Allow placeholders to be used in imports

Allow `${..}` property placeholders to be used in `spring.config.import`
properties. Prior to this commit, placeholders were not resolved when
binding the `ConfigDataProperty` instance. Furthermore, binding happened
too early for all placeholders to be resolved correctly. The
`ConfigDataEnvironmentContributor` class now has two states for imported
contributors, `UNBOUND_IMPORT` has the initial unbound state and is
eventually replaced with a `BOUND_IMPORT`.

Closes gh-23020

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

@@ -235,7 +235,7 @@ class ConfigDataEnvironment {
 		MutablePropertySources propertySources = this.environment.getPropertySources();
 		this.logger.trace("Applying config data environment contributions");
 		for (ConfigDataEnvironmentContributor contributor : contributors) {
-			if (contributor.getKind() == ConfigDataEnvironmentContributor.Kind.IMPORTED
+			if (contributor.getKind() == ConfigDataEnvironmentContributor.Kind.BOUND_IMPORT
 					&& contributor.getPropertySource() != null) {
 				if (!contributor.isActive(activationContext)) {
 					this.logger.trace(LogMessage.format("Skipping inactive property source '%s'",

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

@@ -59,6 +59,8 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 
 	private final ConfigDataProperties properties;
 
+	private final boolean ignoreImports;
+
 	private final Map<ImportPhase, List<ConfigDataEnvironmentContributor>> children;
 
 	private final Kind kind;
@@ -71,16 +73,18 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 	 * @param configurationPropertySource the configuration property source for the data
 	 * or {@code null}
 	 * @param properties the config data properties or {@code null}
+	 * @param ignoreImports if import properties should be ignored
 	 * @param children the children of this contributor at each {@link ImportPhase}
 	 */
 	ConfigDataEnvironmentContributor(Kind kind, ConfigDataLocation location, PropertySource<?> propertySource,
 			ConfigurationPropertySource configurationPropertySource, ConfigDataProperties properties,
-			Map<ImportPhase, List<ConfigDataEnvironmentContributor>> children) {
+			boolean ignoreImports, Map<ImportPhase, List<ConfigDataEnvironmentContributor>> children) {
 		this.kind = kind;
 		this.location = location;
 		this.properties = properties;
 		this.propertySource = propertySource;
 		this.configurationPropertySource = configurationPropertySource;
+		this.ignoreImports = ignoreImports;
 		this.children = (children != null) ? children : Collections.emptyMap();
 	}
 
@@ -175,6 +179,16 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 		return new ContributorIterator();
 	}
 
+	ConfigDataEnvironmentContributor withBoundProperties(Binder binder) {
+		UseLegacyConfigProcessingException.throwIfRequested(binder);
+		ConfigDataProperties properties = ConfigDataProperties.get(binder);
+		if (this.ignoreImports) {
+			properties = properties.withoutImports();
+		}
+		return new ConfigDataEnvironmentContributor(Kind.BOUND_IMPORT, this.location, this.propertySource,
+				this.configurationPropertySource, properties, this.ignoreImports, null);
+	}
+
 	/**
 	 * Create a new {@link ConfigDataEnvironmentContributor} instance with a new set of
 	 * children for the given phase.
@@ -187,7 +201,7 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 		Map<ImportPhase, List<ConfigDataEnvironmentContributor>> updatedChildren = new LinkedHashMap<>(this.children);
 		updatedChildren.put(importPhase, children);
 		return new ConfigDataEnvironmentContributor(this.kind, this.location, this.propertySource,
-				this.configurationPropertySource, this.properties, updatedChildren);
+				this.configurationPropertySource, this.properties, this.ignoreImports, updatedChildren);
 	}
 
 	/**
@@ -212,7 +226,7 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 			updatedChildren.put(importPhase, Collections.unmodifiableList(updatedContributors));
 		});
 		return new ConfigDataEnvironmentContributor(this.kind, this.location, this.propertySource,
-				this.configurationPropertySource, this.properties, updatedChildren);
+				this.configurationPropertySource, this.properties, this.ignoreImports, updatedChildren);
 	}
 
 	/**
@@ -223,20 +237,20 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 	static ConfigDataEnvironmentContributor of(List<ConfigDataEnvironmentContributor> contributors) {
 		Map<ImportPhase, List<ConfigDataEnvironmentContributor>> children = new LinkedHashMap<>();
 		children.put(ImportPhase.BEFORE_PROFILE_ACTIVATION, Collections.unmodifiableList(contributors));
-		return new ConfigDataEnvironmentContributor(Kind.ROOT, null, null, null, null, children);
+		return new ConfigDataEnvironmentContributor(Kind.ROOT, null, null, null, null, false, children);
 	}
 
