Auto-generate the "Common application properties"

Prior to this commit, the application properties listed in the reference
documentation would be manually managed and updated.

This commit adds a new `spring-boot-configuration-docs` project that
extracts that information from the available JSON metadata and writes
Asciidoctor tables ready for inclusion in the reference documentation.

The `generateConfigurationPropertyTables.groovy` is using this library
and configures the sections and how namespaces should be organized.

Fixes gh-8237

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/main/java/org/springframework/boot/configurationdocs/AbstractConfigurationEntry.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import java.util.Objects;
+
+/**
+ * Abstract class for entries in {@link ConfigurationTable}.
+ *
+ * @author Brian Clozel
+ */
+abstract class AbstractConfigurationEntry
+		implements Comparable<AbstractConfigurationEntry> {
+
+	protected static final String NEWLINE = System.lineSeparator();
+
+	protected String key;
+
+	public String getKey() {
+		return this.key;
+	}
+
+	public abstract void writeAsciidoc(StringBuilder builder);
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+		AbstractConfigurationEntry that = (AbstractConfigurationEntry) o;
+		return this.key.equals(that.key);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(this.key);
+	}
+
+	@Override
+	public int compareTo(AbstractConfigurationEntry other) {
+		return this.key.compareTo(other.getKey());
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/main/java/org/springframework/boot/configurationdocs/CompoundKeyEntry.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.stream.Stream;
+
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataProperty;
+
+/**
+ * Table entry regrouping a list of configuration properties sharing the same description.
+ *
+ * @author Brian Clozel
+ */
+class CompoundKeyEntry extends AbstractConfigurationEntry {
+
+	private Set<String> configurationKeys;
+
+	private String description;
+
+	CompoundKeyEntry(String key, String description) {
+		this.key = key;
+		this.description = description;
+		this.configurationKeys = new TreeSet<>();
+	}
+
+	void addConfigurationKeys(ConfigurationMetadataProperty... properties) {
+		Stream.of(properties)
+				.forEach((property) -> this.configurationKeys.add(property.getId()));
+	}
+
+	@Override
+	public void writeAsciidoc(StringBuilder builder) {
+		builder.append("|`+++");
+		this.configurationKeys.forEach((key) -> builder.append(key).append(NEWLINE));
+		builder.append("+++`").append(NEWLINE).append("|").append(NEWLINE).append("|+++")
+				.append(this.description).append("+++").append(NEWLINE);
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/main/java/org/springframework/boot/configurationdocs/ConfigurationMetadataDocumentWriter.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataProperty;
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataRepository;
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataRepositoryJsonBuilder;
+
+/**
+ * Write Asciidoc documents with configuration properties listings.
+ *
+ * @author Brian Clozel
+ */
+public class ConfigurationMetadataDocumentWriter {
+
+	public void writeDocument(Path outputDirPath, DocumentOptions options,
+			InputStream... metadataInput) throws IOException {
+		if (outputDirPath == null) {
+			throw new IllegalArgumentException("output path should not be null");
+		}
+		if (Files.exists(outputDirPath) && !Files.isDirectory(outputDirPath)) {
+			throw new IllegalArgumentException(
+					"output path already exists and is not a directory");
+		}
+		else if (!Files.exists(outputDirPath)) {
+			Files.createDirectory(outputDirPath);
+		}
+		if (metadataInput == null || metadataInput.length < 1) {
+			throw new IllegalArgumentException("missing input metadata");
+		}
+
+		ConfigurationMetadataRepository configRepository = ConfigurationMetadataRepositoryJsonBuilder
+				.create(metadataInput).build();
+		Map<String, ConfigurationMetadataProperty> allProperties = configRepository
+				.getAllProperties();
+
+		List<ConfigurationTable> tables = createConfigTables(allProperties, options);
+
+		for (ConfigurationTable table : tables) {
+			Path outputFilePath = outputDirPath.resolve(table.getId() + ".adoc");
