResolverContext context,
 				ConfigDataLocation location) {
-			return Collections.singletonList(new TestConfigDataResource(this, location, false));
+			return Collections.singletonList(new TestConfigDataResource(this.optionalResource, this, location, false));
 		}
 
 		@Override
 		public List<TestConfigDataResource> resolveProfileSpecific(ConfigDataLocationResolverContext context,
 				ConfigDataLocation location, Profiles profiles) {
-			return Collections.singletonList(new TestConfigDataResource(this, location, true));
+			return Collections.singletonList(new TestConfigDataResource(this.optionalResource, this, location, true));
 		}
 
 	}
@@ -249,6 +268,14 @@ class ConfigDataLocationResolversTests {
 
 	}
 
+	static class OptionalResourceTestResolver extends TestResolver {
+
+		OptionalResourceTestResolver() {
+			super(true);
+		}
+
+	}
+
 	static class TestConfigDataResource extends ConfigDataResource {
 
 		private final TestResolver resolver;
@@ -257,7 +284,9 @@ class ConfigDataLocationResolversTests {
 
 		private final boolean profileSpecific;
 
-		TestConfigDataResource(TestResolver resolver, ConfigDataLocation location, boolean profileSpecific) {
+		TestConfigDataResource(boolean optional, TestResolver resolver, ConfigDataLocation location,
+				boolean profileSpecific) {
+			super(optional);
 			this.resolver = resolver;
 			this.location = location;
 			this.profileSpecific = profileSpecific;

spring-boot-project/spring-boot/src/test/resources/META-INF/spring.factories

@@ -3,9 +3,11 @@ org.springframework.boot.context.config.TestPropertySourceLoader1,\
 org.springframework.boot.context.config.TestPropertySourceLoader2
 
 org.springframework.boot.context.config.ConfigDataLocationResolver=\
+org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessorIntegrationTests.LocationResolver,\
 org.springframework.boot.context.config.TestConfigDataBootstrap.LocationResolver,\
 org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessorImportCombinedWithProfileSpecificIntegrationTests.LocationResolver
 
 org.springframework.boot.context.config.ConfigDataLoader=\
+org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessorIntegrationTests.Loader,\
 org.springframework.boot.context.config.TestConfigDataBootstrap.Loader,\
 org.springframework.boot.context.config.ConfigDataEnvironmentPostProcessorImportCombinedWithProfileSpecificIntegrationTests.Loader