Add multi-document properties file support

Update `OriginTrackedPropertiesLoader` so that it can support
multi-document properties files. These are similar to multi-document
YAML files but use `#---` as the separator.

Closes gh-22495
Co-authored-by: Phillip Webb <pwebb@vmware.com>

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/env/OriginTrackedPropertiesLoader.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -21,8 +21,11 @@ import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.LineNumberReader;
 import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
+import java.util.function.BooleanSupplier;
 
 import org.springframework.boot.origin.Origin;
 import org.springframework.boot.origin.OriginTrackedValue;
@@ -59,7 +62,7 @@ class OriginTrackedPropertiesLoader {
 	 * @return the loaded properties
 	 * @throws IOException on read error
 	 */
-	Map<String, OriginTrackedValue> load() throws IOException {
+	List<Document> load() throws IOException {
 		return load(true);
 	}
 
@@ -70,18 +73,30 @@ class OriginTrackedPropertiesLoader {
 	 * @return the loaded properties
 	 * @throws IOException on read error
 	 */
-	Map<String, OriginTrackedValue> load(boolean expandLists) throws IOException {
+	List<Document> load(boolean expandLists) throws IOException {
+		List<Document> result = new ArrayList<>();
+		Document document = new Document();
 		try (CharacterReader reader = new CharacterReader(this.resource)) {
-			Map<String, OriginTrackedValue> result = new LinkedHashMap<>();
 			StringBuilder buffer = new StringBuilder();
 			while (reader.read()) {
+				if (reader.getCharacter() == '#') {
+					if (isNewDocument(reader)) {
+						if (!document.isEmpty()) {
+							result.add(document);
+						}
+						document = new Document();
+					}
+					else {
+						reader.skipComment();
+					}
+				}
 				String key = loadKey(buffer, reader).trim();
 				if (expandLists && key.endsWith("[]")) {
 					key = key.substring(0, key.length() - 2);
 					int index = 0;
 					do {
 						OriginTrackedValue value = loadValue(buffer, reader, true);
-						put(result, key + "[" + (index++) + "]", value);
+						document.put(key + "[" + (index++) + "]", value);
 						if (!reader.isEndOfLine()) {
 							reader.read();
 						}
@@ -90,17 +105,15 @@ class OriginTrackedPropertiesLoader {
 				}
 				else {
 					OriginTrackedValue value = loadValue(buffer, reader, false);
-					put(result, key, value);
+					document.put(key, value);
 				}
 			}
-			return result;
-		}
-	}
 
-	private void put(Map<String, OriginTrackedValue> result, String key, OriginTrackedValue value) {
-		if (!key.isEmpty()) {
-			result.put(key, value);
 		}
+		if (!document.isEmpty() && !result.contains(document)) {
+			result.add(document);
+		}
+		return result;
 	}
 
 	private String loadKey(StringBuilder buffer, CharacterReader reader) throws IOException {
@@ -136,6 +149,20 @@ class OriginTrackedPropertiesLoader {
 		return OriginTrackedValue.of(buffer.toString(), origin);
 	}
 
+	boolean isNewDocument(CharacterReader reader) throws IOException {
+		boolean result = reader.isPoundCharacter();
+		result = result && readAndExpect(reader, reader::isHyphenCharacter);
+		result = result && readAndExpect(reader, reader::isHyphenCharacter);
+		result = result && readAndExpect(reader, reader::isHyphenCharacter);
+		result = result && readAndExpect(reader, reader::isEndOfLine);
+		return result;
+	}
+
+	private boolean readAndExpect(CharacterReader reader, BooleanSupplier check) throws IOException {
+		reader.read();
+		return check.getAsBoolean();
+	}
+
 	/**
 	 * Reads characters from the source resource, taking care of skipping comments,
 	 * handling multi-line values and tracking {@code '\'} escapes.
@@ -173,7 +200,9 @@ class OriginTrackedPropertiesLoader {
 			if (this.columnNumber == 0) {
 				skipLeadingWhitespace();
 				if (!wrappedLine) {
-					skipComment();
+					if (this.character == '!') {
+						skipComment();
+					}
 				}
 			}
 			if (this.character == '\\') {
@@ -194,13 +223,10 @@ class OriginTrackedPropertiesLoader {
 		}
 
 		private void skipComment() throws IOException {
-			if (this.character == '#' || this.character == '!') {
-				while (this.character != '\n' && this.character != -1) {
-					this.character = this.reader.read();
-				}
-				this.columnNumber = -1;
-				read();
+			while (this.character != '\n' && this.character != -1) {
+				this.character = this.reader.read();
 			}
+			this.columnNumber = -1;
 		}
 
 		private void readEscaped() throws IOException {
@@ -265,6 +291,37 @@ class OriginTrackedPropertiesLoader {
 			return new Location(this.reader.getLineNumber(), this.columnNumber);
 		}
 
