Refactor PropertySourcesDeducer

Prior to the changes that fixed #12451,
`FilteredPropertySources` and `CompositePropertySources` were required
by the `PropertySourcesDeducer` to ensure that configuration properties binding
could see changes to the environment even when there was a
PropertySourcesPlaceholderConfigurer in the context. #12451 changed the way
property sources are adapted by `SpringConfigurationPropertySources`, removing the
need for `FilteredPropertySources` and `CompositePropertySources`.

Fixes gh-13738

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/CompositePropertySources.java

@@ -1,70 +0,0 @@
-/*
- * Copyright 2012-2018 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
- *
- *      http://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.context.properties;
-
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.List;
-import java.util.stream.StreamSupport;
-
-import org.springframework.core.env.PropertySource;
-import org.springframework.core.env.PropertySources;
-
-/**
- * A composite {@link PropertySources} backed by one or more {@code PropertySources}.
- * Changes to the backing {@code PropertySources} are automatically reflected in the
- * composite.
- *
- * @author Andy Wilkinson
- */
-final class CompositePropertySources implements PropertySources {
-
-	private final List<PropertySources> propertySources;
-
-	CompositePropertySources(PropertySources... propertySources) {
-		this.propertySources = Arrays.asList(propertySources);
-	}
-
-	@Override
-	public Iterator<PropertySource<?>> iterator() {
-		return this.propertySources.stream()
-				.flatMap((sources) -> StreamSupport.stream(sources.spliterator(), false))
-				.iterator();
-	}
-
-	@Override
-	public boolean contains(String name) {
-		for (PropertySources sources : this.propertySources) {
-			if (sources.contains(name)) {
-				return true;
-			}
-		}
-		return false;
-	}
-
-	@Override
-	public PropertySource<?> get(String name) {
-		for (PropertySources sources : this.propertySources) {
-			PropertySource<?> source = sources.get(name);
-			if (source != null) {
-				return source;
-			}
-		}
-		return null;
-	}
-
-}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/FilteredPropertySources.java

@@ -1,74 +0,0 @@
-/*
- * Copyright 2012-2017 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
- *
- *      http://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.context.properties;
-
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.Iterator;
-import java.util.Set;
-import java.util.stream.StreamSupport;
-
-import org.springframework.core.env.PropertySource;
-import org.springframework.core.env.PropertySources;
-
-/**
- * A {@link PropertySources} decorator that filters property sources by name.
- *
- * @author Andy Wilkinson
- */
-final class FilteredPropertySources implements PropertySources {
-
-	private final PropertySources delegate;
-
-	private final Set<String> filtered;
-
-	FilteredPropertySources(PropertySources delegate, String... filtered) {
-		this.delegate = delegate;
-		this.filtered = new HashSet<>(Arrays.asList(filtered));
-	}
-
-	@Override
-	public boolean contains(String name) {
-		if (included(name)) {
-			return this.delegate.contains(name);
-		}
-		return false;
-	}
-
-	@Override
-	public PropertySource<?> get(String name) {
-		if (included(name)) {
-			return this.delegate.get(name);
-		}
-		return null;
-	}
-
-	@Override
-	public Iterator<PropertySource<?>> iterator() {
-		return StreamSupport.stream(this.delegate.spliterator(), false)
-				.filter(this::included).iterator();
-	}
-
-	private boolean included(PropertySource<?> propertySource) {
-		return included(propertySource.getName());
-	}
-
-	private boolean included(String name) {
-		return (!this.filtered.contains(name));
-	}
-
-}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/PropertySourcesDeducer.java

@@ -27,7 +27,6 @@ import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
 import org.springframework.core.env.MutablePropertySources;
 import org.springframework.core.env.PropertySources;
-import org.springframework.util.Assert;
 
 /**
  * Utility to deduce the {@link PropertySources} to use for configuration binding.
@@ -45,20 +44,16 @@ class PropertySourcesDeducer {
 	}
 
 	public PropertySources getPropertySources() {
-		MutablePropertySources environmentPropertySources = extractEnvironmentPropertySources();
+		PropertySourcesPlaceholderConfigurer configurer = getSinglePropertySourcesPlaceholderConfigurer();
-		PropertySourcesPlaceholderConfigurer placeholderConfigurer = getSinglePropertySourcesPlaceholderConfigurer();
+		if (configurer != null) {
-		if (placeholderConfigurer == null) {
+			return configurer.getAppliedPropertySources();
-			Assert.state(environmentPropertySources != null,
-					"Unable to obtain PropertySources from "
-							+ "PropertySourcesPlaceholderConfigurer or Environment");
-			return environmentPropertySources;
 		}
-		PropertySources appliedPropertySources = placeholderConfigurer
+		MutablePropertySources sources = extractEnvironmentPropertySources();
-				.getAppliedPropertySources();
+		if (sources != null) {
-		if (environmentPropertySources == null) {
+			return sources;
-			return appliedPropertySources;
 		}
-		return merge(environmentPropertySources, appliedPropertySources);
+		throw new IllegalStateException("Unable to obtain PropertySources from "
+				+ "PropertySourcesPlaceholderConfigurer or Environment");
 	}
 
 	private MutablePropertySources extractEnvironmentPropertySources() {
@@ -84,12 +79,4 @@ class PropertySourcesDeducer {
 		return null;
 	}
 
