Yaml<->Props conversion commands, tests, integration in VSCode, Eclipse

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/app/BootLanguageServerInitializer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2018, 2023 Pivotal, Inc.
+ * Copyright (c) 2018, 2024 Pivotal, Inc.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -129,7 +129,7 @@ public class BootLanguageServerInitializer implements InitializingBean {
 			builder.add(c);	
 		}
 		
-		components = builder.build(server);
+		components = builder.build(appContext);
 		
 		final SimpleTextDocumentService documents = server.getTextDocumentService();
 

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/properties/BootPropertiesLanguageServerComponents.java

@@ -105,7 +105,12 @@ public class BootPropertiesLanguageServerComponents implements LanguageServerCom
 				});
 			});
 		});
-
+		
+		// Register YAML -> Props conversion command
+		new YamlToPropertiesCommand(server);
+		
+		// Register Props -> YAML conversion command
+		new PropertiesToYamlCommand(server);
 	}
 
 	@Override

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/properties/PropertiesToYamlCommand.java

@@ -0,0 +1,124 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Broadcom, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Broadcom, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.boot.properties;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.net.URI;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.regex.Pattern;
+
+import org.eclipse.lsp4j.ApplyWorkspaceEditParams;
+import org.eclipse.lsp4j.ShowDocumentParams;
+import org.eclipse.lsp4j.ShowDocumentResult;
+import org.eclipse.lsp4j.WorkspaceEdit;
+import org.springframework.ide.vscode.commons.languageserver.util.SimpleLanguageServer;
+import org.springframework.ide.vscode.commons.util.BadLocationException;
+import org.springframework.ide.vscode.commons.util.text.LanguageId;
+import org.springframework.ide.vscode.commons.util.text.LazyTextDocument;
+import org.springframework.ide.vscode.commons.util.text.TextDocument;
+
+import com.google.common.collect.Multimap;
+import com.google.common.collect.Multimaps;
+import com.google.gson.JsonElement;
+import com.google.gson.internal.LinkedTreeMap;
+
+public class PropertiesToYamlCommand {
+
+	static final String CMD_PROPS_TO_YAML = "sts/boot/props-to-yaml";
+	
+	private static final Pattern COMMENT = Pattern.compile("(?m)^\\s*(\\#|\\!)");
+	
+	private final SimpleLanguageServer server;
+	
+	PropertiesToYamlCommand(SimpleLanguageServer server) {
+		this.server = server;
+		server.onCommand(CMD_PROPS_TO_YAML, params -> execute(params.getArguments()));
+	}
+
+	private CompletableFuture<ShowDocumentResult> execute(List<Object> arguments) {
+		String propsUri = arguments.get(0) instanceof JsonElement ? ((JsonElement) arguments.get(0)).getAsString() : (String) arguments.get(0);
+		String yamlUri = arguments.get(1) instanceof JsonElement ? ((JsonElement) arguments.get(1)).getAsString() : (String) arguments.get(1);
+		Boolean replace = arguments.get(2) instanceof JsonElement ? ((JsonElement) arguments.get(2)).getAsBoolean() : (Boolean) arguments.get(2);
+		return CompletableFuture.supplyAsync(() -> {
+			try {
+				return createWorkspaceEdit(propsUri, yamlUri, replace);
+			} catch (IOException | BadLocationException e) {
+				throw new CompletionException(e);
+			}
+		})
+		.thenCompose(we -> server.getClient().applyEdit(new ApplyWorkspaceEditParams(we, "Convert .properties to .yaml")))
+		.thenCompose(res -> res.isApplied() ? server.getClient().showDocument(new ShowDocumentParams(yamlUri)) : CompletableFuture.completedFuture(new ShowDocumentResult(false)));
+	}
+
+	private WorkspaceEdit createWorkspaceEdit(String propsUri, String yamlUri, Boolean replace) throws IOException, BadLocationException {
+		Path yamlFile = Paths.get(URI.create(yamlUri));
+		if (Files.exists(yamlFile)) {
+			throw new IOException("File %s already exists!".formatted(yamlFile.toString()));
+		}
+		
+		TextDocument doc = getDocument(propsUri, LanguageId.BOOT_PROPERTIES);
+		String propsContent = doc.get();
+		List<String> errors = new ArrayList<>();
+		List<String> warnings = new ArrayList<>();
+			
+		if (hasComments(propsContent)) {
+			warnings.add("The yaml file had comments which are lost in the refactoring!");
+		}
+		
+		Multimap<String, String> properties = load(new StringReader(propsContent));
+		PropertiesToYamlConverter converter = new PropertiesToYamlConverter(properties);
+		
+		StringBuilder yamlContent = new StringBuilder();
+		errors.addAll(converter.getErrors());
+		warnings.addAll(converter.getWarnings());
+		YamlToPropertiesCommand.addReportHeaderComment(yamlContent, errors, warnings);
+		yamlContent.append(converter.getYaml());
+		
+		return replace ? YamlToPropertiesCommand.createReplaceFileWorkspaceEdit(propsUri, yamlUri, doc, yamlContent.toString()) : YamlToPropertiesCommand.createNewFileWorkspaceEdit(yamlUri, yamlContent.toString());
+	}
+	
+	private Multimap<String, String> load(Reader content) throws IOException {
+		Multimap<String, String> map = Multimaps.newMultimap(
+				new LinkedTreeMap<String, Collection<String>>(), 
+				LinkedHashSet::new
+		);
+		Properties loader = new Properties() {
+			private static final long serialVersionUID = 1L;
+			public synchronized Object put(Object key, Object value) {
+				map.put((String)key, (String)value);
+				return super.put(key, value);
+			}
+		};
+		loader.load(content);
+		return map;
+	}
+	
+	private static boolean hasComments(String propsContent) {
+		return COMMENT.matcher(propsContent).find();
+	}
+	
+	private TextDocument getDocument(String uri, LanguageId language) {
+		TextDocument doc = server.getTextDocumentService().getLatestSnapshot(uri);
+		return doc == null ? new LazyTextDocument(uri, language) : doc;
+	}
+
+}