+		boolean isPoundCharacter() {
+			return this.character == '#';
+		}
+
+		boolean isHyphenCharacter() {
+			return this.character == '-';
+		}
+
+	}
+
+	/**
+	 * A single document within the properties file.
+	 */
+	static class Document {
+
+		private final Map<String, OriginTrackedValue> values = new LinkedHashMap<>();
+
+		void put(String key, OriginTrackedValue value) {
+			if (!key.isEmpty()) {
+				this.values.put(key, value);
+			}
+		}
+
+		boolean isEmpty() {
+			return this.values.isEmpty();
+		}
+
+		Map<String, OriginTrackedValue> asMap() {
+			return this.values;
+		}
+
 	}
 
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/env/PropertiesPropertySourceLoader.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -17,10 +17,12 @@
 package org.springframework.boot.env;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.boot.env.OriginTrackedPropertiesLoader.Document;
 import org.springframework.core.env.PropertySource;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.support.PropertiesLoaderUtils;
@@ -44,21 +46,31 @@ public class PropertiesPropertySourceLoader implements PropertySourceLoader {
 
 	@Override
 	public List<PropertySource<?>> load(String name, Resource resource) throws IOException {
-		Map<String, ?> properties = loadProperties(resource);
+		List<Map<String, ?>> properties = loadProperties(resource);
 		if (properties.isEmpty()) {
 			return Collections.emptyList();
 		}
-		return Collections
-				.singletonList(new OriginTrackedMapPropertySource(name, Collections.unmodifiableMap(properties), true));
+		List<PropertySource<?>> propertySources = new ArrayList<>(properties.size());
+		for (int i = 0; i < properties.size(); i++) {
+			String documentNumber = (properties.size() != 1) ? " (document #" + i + ")" : "";
+			propertySources.add(new OriginTrackedMapPropertySource(name + documentNumber,
+					Collections.unmodifiableMap(properties.get(i)), true));
+		}
+		return propertySources;
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })
-	private Map<String, ?> loadProperties(Resource resource) throws IOException {
+	private List<Map<String, ?>> loadProperties(Resource resource) throws IOException {
 		String filename = resource.getFilename();
+		List<Map<String, ?>> result = new ArrayList<>();
 		if (filename != null && filename.endsWith(XML_FILE_EXTENSION)) {
-			return (Map) PropertiesLoaderUtils.loadProperties(resource);
+			result.add((Map) PropertiesLoaderUtils.loadProperties(resource));
+		}
+		else {
+			List<Document> documents = new OriginTrackedPropertiesLoader(resource).load();
+			documents.forEach((document) -> result.add(document.asMap()));
 		}
-		return new OriginTrackedPropertiesLoader(resource).load();
+		return result;
 	}
 
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/env/OriginTrackedPropertiesLoaderTests.java

@@ -16,12 +16,13 @@
 
 package org.springframework.boot.env;
 
-import java.util.Map;
+import java.util.List;
 import java.util.Properties;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import org.springframework.boot.env.OriginTrackedPropertiesLoader.Document;
 import org.springframework.boot.origin.OriginTrackedValue;
 import org.springframework.boot.origin.TextResourceOrigin;
 import org.springframework.core.io.ClassPathResource;
@@ -40,47 +41,48 @@ class OriginTrackedPropertiesLoaderTests {
 
 	private ClassPathResource resource;
 
-	private Map<String, OriginTrackedValue> properties;
+	private List<Document> documentes;
 
 	@BeforeEach
 	void setUp() throws Exception {
 		String path = "test-properties.properties";
 		this.resource = new ClassPathResource(path, getClass());
-		this.properties = new OriginTrackedPropertiesLoader(this.resource).load();
+		this.documentes = new OriginTrackedPropertiesLoader(this.resource).load();
 	}
 
 	@Test
 	void compareToJavaProperties() throws Exception {
 		Properties java = PropertiesLoaderUtils.loadProperties(this.resource);
 		Properties ours = new Properties();
-		new OriginTrackedPropertiesLoader(this.resource).load(false).forEach((k, v) -> ours.put(k, v.getValue()));
+		new OriginTrackedPropertiesLoader(this.resource).load(false).get(0).asMap()
+				.forEach((k, v) -> ours.put(k, v.getValue()));
 		assertThat(ours).isEqualTo(java);
 	}
 