 	/**
 	 * Factory method to create a {@link Kind#INITIAL_IMPORT initial import} contributor.
 	 * This contributor is used to trigger initial imports of additional contributors. It
 	 * does not contribute any properties itself.
-	 * @param importLocation the initial import location
+	 * @param importLocation the initial import location (with placeholder resolved)
 	 * @return a new {@link ConfigDataEnvironmentContributor} instance
 	 */
 	static ConfigDataEnvironmentContributor ofInitialImport(String importLocation) {
 		List<String> imports = Collections.singletonList(importLocation);
 		ConfigDataProperties properties = new ConfigDataProperties(imports, null);
-		return new ConfigDataEnvironmentContributor(Kind.INITIAL_IMPORT, null, null, null, properties, null);
+		return new ConfigDataEnvironmentContributor(Kind.INITIAL_IMPORT, null, null, null, properties, false, null);
 	}
 
 	/**
@@ -248,31 +262,25 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 	 */
 	static ConfigDataEnvironmentContributor ofExisting(PropertySource<?> propertySource) {
 		return new ConfigDataEnvironmentContributor(Kind.EXISTING, null, propertySource,
-				ConfigurationPropertySource.from(propertySource), null, null);
+				ConfigurationPropertySource.from(propertySource), null, false, null);
 	}
 
 	/**
-	 * Factory method to create a {@link Kind#IMPORTED imported} contributor. This
+	 * Factory method to create an {@link Kind#UNBOUND_IMPORT unbound import} contributor.
-	 * contributor has been actively imported from another contributor and may itself
+	 * This contributor has been actively imported from another contributor and may itself
 	 * import further contributors later.
 	 * @param location the location of imported config data
 	 * @param configData the config data
 	 * @param propertySourceIndex the index of the property source that should be used
-	 * @param activationContext the current activation context
 	 * @return a new {@link ConfigDataEnvironmentContributor} instance
 	 */
-	static ConfigDataEnvironmentContributor ofImported(ConfigDataLocation location, ConfigData configData,
+	static ConfigDataEnvironmentContributor ofUnboundImport(ConfigDataLocation location, ConfigData configData,
-			int propertySourceIndex, ConfigDataActivationContext activationContext) {
+			int propertySourceIndex) {
 		PropertySource<?> propertySource = configData.getPropertySources().get(propertySourceIndex);
 		ConfigurationPropertySource configurationPropertySource = ConfigurationPropertySource.from(propertySource);
-		Binder binder = new Binder(configurationPropertySource);
+		boolean ignoreImports = configData.getOptions().contains(ConfigData.Option.IGNORE_IMPORTS);
-		UseLegacyConfigProcessingException.throwIfRequested(binder);
+		return new ConfigDataEnvironmentContributor(Kind.UNBOUND_IMPORT, location, propertySource,
-		ConfigDataProperties properties = ConfigDataProperties.get(binder);
+				configurationPropertySource, null, ignoreImports, null);
-		if (configData.getOptions().contains(ConfigData.Option.IGNORE_IMPORTS)) {
-			properties = properties.withoutImports();
-		}
-		return new ConfigDataEnvironmentContributor(Kind.IMPORTED, location, propertySource,
-				configurationPropertySource, properties, null);
 	}
 
 	/**
@@ -296,9 +304,16 @@ class ConfigDataEnvironmentContributor implements Iterable<ConfigDataEnvironment
 		EXISTING,
 
 		/**
-		 * A contributor with {@link ConfigData} imported from another contributor.
+		 * A contributor with {@link ConfigData} imported from another contributor but not
+		 * yet bound.
 		 */
-		IMPORTED;
+		UNBOUND_IMPORT,
+
+		/**
+		 * A contributor with {@link ConfigData} imported from another contributor that
+		 * has been.
+		 */
+		BOUND_IMPORT;
 
 	}
 

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

@@ -29,6 +29,7 @@ import java.util.stream.Stream;
 import org.apache.commons.logging.Log;
 