-	private PropertySources merge(PropertySources environmentPropertySources,
-			PropertySources appliedPropertySources) {
-		FilteredPropertySources filtered = new FilteredPropertySources(
-				appliedPropertySources,
-				PropertySourcesPlaceholderConfigurer.ENVIRONMENT_PROPERTIES_PROPERTY_SOURCE_NAME);
-		return new CompositePropertySources(filtered, environmentPropertySources);
-	}
-
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/CompositePropertySourcesTests.java

@@ -1,144 +0,0 @@
-/*
- * Copyright 2012-2017 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
- *
- *      http://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.context.properties;
-
-import java.util.Collections;
-
-import org.junit.Test;
-
-import org.springframework.core.env.MapPropertySource;
-import org.springframework.core.env.MutablePropertySources;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-/**
- * Tests for {@link CompositePropertySources}.
- *
- * @author Andy Wilkinson
- */
-public class CompositePropertySourcesTests {
-
-	@Test
-	public void containsReturnsFalseWithNoBackingSources() {
-		assertThat(new CompositePropertySources().contains("foo")).isFalse();
-	}
-
-	@Test
-	public void getReturnsNullWithNoBackingSources() {
-		assertThat(new CompositePropertySources().get("foo")).isNull();
-	}
-
-	@Test
-	public void iteratorIsEmptyWithNoBackingSources() {
-		assertThat(new CompositePropertySources().iterator()).hasSize(0);
-	}
-
-	@Test
-	public void containsReturnsTrueForPropertySourceFoundInBackingSources() {
-		MutablePropertySources sources = new MutablePropertySources();
-		sources.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		assertThat(new CompositePropertySources(sources).contains("foo")).isTrue();
-	}
-
-	@Test
-	public void containsReturnsFalseForPropertySourceNotFoundInBackingSources() {
-		MutablePropertySources sources = new MutablePropertySources();
-		sources.addFirst(new MapPropertySource("bar", Collections.emptyMap()));
-		assertThat(new CompositePropertySources(sources).contains("foo")).isFalse();
-	}
-
-	@Test
-	public void getReturnsPropertySourceFoundInBackingSources() {
-		MutablePropertySources sources = new MutablePropertySources();
-		MapPropertySource fooSource = new MapPropertySource("foo",
-				Collections.emptyMap());
-		sources.addFirst(fooSource);
-		assertThat(new CompositePropertySources(sources).get("foo")).isEqualTo(fooSource);
-	}
-
-	@Test
-	public void getReturnsNullWhenPropertySourceNotFoundInBackingSources() {
-		MutablePropertySources sources = new MutablePropertySources();
-		sources.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		assertThat(new CompositePropertySources(sources).get("bar")).isNull();
-	}
-
-	@Test
-	public void iteratorContainsSingleEntryWithSingleBackingSource() {
-		MutablePropertySources sources = new MutablePropertySources();
-		MapPropertySource fooSource = new MapPropertySource("foo",
-				Collections.emptyMap());
-		sources.addFirst(fooSource);
-		assertThat(new CompositePropertySources(sources).iterator())
-				.containsExactly(fooSource);
-	}
-
-	@Test
-	public void iteratorReflectsOrderingOfSourcesAcrossMultipleBackingSources() {
-		MutablePropertySources sourcesOne = new MutablePropertySources();
-		MapPropertySource fooSource = new MapPropertySource("foo",
-				Collections.emptyMap());
-		sourcesOne.addFirst(fooSource);
-		MapPropertySource barSource = new MapPropertySource("bar",
-				Collections.emptyMap());
-		sourcesOne.addFirst(barSource);
-		MutablePropertySources sourcesTwo = new MutablePropertySources();
-		MapPropertySource bazSource = new MapPropertySource("baz",
-				Collections.emptyMap());
-		sourcesTwo.addFirst(bazSource);
-		assertThat(new CompositePropertySources(sourcesOne, sourcesTwo).iterator())
-				.containsExactly(barSource, fooSource, bazSource);
-	}
-
-	@Test
-	public void containsReflectsChangesInTheBackingSources() {
-		MutablePropertySources sources = new MutablePropertySources();
-		sources.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		assertThat(new CompositePropertySources(sources).contains("bar")).isFalse();
-		MapPropertySource barSource = new MapPropertySource("bar",
-				Collections.emptyMap());
-		sources.addFirst(barSource);
-		assertThat(new CompositePropertySources(sources).contains("bar")).isTrue();
-	}
-
-	@Test
-	public void getReflectsChangesInTheBackingSources() {
-		MutablePropertySources sources = new MutablePropertySources();
-		sources.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		assertThat(new CompositePropertySources(sources).get("bar")).isNull();
-		MapPropertySource barSource = new MapPropertySource("bar",
-				Collections.emptyMap());
-		sources.addFirst(barSource);
-		assertThat(new CompositePropertySources(sources).get("bar")).isEqualTo(barSource);
-	}
-
-	@Test
-	public void iteratorReflectsChangesInTheBackingSources() {
-		MutablePropertySources sources = new MutablePropertySources();
-		MapPropertySource fooSource = new MapPropertySource("foo",
-				Collections.emptyMap());
-		sources.addFirst(fooSource);
-		assertThat(new CompositePropertySources(sources).iterator())
-				.containsExactly(fooSource);
-		MapPropertySource barSource = new MapPropertySource("bar",
-				Collections.emptyMap());
-		sources.addFirst(barSource);
-		assertThat(new CompositePropertySources(sources).iterator())
-				.containsExactly(barSource, fooSource);
-	}
-
-}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/ConfigurationPropertiesTests.java