 	@Test
 	void getSimpleProperty() {
-		OriginTrackedValue value = this.properties.get("test");
+		OriginTrackedValue value = getFromFirst("test");
 		assertThat(getValue(value)).isEqualTo("properties");
 		assertThat(getLocation(value)).isEqualTo("11:6");
 	}
 
 	@Test
 	void getSimplePropertyWithColonSeparator() {
-		OriginTrackedValue value = this.properties.get("test-colon-separator");
+		OriginTrackedValue value = getFromFirst("test-colon-separator");
 		assertThat(getValue(value)).isEqualTo("my-property");
 		assertThat(getLocation(value)).isEqualTo("15:23");
 	}
 
 	@Test
 	void getPropertyWithSeparatorSurroundedBySpaces() {
-		OriginTrackedValue value = this.properties.get("blah");
+		OriginTrackedValue value = getFromFirst("blah");
 		assertThat(getValue(value)).isEqualTo("hello world");
 		assertThat(getLocation(value)).isEqualTo("2:12");
 	}
 
 	@Test
 	void getUnicodeProperty() {
-		OriginTrackedValue value = this.properties.get("test-unicode");
+		OriginTrackedValue value = getFromFirst("test-unicode");
 		assertThat(getValue(value)).isEqualTo("properties&test");
 		assertThat(getLocation(value)).isEqualTo("12:14");
 	}
@@ -95,165 +97,169 @@ class OriginTrackedPropertiesLoaderTests {
 
 	@Test
 	void getEscapedProperty() {
-		OriginTrackedValue value = this.properties.get("test=property");
+		OriginTrackedValue value = getFromFirst("test=property");
 		assertThat(getValue(value)).isEqualTo("helloworld");
 		assertThat(getLocation(value)).isEqualTo("14:15");
 	}
 
 	@Test
 	void getPropertyWithTab() {
-		OriginTrackedValue value = this.properties.get("test-tab-property");
+		OriginTrackedValue value = getFromFirst("test-tab-property");
 		assertThat(getValue(value)).isEqualTo("foo\tbar");
 		assertThat(getLocation(value)).isEqualTo("16:19");
 	}
 
 	@Test
 	void getPropertyWithBang() {
-		OriginTrackedValue value = this.properties.get("test-bang-property");
+		OriginTrackedValue value = getFromFirst("test-bang-property");
 		assertThat(getValue(value)).isEqualTo("foo!");
 		assertThat(getLocation(value)).isEqualTo("34:20");
 	}
 
 	@Test
 	void getPropertyWithValueComment() {
-		OriginTrackedValue value = this.properties.get("test-property-value-comment");
+		OriginTrackedValue value = getFromFirst("test-property-value-comment");
 		assertThat(getValue(value)).isEqualTo("foo !bar #foo");
 		assertThat(getLocation(value)).isEqualTo("36:29");
 	}
 
 	@Test
 	void getPropertyWithMultilineImmediateBang() {
-		OriginTrackedValue value = this.properties.get("test-multiline-immediate-bang");
+		OriginTrackedValue value = getFromFirst("test-multiline-immediate-bang");
 		assertThat(getValue(value)).isEqualTo("!foo");
 		assertThat(getLocation(value)).isEqualTo("39:1");
 	}
 
 	@Test
 	void getPropertyWithCarriageReturn() {
-		OriginTrackedValue value = this.properties.get("test-return-property");
+		OriginTrackedValue value = getFromFirst("test-return-property");
 		assertThat(getValue(value)).isEqualTo("foo\rbar");
 		assertThat(getLocation(value)).isEqualTo("17:22");
 	}
 
 	@Test
 	void getPropertyWithNewLine() {
-		OriginTrackedValue value = this.properties.get("test-newline-property");
+		OriginTrackedValue value = getFromFirst("test-newline-property");
 		assertThat(getValue(value)).isEqualTo("foo\nbar");
 		assertThat(getLocation(value)).isEqualTo("18:23");
 	}
 
 	@Test
 	void getPropertyWithFormFeed() {
-		OriginTrackedValue value = this.properties.get("test-form-feed-property");
+		OriginTrackedValue value = getFromFirst("test-form-feed-property");
 		assertThat(getValue(value)).isEqualTo("foo\fbar");
 		assertThat(getLocation(value)).isEqualTo("19:25");
 	}
 