 import org.springframework.boot.context.config.ConfigDataEnvironmentContributor.ImportPhase;
+import org.springframework.boot.context.config.ConfigDataEnvironmentContributor.Kind;
 import org.springframework.boot.context.properties.bind.BindContext;
 import org.springframework.boot.context.properties.bind.BindHandler;
 import org.springframework.boot.context.properties.bind.Bindable;
@@ -91,27 +92,38 @@ class ConfigDataEnvironmentContributors implements Iterable<ConfigDataEnvironmen
 		this.logger.trace(LogMessage.format("Processing imports for phase %s. %s", importPhase,
 				(activationContext != null) ? activationContext : "no activation context"));
 		ConfigDataEnvironmentContributors result = this;
-		int processedCount = 0;
+		int processed = 0;
 		while (true) {
-			ConfigDataEnvironmentContributor unprocessed = getFirstUnprocessed(result, activationContext, importPhase);
+			ConfigDataEnvironmentContributor contributor = getNextToProcess(result, activationContext, importPhase);
-			if (unprocessed == null) {
+			if (contributor == null) {
-				this.logger.trace(LogMessage.format("Processed imports for of %d contributors", processedCount));
+				this.logger.trace(LogMessage.format("Processed imports for of %d contributors", processed));
 				return result;
 			}
+			if (contributor.getKind() == Kind.UNBOUND_IMPORT) {
+				Iterable<ConfigurationPropertySource> sources = Collections
+						.singleton(contributor.getConfigurationPropertySource());
+				PlaceholdersResolver placeholdersResolver = new ConfigDataEnvironmentContributorPlaceholdersResolver(
+						result, activationContext, true);
+				Binder binder = new Binder(sources, placeholdersResolver, null, null, null);
+				ConfigDataEnvironmentContributor bound = contributor.withBoundProperties(binder);
+				result = new ConfigDataEnvironmentContributors(this.logger, this.bootstrapRegistry,
+						result.getRoot().withReplacement(contributor, bound));
+				continue;
+			}
 			ConfigDataLocationResolverContext locationResolverContext = new ContributorConfigDataLocationResolverContext(
-					result, unprocessed, activationContext);
+					result, contributor, activationContext);
 			ConfigDataLoaderContext loaderContext = new ContributorDataLoaderContext(this);
-			List<String> imports = unprocessed.getImports();
+			List<String> imports = contributor.getImports();
 			this.logger.trace(LogMessage.format("Processing imports %s", imports));
 			Map<ConfigDataLocation, ConfigData> imported = importer.resolveAndLoad(activationContext,
 					locationResolverContext, loaderContext, imports);
 			this.logger.trace(LogMessage.of(() -> imported.isEmpty() ? "Nothing imported" : "Imported "
 					+ imported.size() + " location " + ((imported.size() != 1) ? "s" : "") + imported.keySet()));
-			ConfigDataEnvironmentContributor processed = unprocessed.withChildren(importPhase,
+			ConfigDataEnvironmentContributor contributorAndChildren = contributor.withChildren(importPhase,
-					asContributors(activationContext, imported));
+					asContributors(imported));
 			result = new ConfigDataEnvironmentContributors(this.logger, this.bootstrapRegistry,
-					result.getRoot().withReplacement(unprocessed, processed));
+					result.getRoot().withReplacement(contributor, contributorAndChildren));
-			processedCount++;
+			processed++;
 		}
 	}
 
@@ -119,22 +131,27 @@ class ConfigDataEnvironmentContributors implements Iterable<ConfigDataEnvironmen
 		return this.bootstrapRegistry;
 	}
 
-	private ConfigDataEnvironmentContributor getFirstUnprocessed(ConfigDataEnvironmentContributors contributors,
+	private ConfigDataEnvironmentContributor getNextToProcess(ConfigDataEnvironmentContributors contributors,
 			ConfigDataActivationContext activationContext, ImportPhase importPhase) {
 		for (ConfigDataEnvironmentContributor contributor : contributors.getRoot()) {
-			if (contributor.isActive(activationContext) && contributor.hasUnprocessedImports(importPhase)) {
+			if (contributor.getKind() == Kind.UNBOUND_IMPORT
+					|| isActiveWithUnprocessedImports(activationContext, importPhase, contributor)) {
 				return contributor;
 			}
 		}
 		return null;
 	}
 
-	private List<ConfigDataEnvironmentContributor> asContributors(ConfigDataActivationContext activationContext,
+	private boolean isActiveWithUnprocessedImports(ConfigDataActivationContext activationContext,
-			Map<ConfigDataLocation, ConfigData> imported) {
+			ImportPhase importPhase, ConfigDataEnvironmentContributor contributor) {
+		return contributor.isActive(activationContext) && contributor.hasUnprocessedImports(importPhase);
+	}
+
+	private List<ConfigDataEnvironmentContributor> asContributors(Map<ConfigDataLocation, ConfigData> imported) {
 		List<ConfigDataEnvironmentContributor> contributors = new ArrayList<>(imported.size() * 5);
 		imported.forEach((location, data) -> {
 			for (int i = data.getPropertySources().size() - 1; i >= 0; i--) {
-				contributors.add(ConfigDataEnvironmentContributor.ofImported(location, data, i, activationContext));
+				contributors.add(ConfigDataEnvironmentContributor.ofUnboundImport(location, data, i));
 			}
 		});
 		return Collections.unmodifiableList(contributors);
@@ -155,14 +172,18 @@ class ConfigDataEnvironmentContributors implements Iterable<ConfigDataEnvironmen
 	 * @return a binder instance
 	 */
 	Binder getBinder(ConfigDataActivationContext activationContext, BinderOption... options) {
-		return getBinder(activationContext, ObjectUtils.isEmpty(options) ? EnumSet.noneOf(BinderOption.class)
+		return getBinder(activationContext, asBinderOptionsSet(options));
-				: EnumSet.copyOf(Arrays.asList(options)));
+	}
+
+	private Set<BinderOption> asBinderOptionsSet(BinderOption... options) {
+		return ObjectUtils.isEmpty(options) ? EnumSet.noneOf(BinderOption.class)
+				: EnumSet.copyOf(Arrays.asList(options));
 	}
 
 	private Binder getBinder(ConfigDataActivationContext activationContext, Set<BinderOption> options) {
 		boolean failOnInactiveSource = options.contains(BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);
 		Iterable<ConfigurationPropertySource> sources = () -> getBinderSources(activationContext,
-				!failOnInactiveSource);
+				!options.contains(BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE));
 		PlaceholdersResolver placeholdersResolver = new ConfigDataEnvironmentContributorPlaceholdersResolver(this.root,
 				activationContext, failOnInactiveSource);
 		BindHandler bindHandler = !failOnInactiveSource ? null : new InactiveSourceChecker(activationContext);