+			Files.deleteIfExists(outputFilePath);
+			Files.createFile(outputFilePath);
+			try (OutputStream outputStream = Files.newOutputStream(outputFilePath)) {
+				outputStream
+						.write(table.toAsciidocTable().getBytes(StandardCharsets.UTF_8));
+			}
+		}
+	}
+
+	private List<ConfigurationTable> createConfigTables(
+			Map<String, ConfigurationMetadataProperty> allProperties,
+			DocumentOptions options) {
+
+		final List<ConfigurationTable> tables = new ArrayList<>();
+		final List<String> unmappedKeys = allProperties.values().stream()
+				.filter((prop) -> !prop.isDeprecated()).map((prop) -> prop.getId())
+				.collect(Collectors.toList());
+
+		final Map<String, CompoundKeyEntry> overrides = getOverrides(allProperties,
+				unmappedKeys, options);
+
+		options.getMetadataSections().forEach((id, keyPrefixes) -> {
+			ConfigurationTable table = new ConfigurationTable(id);
+			tables.add(table);
+			for (String keyPrefix : keyPrefixes) {
+				List<String> matchingOverrides = overrides.keySet().stream()
+						.filter((overrideKey) -> overrideKey.startsWith(keyPrefix))
+						.collect(Collectors.toList());
+				matchingOverrides.forEach((match) -> {
+					table.addEntry(overrides.remove(match));
+				});
+			}
+			List<String> matchingKeys = unmappedKeys.stream()
+					.filter((key) -> keyPrefixes.stream().anyMatch(key::startsWith))
+					.collect(Collectors.toList());
+			for (String matchingKey : matchingKeys) {
+				ConfigurationMetadataProperty property = allProperties.get(matchingKey);
+				table.addEntry(new SingleKeyEntry(property));
+
+			}
+			unmappedKeys.removeAll(matchingKeys);
+		});
+
+		if (!unmappedKeys.isEmpty()) {
+			throw new IllegalStateException(
+					"The following keys were not written to the documentation: "
+							+ String.join(", ", unmappedKeys));
+		}
+		if (!overrides.isEmpty()) {
+			throw new IllegalStateException(
+					"The following keys  were not written to the documentation: "
+							+ String.join(", ", overrides.keySet()));
+		}
+
+		return tables;
+	}
+
+	private Map<String, CompoundKeyEntry> getOverrides(
+			Map<String, ConfigurationMetadataProperty> allProperties,
+			List<String> unmappedKeys, DocumentOptions options) {
+		final Map<String, CompoundKeyEntry> overrides = new HashMap<>();
+
+		options.getOverrides().forEach((keyPrefix, description) -> {
+			final CompoundKeyEntry entry = new CompoundKeyEntry(keyPrefix, description);
+			List<String> matchingKeys = unmappedKeys.stream()
+					.filter((key) -> key.startsWith(keyPrefix))
+					.collect(Collectors.toList());
+			for (String matchingKey : matchingKeys) {
+				entry.addConfigurationKeys(allProperties.get(matchingKey));
+			}
+			overrides.put(keyPrefix, entry);
+			unmappedKeys.removeAll(matchingKeys);
+		});
+		return overrides;
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/main/java/org/springframework/boot/configurationdocs/ConfigurationTable.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import java.util.Arrays;
+import java.util.Set;
+import java.util.TreeSet;
+
+/**
+ * Asciidoctor table listing configuration properties sharing to a common theme.
+ *
+ * @author Brian Clozel
+ */
+class ConfigurationTable {
+
+	private static final String NEWLINE = System.lineSeparator();
+
+	private final String id;
+
+	private final Set<AbstractConfigurationEntry> entries;
+
+	ConfigurationTable(String id) {
+		this.id = id;
+		this.entries = new TreeSet<>();
+	}
+
+	public String getId() {
+		return this.id;
+	}
+
+	void addEntry(AbstractConfigurationEntry... entries) {
+		this.entries.addAll(Arrays.asList(entries));
+	}
+
+	String toAsciidocTable() {
+		final StringBuilder builder = new StringBuilder();
+		builder.append("[cols=\"1,1,2\", options=\"header\"]").append(NEWLINE);
+		builder.append("|===").append(NEWLINE).append("|Key|Default Value|Description")
+				.append(NEWLINE).append(NEWLINE);
+		this.entries.forEach((entry) -> {
+			entry.writeAsciidoc(builder);
+			builder.append(NEWLINE);
+		});
+		return builder.append("|===").append(NEWLINE).toString();
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/main/java/org/springframework/boot/configurationdocs/DocumentOptions.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Options for generating documentation for configuration properties.