 	@Test
 	void getPropertyWithWhiteSpace() {
-		OriginTrackedValue value = this.properties.get("test-whitespace-property");
+		OriginTrackedValue value = getFromFirst("test-whitespace-property");
 		assertThat(getValue(value)).isEqualTo("foo   bar");
 		assertThat(getLocation(value)).isEqualTo("20:32");
 	}
 
 	@Test
 	void getCommentedOutPropertyShouldBeNull() {
-		assertThat(this.properties.get("commented-property")).isNull();
-		assertThat(this.properties.get("#commented-property")).isNull();
-		assertThat(this.properties.get("commented-two")).isNull();
-		assertThat(this.properties.get("!commented-two")).isNull();
+		assertThat(getFromFirst("commented-property")).isNull();
+		assertThat(getFromFirst("#commented-property")).isNull();
+		assertThat(getFromFirst("commented-two")).isNull();
+		assertThat(getFromFirst("!commented-two")).isNull();
 	}
 
 	@Test
 	void getMultiline() {
-		OriginTrackedValue value = this.properties.get("test-multiline");
+		OriginTrackedValue value = getFromFirst("test-multiline");
 		assertThat(getValue(value)).isEqualTo("ab\\c");
 		assertThat(getLocation(value)).isEqualTo("21:17");
 	}
 
 	@Test
 	void getImmediateMultiline() {
-		OriginTrackedValue value = this.properties.get("test-multiline-immediate");
+		OriginTrackedValue value = getFromFirst("test-multiline-immediate");
 		assertThat(getValue(value)).isEqualTo("foo");
 		assertThat(getLocation(value)).isEqualTo("32:1");
 	}
 
 	@Test
 	void getPropertyWithWhitespaceAfterKey() {
-		OriginTrackedValue value = this.properties.get("bar");
+		OriginTrackedValue value = getFromFirst("bar");
 		assertThat(getValue(value)).isEqualTo("foo=baz");
 		assertThat(getLocation(value)).isEqualTo("3:7");
 	}
 
 	@Test
 	void getPropertyWithSpaceSeparator() {
-		OriginTrackedValue value = this.properties.get("hello");
+		OriginTrackedValue value = getFromFirst("hello");
 		assertThat(getValue(value)).isEqualTo("world");
 		assertThat(getLocation(value)).isEqualTo("4:9");
 	}
 
 	@Test
 	void getPropertyWithBackslashEscaped() {
-		OriginTrackedValue value = this.properties.get("proper\\ty");
+		OriginTrackedValue value = getFromFirst("proper\\ty");
 		assertThat(getValue(value)).isEqualTo("test");
 		assertThat(getLocation(value)).isEqualTo("5:11");
 	}
 
 	@Test
 	void getPropertyWithEmptyValue() {
-		OriginTrackedValue value = this.properties.get("foo");
+		OriginTrackedValue value = getFromFirst("foo");
 		assertThat(getValue(value)).isEqualTo("");
 		assertThat(getLocation(value)).isEqualTo("7:0");
 	}
 
 	@Test
 	void getPropertyWithBackslashEscapedInValue() {
-		OriginTrackedValue value = this.properties.get("bat");
+		OriginTrackedValue value = getFromFirst("bat");
 		assertThat(getValue(value)).isEqualTo("a\\");
 		assertThat(getLocation(value)).isEqualTo("7:7");
 	}
 
 	@Test
 	void getPropertyWithSeparatorInValue() {
-		OriginTrackedValue value = this.properties.get("bling");
+		OriginTrackedValue value = getFromFirst("bling");
 		assertThat(getValue(value)).isEqualTo("a=b");
 		assertThat(getLocation(value)).isEqualTo("8:9");
 	}
 
 	@Test
 	void getListProperty() {
-		OriginTrackedValue apple = this.properties.get("foods[0]");
+		OriginTrackedValue apple = getFromFirst("foods[0]");
 		assertThat(getValue(apple)).isEqualTo("Apple");
 		assertThat(getLocation(apple)).isEqualTo("24:9");
-		OriginTrackedValue orange = this.properties.get("foods[1]");
+		OriginTrackedValue orange = getFromFirst("foods[1]");
 		assertThat(getValue(orange)).isEqualTo("Orange");
 		assertThat(getLocation(orange)).isEqualTo("25:1");
-		OriginTrackedValue strawberry = this.properties.get("foods[2]");
+		OriginTrackedValue strawberry = getFromFirst("foods[2]");
 		assertThat(getValue(strawberry)).isEqualTo("Strawberry");
 		assertThat(getLocation(strawberry)).isEqualTo("26:1");
-		OriginTrackedValue mango = this.properties.get("foods[3]");
+		OriginTrackedValue mango = getFromFirst("foods[3]");
 		assertThat(getValue(mango)).isEqualTo("Mango");
 		assertThat(getLocation(mango)).isEqualTo("27:1");
 	}
 