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

@@ -122,7 +122,7 @@ class ConfigDataEnvironmentContributorPlaceholdersResolverTests {
 		private final boolean active;
 
 		protected TestConfigDataEnvironmentContributor(PropertySource<?> propertySource, boolean active) {
-			super(Kind.ROOT, null, propertySource, null, null, null);
+			super(Kind.ROOT, null, propertySource, null, null, false, null);
 			this.active = active;
 		}
 

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

@@ -28,6 +28,7 @@ import org.junit.jupiter.api.Test;
 import org.springframework.boot.cloud.CloudPlatform;
 import org.springframework.boot.context.config.ConfigDataEnvironmentContributor.ImportPhase;
 import org.springframework.boot.context.config.ConfigDataEnvironmentContributor.Kind;
+import org.springframework.boot.context.properties.bind.Binder;
 import org.springframework.boot.context.properties.source.ConfigurationPropertyName;
 import org.springframework.mock.env.MockPropertySource;
 
@@ -63,8 +64,7 @@ class ConfigDataEnvironmentContributorTests {
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring.config.activate.on-cloud-platform", "kubernetes");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		assertThat(contributor.isActive(this.activationContext)).isTrue();
 	}
 
@@ -73,8 +73,7 @@ class ConfigDataEnvironmentContributorTests {
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring.config.activate.on-cloud-platform", "heroku");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		assertThat(contributor.isActive(this.activationContext)).isFalse();
 	}
 
@@ -82,8 +81,8 @@ class ConfigDataEnvironmentContributorTests {
 	void getLocationReturnsLocation() {
 		ConfigData configData = new ConfigData(Collections.singleton(new MockPropertySource()));
 		ConfigDataLocation location = mock(ConfigDataLocation.class);
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(location, configData,
+		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofUnboundImport(location,
-				0, this.activationContext);
+				configData, 0);
 		assertThat(contributor.getLocation()).isSameAs(location);
 	}
 
@@ -99,8 +98,8 @@ class ConfigDataEnvironmentContributorTests {
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring", "boot");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofUnboundImport(null,
-				this.activationContext);
+				configData, 0);
 		assertThat(contributor.getConfigurationPropertySource()
 				.getConfigurationProperty(ConfigurationPropertyName.of("spring")).getValue()).isEqualTo("boot");
 	}
@@ -108,8 +107,7 @@ class ConfigDataEnvironmentContributorTests {
 	@Test
 	void getImportsWhenPropertiesIsNullReturnsEmptyList() {
 		ConfigData configData = new ConfigData(Collections.singleton(new MockPropertySource()));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		assertThat(contributor.getImports()).isEmpty();
 	}
 
@@ -118,16 +116,14 @@ class ConfigDataEnvironmentContributorTests {
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring.config.import", "spring,boot");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		assertThat(contributor.getImports()).containsExactly("spring", "boot");
 	}
 
 	@Test
 	void hasUnprocessedImportsWhenNoImportsReturnsFalse() {
 		ConfigData configData = new ConfigData(Collections.singleton(new MockPropertySource()));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		assertThat(contributor.hasUnprocessedImports(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isFalse();
 	}
 
@@ -136,8 +132,7 @@ class ConfigDataEnvironmentContributorTests {
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring.config.import", "springboot");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		assertThat(contributor.hasUnprocessedImports(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isTrue();
 	}
 
@@ -146,11 +141,9 @@ class ConfigDataEnvironmentContributorTests {
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring.config.import", "springboot");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		ConfigData childConfigData = new ConfigData(Collections.singleton(new MockPropertySource()));
-		ConfigDataEnvironmentContributor childContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor childContributor = createBoundContributor(null, childConfigData, 0);
-				childConfigData, 0, this.activationContext);
 		ConfigDataEnvironmentContributor withChildren = contributor.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION,
 				Collections.singletonList(childContributor));
 		assertThat(withChildren.hasUnprocessedImports(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isFalse();
@@ -160,8 +153,7 @@ class ConfigDataEnvironmentContributorTests {
 	@Test
 	void getChildrenWhenHasNoChildrenReturnsEmptyList() {
 		ConfigData configData = new ConfigData(Collections.singleton(new MockPropertySource()));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		assertThat(contributor.getChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isEmpty();
 		assertThat(contributor.getChildren(ImportPhase.AFTER_PROFILE_ACTIVATION)).isEmpty();
 	}
@@ -171,11 +163,9 @@ class ConfigDataEnvironmentContributorTests {
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring.config.import", "springboot");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(null, configData, 0,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(null, configData, 0);
-				this.activationContext);
 		ConfigData childConfigData = new ConfigData(Collections.singleton(new MockPropertySource()));
-		ConfigDataEnvironmentContributor childContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor childContributor = createBoundContributor(null, childConfigData, 0);
-				childConfigData, 0, this.activationContext);
 		ConfigDataEnvironmentContributor withChildren = contributor.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION,
 				Collections.singletonList(childContributor));
 		assertThat(withChildren.getChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION)).containsExactly(childContributor);
@@ -184,35 +174,36 @@ class ConfigDataEnvironmentContributorTests {
 