+ *
+ * @author Brian Clozel
+ */
+public final class DocumentOptions {
+
+	private final Map<String, List<String>> metadataSections;
+
+	private final Map<String, String> overrides;
+
+	private DocumentOptions(Map<String, List<String>> metadataSections,
+			Map<String, String> overrides) {
+		this.metadataSections = metadataSections;
+		this.overrides = overrides;
+	}
+
+	Map<String, List<String>> getMetadataSections() {
+		return this.metadataSections;
+	}
+
+	Map<String, String> getOverrides() {
+		return this.overrides;
+	}
+
+	static Builder builder() {
+		return new Builder();
+	}
+
+	/**
+	 * Builder for DocumentOptions.
+	 */
+	public static class Builder {
+
+		Map<String, List<String>> metadataSections = new HashMap<>();
+
+		Map<String, String> overrides = new HashMap<>();
+
+		SectionSpec addSection(String name) {
+			return new SectionSpec(this, name);
+		}
+
+		Builder addOverride(String keyPrefix, String description) {
+			this.overrides.put(keyPrefix, description);
+			return this;
+		}
+
+		DocumentOptions build() {
+			return new DocumentOptions(this.metadataSections, this.overrides);
+		}
+
+	}
+
+	/**
+	 * Configuration for a documentation section listing properties for a specific theme.
+	 */
+	public static class SectionSpec {
+
+		private final String name;
+
+		private final Builder builder;
+
+		SectionSpec(Builder builder, String name) {
+			this.builder = builder;
+			this.name = name;
+		}
+
+		Builder withKeyPrefixes(String... keyPrefixes) {
+			this.builder.metadataSections.put(this.name, Arrays.asList(keyPrefixes));
+			return this.builder;
+		}
+
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/main/java/org/springframework/boot/configurationdocs/SingleKeyEntry.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import java.util.Arrays;
+import java.util.stream.Collectors;
+
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataProperty;
+
+/**
+ * Table entry containing a single configuration property.
+ *
+ * @author Brian Clozel
+ */
+class SingleKeyEntry extends AbstractConfigurationEntry {
+
+	private String defaultValue;
+
+	private String description;
+
+	SingleKeyEntry(ConfigurationMetadataProperty property) {
+
+		this.key = property.getId();
+		if (property.getType() != null
+				&& property.getType().startsWith("java.util.Map")) {
+			this.key += ".*";
+		}
+
+		this.description = property.getDescription();
+
+		if (property.getDefaultValue() != null) {
+			if (property.getDefaultValue().getClass().isArray()) {
+				this.defaultValue = Arrays.stream((Object[]) property.getDefaultValue())
+						.map(Object::toString).collect(Collectors.joining("," + NEWLINE));
+			}
+			else {
+				this.defaultValue = property.getDefaultValue().toString();
+			}
+		}
+	}
+
+	@Override
+	public void writeAsciidoc(StringBuilder builder) {
+		builder.append("|`+").append(this.key).append("+`").append(NEWLINE);
+		String defaultValue = processDefaultValue();
+		if (defaultValue.length() > 0) {
+			builder.append("|`+").append(defaultValue).append("+`").append(NEWLINE);
+		}
+		else {
+			builder.append("|").append(NEWLINE);
+		}
+		if (this.description != null) {
+			builder.append("|+++").append(this.description).append("+++");
+		}
+		else {
+			builder.append("|");
+		}
+		builder.append(NEWLINE);
+	}
+
+	private String processDefaultValue() {
+		if (this.defaultValue != null && this.defaultValue.length() > 0) {
+			return this.defaultValue.replace("\\", "\\\\").replace("|",
+					"{vbar}" + NEWLINE);
+		}
+		return "";
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/test/java/org/springframework/boot/configurationdocs/CompoundKeyEntryTests.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import org.junit.Test;