 	@Test
 	void getPropertyWithISO88591Character() {
-		OriginTrackedValue value = this.properties.get("test-iso8859-1-chars");
+		OriginTrackedValue value = getFromFirst("test-iso8859-1-chars");
 		assertThat(getValue(value)).isEqualTo("æ×ÈÅÞßáñÀÿ");
 	}
 
 	@Test
 	void getPropertyWithTrailingSpace() {
-		OriginTrackedValue value = this.properties.get("test-with-trailing-space");
+		OriginTrackedValue value = getFromFirst("test-with-trailing-space");
 		assertThat(getValue(value)).isEqualTo("trailing ");
 	}
 
 	@Test
 	void getPropertyWithEscapedTrailingSpace() {
-		OriginTrackedValue value = this.properties.get("test-with-escaped-trailing-space");
+		OriginTrackedValue value = getFromFirst("test-with-escaped-trailing-space");
 		assertThat(getValue(value)).isEqualTo("trailing ");
 	}
 
+	private OriginTrackedValue getFromFirst(String key) {
+		return this.documentes.get(0).asMap().get(key);
+	}
+
 	private Object getValue(OriginTrackedValue value) {
 		return (value != null) ? value.getValue() : null;
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/env/PropertiesPropertySourceLoaderTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -48,6 +48,39 @@ class PropertiesPropertySourceLoaderTests {
 		assertThat(source.getProperty("test")).isEqualTo("properties");
 	}
 
+	@Test
+	void loadMultiDocumentPropertiesWithSeparatorAtTheBeginningofFile() throws Exception {
+		List<PropertySource<?>> loaded = this.loader.load("test.properties",
+				new ClassPathResource("multi-document-properties-2.properties", getClass()));
+		assertThat(loaded.size()).isEqualTo(2);
+		PropertySource<?> source1 = loaded.get(0);
+		PropertySource<?> source2 = loaded.get(1);
+		assertThat(source1.getProperty("blah")).isEqualTo("hello world");
+		assertThat(source2.getProperty("foo")).isEqualTo("bar");
+	}
+
+	@Test
+	void loadMultiDocumentProperties() throws Exception {
+		List<PropertySource<?>> loaded = this.loader.load("test.properties",
+				new ClassPathResource("multi-document-properties.properties", getClass()));
+		assertThat(loaded.size()).isEqualTo(2);
+		PropertySource<?> source1 = loaded.get(0);
+		PropertySource<?> source2 = loaded.get(1);
+		assertThat(source1.getProperty("blah")).isEqualTo("hello world");
+		assertThat(source2.getProperty("foo")).isEqualTo("bar");
+	}
+
+	@Test
+	void loadMultiDocumentPropertiesWithEmptyDocument() throws Exception {
+		List<PropertySource<?>> loaded = this.loader.load("test.properties",
+				new ClassPathResource("multi-document-properties-empty.properties", getClass()));
+		assertThat(loaded.size()).isEqualTo(2);
+		PropertySource<?> source1 = loaded.get(0);
+		PropertySource<?> source2 = loaded.get(1);
+		assertThat(source1.getProperty("blah")).isEqualTo("hello world");
+		assertThat(source2.getProperty("foo")).isEqualTo("bar");
+	}
+
 	@Test
 	void loadXml() throws Exception {
 		List<PropertySource<?>> loaded = this.loader.load("test.xml",

spring-boot-project/spring-boot/src/test/resources/org/springframework/boot/env/multi-document-properties-2.properties

+#---
+#test
+blah=hello world
+bar=baz
+hello=world
+#---
+foo=bar
+bling=biz
+#comment1
+#comment2
\ No newline at end of file

spring-boot-project/spring-boot/src/test/resources/org/springframework/boot/env/multi-document-properties-empty.properties

+
+#---
+#test
+blah=hello world
+bar=baz
+hello=world
+#---
+#---
+foo=bar
+bling=biz
+#comment1
+#comment2
\ No newline at end of file

spring-boot-project/spring-boot/src/test/resources/org/springframework/boot/env/multi-document-properties.properties

+#test
+blah=hello world
+bar=baz
+hello=world
+#---
+foo=bar
+bling=biz
+#comment1
+#comment2
+#---
\ No newline at end of file