 	@Test
 	void streamReturnsStream() {
-		ConfigDataEnvironmentContributor contributor = createContributor("a");
+		ConfigDataEnvironmentContributor contributor = createBoundContributor("a");
 		Stream<String> stream = contributor.stream().map(this::getLocationName);
 		assertThat(stream).containsExactly("a");
 	}
 
 	@Test
 	void iteratorWhenSingleContributorReturnsSingletonIterator() {
-		ConfigDataEnvironmentContributor contributor = createContributor("a");
+		ConfigDataEnvironmentContributor contributor = createBoundContributor("a");
 		assertThat(asLocationsList(contributor.iterator())).containsExactly("a");
 	}
 
 	@Test
 	void iteratorWhenTypicalStructureReturnsCorrectlyOrderedIterator() {
-		ConfigDataEnvironmentContributor fileApplication = createContributor("file:application.properties");
+		ConfigDataEnvironmentContributor fileApplication = createBoundContributor("file:application.properties");
-		ConfigDataEnvironmentContributor fileProfile = createContributor("file:application-profile.properties");
+		ConfigDataEnvironmentContributor fileProfile = createBoundContributor("file:application-profile.properties");
-		ConfigDataEnvironmentContributor fileImports = createContributor("file:./");
+		ConfigDataEnvironmentContributor fileImports = createBoundContributor("file:./");
 		fileImports = fileImports.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION,
 				Collections.singletonList(fileApplication));
 		fileImports = fileImports.withChildren(ImportPhase.AFTER_PROFILE_ACTIVATION,
 				Collections.singletonList(fileProfile));
-		ConfigDataEnvironmentContributor classpathApplication = createContributor("classpath:application.properties");
+		ConfigDataEnvironmentContributor classpathApplication = createBoundContributor(
-		ConfigDataEnvironmentContributor classpathProfile = createContributor(
+				"classpath:application.properties");
+		ConfigDataEnvironmentContributor classpathProfile = createBoundContributor(
 				"classpath:application-profile.properties");
-		ConfigDataEnvironmentContributor classpathImports = createContributor("classpath:/");
+		ConfigDataEnvironmentContributor classpathImports = createBoundContributor("classpath:/");
 		classpathImports = classpathImports.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION,
 				Arrays.asList(classpathApplication));
 		classpathImports = classpathImports.withChildren(ImportPhase.AFTER_PROFILE_ACTIVATION,
 				Arrays.asList(classpathProfile));
-		ConfigDataEnvironmentContributor root = createContributor("root");
+		ConfigDataEnvironmentContributor root = createBoundContributor("root");
 		root = root.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION, Arrays.asList(fileImports, classpathImports));
 		assertThat(asLocationsList(root.iterator())).containsExactly("file:application-profile.properties",
 				"file:application.properties", "file:./", "classpath:application-profile.properties",
@@ -221,8 +212,8 @@ class ConfigDataEnvironmentContributorTests {
 
 	@Test
 	void withChildrenReturnsNewInstanceWithChildren() {
-		ConfigDataEnvironmentContributor root = createContributor("root");
+		ConfigDataEnvironmentContributor root = createBoundContributor("root");
-		ConfigDataEnvironmentContributor child = createContributor("child");
+		ConfigDataEnvironmentContributor child = createBoundContributor("child");
 		ConfigDataEnvironmentContributor withChildren = root.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION,
 				Collections.singletonList(child));
 		assertThat(root.getChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isEmpty();
@@ -231,12 +222,12 @@ class ConfigDataEnvironmentContributorTests {
 
 	@Test
 	void withReplacementReplacesChild() {
-		ConfigDataEnvironmentContributor root = createContributor("root");
+		ConfigDataEnvironmentContributor root = createBoundContributor("root");
-		ConfigDataEnvironmentContributor child = createContributor("child");
+		ConfigDataEnvironmentContributor child = createBoundContributor("child");
-		ConfigDataEnvironmentContributor grandchild = createContributor("grandchild");
+		ConfigDataEnvironmentContributor grandchild = createBoundContributor("grandchild");
 		child = child.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION, Collections.singletonList(grandchild));
 		root = root.withChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION, Collections.singletonList(child));
-		ConfigDataEnvironmentContributor updated = createContributor("updated");
+		ConfigDataEnvironmentContributor updated = createBoundContributor("updated");
 		ConfigDataEnvironmentContributor withReplacement = root.withReplacement(grandchild, updated);
 		assertThat(asLocationsList(root.iterator())).containsExactly("grandchild", "child", "root");
 		assertThat(asLocationsList(withReplacement.iterator())).containsExactly("updated", "child", "root");
@@ -244,8 +235,8 @@ class ConfigDataEnvironmentContributorTests {
 