+
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataProperty;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Brian Clozel
+ */
+public class CompoundKeyEntryTests {
+
+	private static String NEWLINE = System.lineSeparator();
+
+	@Test
+	public void simpleProperty() {
+		ConfigurationMetadataProperty firstProp = new ConfigurationMetadataProperty();
+		firstProp.setId("spring.test.first");
+		firstProp.setType("java.lang.String");
+
+		ConfigurationMetadataProperty secondProp = new ConfigurationMetadataProperty();
+		secondProp.setId("spring.test.second");
+		secondProp.setType("java.lang.String");
+
+		ConfigurationMetadataProperty thirdProp = new ConfigurationMetadataProperty();
+		thirdProp.setId("spring.test.third");
+		thirdProp.setType("java.lang.String");
+
+		CompoundKeyEntry entry = new CompoundKeyEntry("spring.test",
+				"This is a description.");
+		entry.addConfigurationKeys(firstProp, secondProp, thirdProp);
+		StringBuilder builder = new StringBuilder();
+		entry.writeAsciidoc(builder);
+
+		assertThat(builder.toString()).isEqualTo("|`+++spring.test.first" + NEWLINE
+				+ "spring.test.second" + NEWLINE + "spring.test.third" + NEWLINE + "+++`"
+				+ NEWLINE + "|" + NEWLINE + "|+++This is a description.+++" + NEWLINE);
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/test/java/org/springframework/boot/configurationdocs/ConfigurationTableTests.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import org.junit.Test;
+
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataProperty;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Brian Clozel
+ */
+public class ConfigurationTableTests {
+
+	private static String NEWLINE = System.lineSeparator();
+
+	@Test
+	public void simpleTable() {
+		ConfigurationTable table = new ConfigurationTable("test");
+
+		ConfigurationMetadataProperty first = new ConfigurationMetadataProperty();
+		first.setId("spring.test.prop");
+		first.setDefaultValue("something");
+		first.setDescription("This is a description.");
+		first.setType("java.lang.String");
+
+		ConfigurationMetadataProperty second = new ConfigurationMetadataProperty();
+		second.setId("spring.test.other");
+		second.setDefaultValue("other value");
+		second.setDescription("This is another description.");
+		second.setType("java.lang.String");
+
+		table.addEntry(new SingleKeyEntry(first));
+		table.addEntry(new SingleKeyEntry(second));
+
+		assertThat(table.toAsciidocTable())
+				.isEqualTo("[cols=\"1,1,2\", options=\"header\"]" + NEWLINE + "|==="
+						+ NEWLINE + "|Key|Default Value|Description" + NEWLINE + NEWLINE
+						+ "|`+spring.test.other+`" + NEWLINE + "|`+other value+`"
+						+ NEWLINE + "|+++This is another description.+++" + NEWLINE
+						+ NEWLINE + "|`+spring.test.prop+`" + NEWLINE + "|`+something+`"
+						+ NEWLINE + "|+++This is a description.+++" + NEWLINE + NEWLINE
+						+ "|===" + NEWLINE);
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-configuration-docs/src/test/java/org/springframework/boot/configurationdocs/SingleKeyEntryTests.java

@@ -0,0 +1,130 @@
+/*
+ * Copyright 2012-2019 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.configurationdocs;
+
+import org.junit.Test;
+
+import org.springframework.boot.configurationmetadata.ConfigurationMetadataProperty;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Brian Clozel
+ */
+public class SingleKeyEntryTests {
+
+	private static String NEWLINE = System.lineSeparator();
+
+	@Test
+	public void simpleProperty() {
+		ConfigurationMetadataProperty property = new ConfigurationMetadataProperty();