@@ -25,6 +25,7 @@ import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Properties;
 import java.util.Set;
 
 import javax.annotation.PostConstruct;
@@ -352,6 +353,15 @@ public class ConfigurationPropertiesTests {
 		assertThat(bean.getValue()).isEqualTo("foo");
 	}
 
+	@Test
+	public void loadWithPropertyPlaceholderShouldNotAlterPropertySourceOrder() {
+		load(WithPropertyPlaceholderWithLocalPropertiesValueConfiguration.class,
+				"com.example.bar=a");
+		SimplePrefixedProperties bean = this.context
+				.getBean(SimplePrefixedProperties.class);
+		assertThat(bean.getBar()).isEqualTo("a");
+	}
+
 	@Test
 	public void loadWhenHasPostConstructShouldTriggerPostConstructWithBoundBean() {
 		MockEnvironment environment = new MockEnvironment();
@@ -959,6 +969,21 @@ public class ConfigurationPropertiesTests {
 
 	}
 
+	@Configuration
+	@EnableConfigurationProperties(SimplePrefixedProperties.class)
+	static class WithPropertyPlaceholderWithLocalPropertiesValueConfiguration {
+
+		@Bean
+		public static PropertySourcesPlaceholderConfigurer configurer() {
+			PropertySourcesPlaceholderConfigurer placeholderConfigurer = new PropertySourcesPlaceholderConfigurer();
+			Properties properties = new Properties();
+			properties.put("com.example.bar", "b");
+			placeholderConfigurer.setProperties(properties);
+			return placeholderConfigurer;
+		}
+
+	}
+
 	@Configuration
 	@EnableConfigurationProperties
 	static class WithFactoryBeanConfiguration {

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/FilteredPropertySourcesTests.java

@@ -1,85 +0,0 @@
-/*
- * Copyright 2012-2017 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
- *
- *      http://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.context.properties;
-
-import java.util.Collections;
-
-import org.junit.Test;
-
-import org.springframework.core.env.MapPropertySource;
-import org.springframework.core.env.MutablePropertySources;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-/**
- * Tests for {@link FilteredPropertySources}.
- *
- * @author Andy Wilkinson
- */
-public class FilteredPropertySourcesTests {
-
-	@Test
-	public void getReturnsNullForFilteredSource() {
-		MutablePropertySources delegate = new MutablePropertySources();
-		delegate.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		assertThat(new FilteredPropertySources(delegate, "foo").get("foo")).isNull();
-	}
-
-	@Test
-	public void getReturnsSourceThatIsNotFiltered() {
-		MutablePropertySources delegate = new MutablePropertySources();
-		delegate.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		MapPropertySource barSource = new MapPropertySource("bar",
-				Collections.emptyMap());
-		delegate.addFirst(barSource);
-		assertThat(new FilteredPropertySources(delegate, "foo").get("bar"))
-				.isEqualTo(barSource);
-	}
-
-	@Test
-	public void containsReturnsFalseForFilteredSource() {
-		MutablePropertySources delegate = new MutablePropertySources();
-		delegate.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		assertThat(new FilteredPropertySources(delegate, "foo").contains("foo"))
-				.isFalse();
-	}
-
-	@Test
-	public void containsReturnsTrueForSourceThatIsNotFiltered() {
-		MutablePropertySources delegate = new MutablePropertySources();
-		delegate.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		MapPropertySource barSource = new MapPropertySource("bar",
-				Collections.emptyMap());
-		delegate.addFirst(barSource);
-		assertThat(new FilteredPropertySources(delegate, "foo").contains("bar")).isTrue();
-	}
-
-	@Test
-	public void iteratorOmitsSourceThatIsFiltered() {
-		MutablePropertySources delegate = new MutablePropertySources();
-		MapPropertySource barSource = new MapPropertySource("bar",
-				Collections.emptyMap());
-		delegate.addFirst(barSource);
-		delegate.addFirst(new MapPropertySource("foo", Collections.emptyMap()));
-		MapPropertySource bazSource = new MapPropertySource("baz",
-				Collections.emptyMap());
-		delegate.addFirst(bazSource);
-		assertThat(new FilteredPropertySources(delegate, "foo").iterator())
-				.containsExactly(bazSource, barSource);
-	}
-
-}