 	@Test
 	void ofCreatesRootContributor() {
-		ConfigDataEnvironmentContributor one = createContributor("one");
+		ConfigDataEnvironmentContributor one = createBoundContributor("one");
-		ConfigDataEnvironmentContributor two = createContributor("two");
+		ConfigDataEnvironmentContributor two = createBoundContributor("two");
 		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.of(Arrays.asList(one, two));
 		assertThat(contributor.getKind()).isEqualTo(Kind.ROOT);
 		assertThat(contributor.getLocation()).isNull();
@@ -284,31 +275,14 @@ class ConfigDataEnvironmentContributorTests {
 	}
 
 	@Test
-	void ofImportedCreatesImportedContributor() {
+	void ofUnboundImportCreatesImportedContributor() {
 		TestLocation location = new TestLocation("test");
 		MockPropertySource propertySource = new MockPropertySource();
 		propertySource.setProperty("spring.config.import", "test");
 		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(location, configData,
+		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofUnboundImport(location,
-				0, this.activationContext);
+				configData, 0);
-		assertThat(contributor.getKind()).isEqualTo(Kind.IMPORTED);
+		assertThat(contributor.getKind()).isEqualTo(Kind.UNBOUND_IMPORT);
-		assertThat(contributor.getLocation()).isSameAs(location);
-		assertThat(contributor.getImports()).containsExactly("test");
-		assertThat(contributor.isActive(this.activationContext)).isTrue();
-		assertThat(contributor.getPropertySource()).isEqualTo(propertySource);
-		assertThat(contributor.getConfigurationPropertySource()).isNotNull();
-		assertThat(contributor.getChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isEmpty();
-	}
-
-	@Test
-	void ofImportedWhenConfigDataHasIgnoreImportsOptionsCreatesImportedContributorWithoutImports() {
-		TestLocation location = new TestLocation("test");
-		MockPropertySource propertySource = new MockPropertySource();
-		propertySource.setProperty("spring.config.import", "test");
-		ConfigData configData = new ConfigData(Collections.singleton(propertySource), ConfigData.Option.IGNORE_IMPORTS);
-		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofImported(location, configData,
-				0, this.activationContext);
-		assertThat(contributor.getKind()).isEqualTo(Kind.IMPORTED);
 		assertThat(contributor.getLocation()).isSameAs(location);
 		assertThat(contributor.getImports()).isEmpty();
 		assertThat(contributor.isActive(this.activationContext)).isTrue();
@@ -318,17 +292,56 @@ class ConfigDataEnvironmentContributorTests {
 	}
 
 	@Test
-	void ofImportedWhenHasUseLegacyPropertyThrowsException() {
+	void bindCreatesImportedContributor() {
+		TestLocation location = new TestLocation("test");
 		MockPropertySource propertySource = new MockPropertySource();
-		propertySource.setProperty("spring.config.use-legacy-processing", "true");
+		propertySource.setProperty("spring.config.import", "test");
-		assertThatExceptionOfType(UseLegacyConfigProcessingException.class)
+		ConfigData configData = new ConfigData(Collections.singleton(propertySource));
-				.isThrownBy(() -> ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(location, configData, 0);
-						new ConfigData(Collections.singleton(propertySource)), 0, this.activationContext));
+		assertThat(contributor.getKind()).isEqualTo(Kind.BOUND_IMPORT);
+		assertThat(contributor.getLocation()).isSameAs(location);
+		assertThat(contributor.getImports()).containsExactly("test");
+		assertThat(contributor.isActive(this.activationContext)).isTrue();
+		assertThat(contributor.getPropertySource()).isEqualTo(propertySource);
+		assertThat(contributor.getConfigurationPropertySource()).isNotNull();
+		assertThat(contributor.getChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isEmpty();
 	}
 
-	private ConfigDataEnvironmentContributor createContributor(String location) {
+	@Test
-		return ConfigDataEnvironmentContributor.ofImported(new TestLocation(location),
+	void bindWhenConfigDataHasIgnoreImportsOptionsCreatesImportedContributorWithoutImports() {
-				new ConfigData(Collections.singleton(new MockPropertySource())), 0, this.activationContext);
+		TestLocation location = new TestLocation("test");
+		MockPropertySource propertySource = new MockPropertySource();
+		propertySource.setProperty("spring.config.import", "test");
+		ConfigData configData = new ConfigData(Collections.singleton(propertySource), ConfigData.Option.IGNORE_IMPORTS);
+		ConfigDataEnvironmentContributor contributor = createBoundContributor(location, configData, 0);
+		assertThat(contributor.getKind()).isEqualTo(Kind.BOUND_IMPORT);
+		assertThat(contributor.getLocation()).isSameAs(location);
+		assertThat(contributor.getImports()).isEmpty();
+		assertThat(contributor.isActive(this.activationContext)).isTrue();
+		assertThat(contributor.getPropertySource()).isEqualTo(propertySource);
+		assertThat(contributor.getConfigurationPropertySource()).isNotNull();
+		assertThat(contributor.getChildren(ImportPhase.BEFORE_PROFILE_ACTIVATION)).isEmpty();
+	}
+
+	@Test
+	void bindWhenHasUseLegacyPropertyThrowsException() {
+		MockPropertySource propertySource = new MockPropertySource();
+		propertySource.setProperty("spring.config.use-legacy-processing", "true");
+		assertThatExceptionOfType(UseLegacyConfigProcessingException.class).isThrownBy(
+				() -> createBoundContributor(null, new ConfigData(Collections.singleton(propertySource)), 0));
+	}
+
+	private ConfigDataEnvironmentContributor createBoundContributor(String location) {
+		return createBoundContributor(new TestLocation(location),
+				new ConfigData(Collections.singleton(new MockPropertySource())), 0);
+	}
+
+	private ConfigDataEnvironmentContributor createBoundContributor(ConfigDataLocation location, ConfigData configData,
+			int propertySourceIndex) {
+		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofUnboundImport(location,
+				configData, propertySourceIndex);
+		Binder binder = new Binder(contributor.getConfigurationPropertySource());
+		return contributor.withBoundProperties(binder);
 	}
 