+		property.setId("spring.test.prop");
+		property.setDefaultValue("something");
+		property.setDescription("This is a description.");
+		property.setType("java.lang.String");
+
+		SingleKeyEntry entry = new SingleKeyEntry(property);
+		StringBuilder builder = new StringBuilder();
+		entry.writeAsciidoc(builder);
+
+		assertThat(builder.toString()).isEqualTo("|`+spring.test.prop+`" + NEWLINE
+				+ "|`+something+`" + NEWLINE + "|+++This is a description.+++" + NEWLINE);
+	}
+
+	@Test
+	public void noDefaultValue() {
+		ConfigurationMetadataProperty property = new ConfigurationMetadataProperty();
+		property.setId("spring.test.prop");
+		property.setDescription("This is a description.");
+		property.setType("java.lang.String");
+
+		SingleKeyEntry entry = new SingleKeyEntry(property);
+		StringBuilder builder = new StringBuilder();
+		entry.writeAsciidoc(builder);
+
+		assertThat(builder.toString()).isEqualTo("|`+spring.test.prop+`" + NEWLINE + "|"
+				+ NEWLINE + "|+++This is a description.+++" + NEWLINE);
+	}
+
+	@Test
+	public void defaultValueWithPipes() {
+		ConfigurationMetadataProperty property = new ConfigurationMetadataProperty();
+		property.setId("spring.test.prop");
+		property.setDefaultValue("first|second");
+		property.setDescription("This is a description.");
+		property.setType("java.lang.String");
+
+		SingleKeyEntry entry = new SingleKeyEntry(property);
+		StringBuilder builder = new StringBuilder();
+		entry.writeAsciidoc(builder);
+
+		assertThat(builder.toString()).isEqualTo("|`+spring.test.prop+`" + NEWLINE
+				+ "|`+first{vbar}" + NEWLINE + "second+`" + NEWLINE
+				+ "|+++This is a description.+++" + NEWLINE);
+	}
+
+	@Test
+	public void defaultValueWithBackslash() {
+		ConfigurationMetadataProperty property = new ConfigurationMetadataProperty();
+		property.setId("spring.test.prop");
+		property.setDefaultValue("first\\second");
+		property.setDescription("This is a description.");
+		property.setType("java.lang.String");
+
+		SingleKeyEntry entry = new SingleKeyEntry(property);
+		StringBuilder builder = new StringBuilder();
+		entry.writeAsciidoc(builder);
+
+		assertThat(builder.toString())
+				.isEqualTo("|`+spring.test.prop+`" + NEWLINE + "|`+first\\\\second+`"
+						+ NEWLINE + "|+++This is a description.+++" + NEWLINE);
+	}
+
+	@Test
+	public void mapProperty() {
+		ConfigurationMetadataProperty property = new ConfigurationMetadataProperty();
+		property.setId("spring.test.prop");
+		property.setDescription("This is a description.");
+		property.setType("java.util.Map<java.lang.String,java.lang.String>");
+
+		SingleKeyEntry entry = new SingleKeyEntry(property);
+		StringBuilder builder = new StringBuilder();
+		entry.writeAsciidoc(builder);
+
+		assertThat(builder.toString()).isEqualTo("|`+spring.test.prop.*+`" + NEWLINE + "|"
+				+ NEWLINE + "|+++This is a description.+++" + NEWLINE);
+	}
+
+	@Test
+	public void listProperty() {
+		String[] defaultValue = new String[] { "first", "second", "third" };
+		ConfigurationMetadataProperty property = new ConfigurationMetadataProperty();
+		property.setId("spring.test.prop");
+		property.setDescription("This is a description.");
+		property.setType("java.util.List<java.lang.String>");
+		property.setDefaultValue(defaultValue);
+
+		SingleKeyEntry entry = new SingleKeyEntry(property);
+		StringBuilder builder = new StringBuilder();
+		entry.writeAsciidoc(builder);
+
+		assertThat(builder.toString()).isEqualTo("|`+spring.test.prop+`" + NEWLINE
+				+ "|`+first," + NEWLINE + "second," + NEWLINE + "third+`" + NEWLINE
+				+ "|+++This is a description.+++" + NEWLINE);
+	}
+
+}