Add OriginTrackedMapPropertySource

Add `OriginTrackedMapPropertySource` that can be used for any `Map`
backed `PropertySource` that is also aware property origins. Rather than
directly storing the value in the `Map`, an `OriginTrackedValue` can
be used.

See gh-8142
See gh-8517

spring-boot/src/main/java/org/springframework/boot/env/OriginTrackedMapPropertySource.java

@@ -0,0 +1,57 @@
+/*
+ * 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.env;
+
+import java.util.Map;
+
+import org.springframework.core.env.MapPropertySource;
+
+/**
+ * {@link OriginCapablePropertySource} backed by a {@link Map} containing
+ * {@link OriginTrackedValue OriginTrackedValues}.
+ *
+ * @author Madhura Bhave
+ * @author Phillip Webb
+ * @see OriginTrackedValue
+ */
+class OriginTrackedMapPropertySource extends MapPropertySource
+		implements OriginCapablePropertySource {
+
+	@SuppressWarnings({ "unchecked", "rawtypes" })
+	OriginTrackedMapPropertySource(String name, Map source) {
+		super(name, source);
+	}
+
+	@Override
+	public Object getProperty(String name) {
+		Object value = super.getProperty(name);
+		if (value instanceof OriginTrackedValue) {
+			return ((OriginTrackedValue) value).getValue();
+		}
+		return value;
+	}
+
+	@Override
+	public PropertyOrigin getPropertyOrigin(String name) {
+		Object value = super.getProperty(name);
+		if (value instanceof OriginTrackedValue) {
+			return ((OriginTrackedValue) value).getOrigin();
+		}
+		return null;
+	}
+
+}

spring-boot/src/main/java/org/springframework/boot/env/OriginTrackedValue.java

@@ -0,0 +1,113 @@
+/*
+ * 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.env;
+
+/**
+ * Wrapper class for an Object {@code value} and {@link PropertyOrigin origin}.
+ *
+ * @author Madhura Bhave
+ * @see OriginTrackedMapPropertySource
+ */
+class OriginTrackedValue {
+
+	private final Object value;
+
+	private final PropertyOrigin origin;
+
+	OriginTrackedValue(Object value, PropertyOrigin origin) {
+		this.value = value;
+		this.origin = origin;
+	}
+
+	public Object getValue() {
+		return this.value;
+	}
+
+	public PropertyOrigin getOrigin() {
+		return this.origin;
+	}
+
+	@Override
+	public String toString() {
+		return this.value.toString();
+	}
+
+	@Override
+	public int hashCode() {
+		return this.value.hashCode();
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (obj == null || obj.getClass() != getClass()) {
+			return false;
+		}
+		return this.value.equals(((OriginTrackedValue) obj).value);
+	}
+
+	/**
+	 * Create an {@link OriginTrackedValue} containing the specified {@code value} and
+	 * {@code origin}. If the source value implements {@link CharSequence} then so will
+	 * the resulting {@link OriginTrackedValue}.
+	 * @param value the source value
+	 * @param origin the origin
+	 * @return a {@link OriginTrackedValue} or {@code null} if the source value was
+	 * {@code null}.
+	 */
+	public static OriginTrackedValue of(Object value, PropertyOrigin origin) {
+		if (value == null) {
+			return null;
+		}
+		if (value instanceof CharSequence) {
+			return new OriginTrackedCharSequence((CharSequence) value, origin);
+		}
+		return new OriginTrackedValue(value, origin);
+	}
+
+	/**
+	 * {@link OriginTrackedValue} for a {@link CharSequence}.
+	 */
+	private static class OriginTrackedCharSequence extends OriginTrackedValue
+			implements CharSequence {
+
+		OriginTrackedCharSequence(CharSequence value, PropertyOrigin origin) {
+			super(value, origin);
+		}
+
+		@Override
+		public int length() {
+			return getValue().length();
+		}
+
+		@Override
+		public char charAt(int index) {
+			return getValue().charAt(index);
+		}
+
+		@Override
+		public CharSequence subSequence(int start, int end) {
+			return getValue().subSequence(start, end);
+		}
+
+		@Override
+		public CharSequence getValue() {
+			return (CharSequence) super.getValue();
+		}
+
+	}
+
+}

spring-boot/src/test/java/org/springframework/boot/env/OriginTrackedMapPropertySourceTests.java

@@ -0,0 +1,76 @@
+/*
+ * 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.env;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link OriginTrackedMapPropertySource}.
+ *
+ * @author Madhura Bhave
+ * @author Phillip Webb
+ */
+public class OriginTrackedMapPropertySourceTests {
+
+	private Map<String, Object> map = new LinkedHashMap<>();
+
+	private OriginTrackedMapPropertySource source = new OriginTrackedMapPropertySource(
+			"test", this.map);
+
+	private PropertyOrigin origin = mock(PropertyOrigin.class);
+
+	@Test
+	public void getPropertyWhenMissingShouldReturnNull() throws Exception {
+		assertThat(this.source.getProperty("test")).isNull();
+	}
+
+	@Test
+	public void getPropertyWhenNonTrackedShouldReturnValue() throws Exception {
+		this.map.put("test", "foo");
+		assertThat(this.source.getProperty("test")).isEqualTo("foo");
+	}
+
+	@Test
+	public void getPropertyWhenTrackedShouldReturnValue() throws Exception {
+		this.map.put("test", new OriginTrackedValue("foo", this.origin));
+		assertThat(this.source.getProperty("test")).isEqualTo("foo");
+	}
+
+	@Test
+	public void getPropertyOriginWhenMissingShouldReturnNull() throws Exception {
+		assertThat(this.source.getPropertyOrigin("test")).isNull();
+	}
+
+	@Test
+	public void getPropertyOriginWhenNonTrackedShouldReturnNull() throws Exception {
+		this.map.put("test", "foo");
+		assertThat(this.source.getPropertyOrigin("test")).isNull();
+	}
+
+	@Test
+	public void getPropertyOriginWhenTrackedShouldReturnOrigin() throws Exception {
+		this.map.put("test", new OriginTrackedValue("foo", this.origin));
+		assertThat(this.source.getPropertyOrigin("test")).isEqualTo(this.origin);
+	}
+
+}