 	private List<String> asLocationsList(Iterator<ConfigDataEnvironmentContributor> iterator) {

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

@@ -268,10 +268,8 @@ class ConfigDataEnvironmentContributorsTests {
 		MockPropertySource secondPropertySource = new MockPropertySource();
 		secondPropertySource.setProperty("test", "two");
 		ConfigData configData = new ConfigData(Arrays.asList(firstPropertySource, secondPropertySource));
-		ConfigDataEnvironmentContributor firstContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor firstContributor = createBoundImportContributor(configData, 0);
-				configData, 0, this.activationContext);
+		ConfigDataEnvironmentContributor secondContributor = createBoundImportContributor(configData, 1);
-		ConfigDataEnvironmentContributor secondContributor = ConfigDataEnvironmentContributor.ofImported(null,
-				configData, 1, this.activationContext);
 		ConfigDataEnvironmentContributors contributors = new ConfigDataEnvironmentContributors(this.logFactory,
 				this.bootstrapRegistry, Arrays.asList(firstContributor, secondContributor));
 		Binder binder = contributors.getBinder(this.activationContext);
@@ -286,10 +284,8 @@ class ConfigDataEnvironmentContributorsTests {
 		MockPropertySource secondPropertySource = new MockPropertySource();
 		secondPropertySource.setProperty("test", "two");
 		ConfigData configData = new ConfigData(Arrays.asList(firstPropertySource, secondPropertySource));
-		ConfigDataEnvironmentContributor firstContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor firstContributor = createBoundImportContributor(configData, 0);
-				configData, 0, this.activationContext);
+		ConfigDataEnvironmentContributor secondContributor = createBoundImportContributor(configData, 1);
-		ConfigDataEnvironmentContributor secondContributor = ConfigDataEnvironmentContributor.ofImported(null,
-				configData, 1, this.activationContext);
 		ConfigDataEnvironmentContributors contributors = new ConfigDataEnvironmentContributors(this.logFactory,
 				this.bootstrapRegistry, Arrays.asList(firstContributor, secondContributor));
 		Binder binder = contributors.getBinder(this.activationContext);
@@ -317,10 +313,8 @@ class ConfigDataEnvironmentContributorsTests {
 		secondPropertySource.setProperty("other", "two");
 		secondPropertySource.setProperty("test", "${other}");
 		ConfigData configData = new ConfigData(Arrays.asList(firstPropertySource, secondPropertySource));
-		ConfigDataEnvironmentContributor firstContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor firstContributor = createBoundImportContributor(configData, 0);
-				configData, 0, this.activationContext);
+		ConfigDataEnvironmentContributor secondContributor = createBoundImportContributor(configData, 1);
-		ConfigDataEnvironmentContributor secondContributor = ConfigDataEnvironmentContributor.ofImported(null,
-				configData, 1, this.activationContext);
 		ConfigDataEnvironmentContributors contributors = new ConfigDataEnvironmentContributors(this.logFactory,
 				this.bootstrapRegistry, Arrays.asList(firstContributor, secondContributor));
 		Binder binder = contributors.getBinder(this.activationContext);
@@ -335,10 +329,8 @@ class ConfigDataEnvironmentContributorsTests {
 		MockPropertySource secondPropertySource = new MockPropertySource();
 		secondPropertySource.setProperty("test", "two");
 		ConfigData configData = new ConfigData(Arrays.asList(firstPropertySource, secondPropertySource));
-		ConfigDataEnvironmentContributor firstContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor firstContributor = createBoundImportContributor(configData, 0);
-				configData, 0, this.activationContext);
+		ConfigDataEnvironmentContributor secondContributor = createBoundImportContributor(configData, 1);
-		ConfigDataEnvironmentContributor secondContributor = ConfigDataEnvironmentContributor.ofImported(null,
-				configData, 1, this.activationContext);
 		ConfigDataEnvironmentContributors contributors = new ConfigDataEnvironmentContributors(this.logFactory,
 				this.bootstrapRegistry, Arrays.asList(firstContributor, secondContributor));
 		Binder binder = contributors.getBinder(this.activationContext, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);
@@ -354,10 +346,8 @@ class ConfigDataEnvironmentContributorsTests {
 		secondPropertySource.setProperty("spring.config.activate.on-profile", "production");
 		secondPropertySource.setProperty("test", "two");
 		ConfigData configData = new ConfigData(Arrays.asList(firstPropertySource, secondPropertySource));
-		ConfigDataEnvironmentContributor firstContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor firstContributor = createBoundImportContributor(configData, 0);
-				configData, 0, this.activationContext);
+		ConfigDataEnvironmentContributor secondContributor = createBoundImportContributor(configData, 1);
-		ConfigDataEnvironmentContributor secondContributor = ConfigDataEnvironmentContributor.ofImported(null,
-				configData, 1, this.activationContext);
 		ConfigDataEnvironmentContributors contributors = new ConfigDataEnvironmentContributors(this.logFactory,
 				this.bootstrapRegistry, Arrays.asList(firstContributor, secondContributor));
 		Binder binder = contributors.getBinder(this.activationContext, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);
@@ -374,10 +364,8 @@ class ConfigDataEnvironmentContributorsTests {
 		secondPropertySource.setProperty("test", "${other}");
 		secondPropertySource.setProperty("other", "one");
 		ConfigData configData = new ConfigData(Arrays.asList(firstPropertySource, secondPropertySource));
-		ConfigDataEnvironmentContributor firstContributor = ConfigDataEnvironmentContributor.ofImported(null,
+		ConfigDataEnvironmentContributor firstContributor = createBoundImportContributor(configData, 0);
-				configData, 0, this.activationContext);
+		ConfigDataEnvironmentContributor secondContributor = createBoundImportContributor(configData, 1);
-		ConfigDataEnvironmentContributor secondContributor = ConfigDataEnvironmentContributor.ofImported(null,
-				configData, 1, this.activationContext);
 		ConfigDataEnvironmentContributors contributors = new ConfigDataEnvironmentContributors(this.logFactory,
 				this.bootstrapRegistry, Arrays.asList(firstContributor, secondContributor));
 		Binder binder = contributors.getBinder(this.activationContext, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);
@@ -385,6 +373,14 @@ class ConfigDataEnvironmentContributorsTests {
 				.satisfies((ex) -> assertThat(ex.getCause()).isInstanceOf(InactiveConfigDataAccessException.class));
 	}
 
+	private ConfigDataEnvironmentContributor createBoundImportContributor(ConfigData configData,
+			int propertySourceIndex) {
+		ConfigDataEnvironmentContributor contributor = ConfigDataEnvironmentContributor.ofUnboundImport(null,
+				configData, propertySourceIndex);
+		Binder binder = new Binder(contributor.getConfigurationPropertySource());
+		return contributor.withBoundProperties(binder);
+	}
+
 	private static class TestConfigDataLocation extends ConfigDataLocation {
 
 		private final String value;

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

@@ -35,6 +35,7 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.context.properties.bind.BindException;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.env.ConfigurableEnvironment;
@@ -514,6 +515,27 @@ class ConfigDataEnvironmentPostProcessorIntegrationTests {
 				() -> this.application.run("--spring.config.location=classpath:invalidproperty.properties"));
 	}
 
+	@Test
+	void runWhenImportUsesPlaceholder() {
+		ConfigurableApplicationContext context = this.application
+				.run("--spring.config.location=classpath:application-import-with-placeholder.properties");
+		assertThat(context.getEnvironment().getProperty("my.value")).isEqualTo("iwasimported");
+	}
+
+	@Test
+	void runWhenImportFromEarlierDocumentUsesPlaceholder() {
+		ConfigurableApplicationContext context = this.application
+				.run("--spring.config.location=classpath:application-import-with-placeholder-in-document.properties");
+		assertThat(context.getEnvironment().getProperty("my.value")).isEqualTo("iwasimported");
+	}
+
+	@Test
+	void runWhenHasPropertyInProfileDocumentThrowsException() {
+		assertThatExceptionOfType(BindException.class).isThrownBy(() -> this.application.run(
+				"--spring.config.location=classpath:application-import-with-placeholder-in-profile-document.properties"))
+				.withCauseInstanceOf(InactiveConfigDataAccessException.class);
+	}
+
 	private Condition<ConfigurableEnvironment> matchingPropertySource(final String sourceName) {
 		return new Condition<ConfigurableEnvironment>("environment containing property source " + sourceName) {
 

spring-boot-project/spring-boot/src/test/resources/application-import-with-placeholder-imported.properties

@@ -0,0 +1 @@
+my.value=iwasimported

spring-boot-project/spring-boot/src/test/resources/application-import-with-placeholder-in-document.properties

@@ -0,0 +1,3 @@
+my.import=application-import-with-placeholder-imported
+#---
+spring.config.import=classpath:${my.import}.properties

spring-boot-project/spring-boot/src/test/resources/application-import-with-placeholder-in-profile-document.properties

@@ -0,0 +1,6 @@
+my.import=application-import-with-placeholder-imported
+#---
+spring.config.import=classpath:${my.import}.properties
+#---
+my.import=badbadbad
+spring.config.activate.on-profile=missing

spring-boot-project/spring-boot/src/test/resources/application-import-with-placeholder.properties

@@ -0,0 +1,2 @@
+my.import=application-import-with-placeholder-imported
+spring.config.import=classpath:${my.import}.properties