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/properties/PropertiesToYamlConverter.java

@@ -0,0 +1,184 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Broadcom, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Broadcom, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.boot.properties;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.stream.Collectors;
+
+import org.eclipse.core.runtime.Assert;
+import org.springframework.ide.vscode.commons.yaml.path.YamlPath;
+import org.springframework.ide.vscode.commons.yaml.path.YamlPathSegment;
+import org.springframework.ide.vscode.commons.yaml.path.YamlPathSegment.AtIndex;
+import org.yaml.snakeyaml.DumperOptions;
+import org.yaml.snakeyaml.LoaderOptions;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.constructor.SafeConstructor;
+import org.yaml.snakeyaml.representer.Representer;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.Multimap;
+import com.google.gson.internal.LinkedTreeMap;
+
+/**
+ * Helper class to convert (Spring Boot) .properties file content into equivalent
+ * .yml file content.
+ *
+ * @author Kris De Volder
+ */
+class PropertiesToYamlConverter {
+
+	private String output;
+	private ImmutableList.Builder<String> errors;
+	private ImmutableList.Builder<String> warnings;
+
+	class YamlBuilder {
+		final YamlPath path;
+		final List<Object> scalars = new ArrayList<>();
+		final LinkedTreeMap<Integer, YamlBuilder> listItems = new LinkedTreeMap<>();
+		final LinkedTreeMap<String, YamlBuilder> mapEntries = new LinkedTreeMap<>();
+
+		public YamlBuilder(YamlPath path) {
+			this.path = path;
+		}
+
+		void addProperty(YamlPath path, String value) {
+			if (path.isEmpty()) {
+				scalars.add(objectify(value));
+			} else {
+				YamlPathSegment segment = path.getSegment(0);
+				YamlBuilder subBuilder;
+				if (segment instanceof AtIndex) {
+					subBuilder = getSubBuilder(listItems, segment, segment.toIndex());
+				} else {
+					subBuilder = getSubBuilder(mapEntries, segment, segment.toPropString());
+				}
+				subBuilder.addProperty(path.dropFirst(1), value);
+			}
+		}
+
+		private Object objectify(String value) {
+			if (value != null) {
+				Object parsed = null;
+				try {
+					parsed = new BigInteger(value);
+				} catch (NumberFormatException e) {
+					try {
+						parsed = new BigDecimal(value);
+					} catch (NumberFormatException e2) {
+						if (value.equals("true")) {
+							parsed = true;
+						} else if (value.equals("false")) {
+							parsed = false;
+						}
+					}
+				}
+				if (parsed!=null && parsed.toString().equals(value)) {
+					return parsed;
+				}
+			}
+			return value;
+		}
+
+		private <T> YamlBuilder getSubBuilder(LinkedTreeMap<T, YamlBuilder> subBuilders, YamlPathSegment segment, T key) {
+			YamlBuilder existing = subBuilders.get(key);
+			if (existing==null) {
+				subBuilders.put(key, existing = new YamlBuilder(path.append(segment)));
+			}
+			return existing;
+		}
+
+		public Object build() {
+			if (!scalars.isEmpty()) {
+				if (listItems.isEmpty() && mapEntries.isEmpty()) {
+					if (scalars.size()>1) {
+						warnings.add("Multiple values "+ scalars +" assigned to '"+path.toPropString()+"'. Values are merged into a yaml sequence node.");
+						return scalars;
+					} else {
+						return scalars.get(0);
+					}
+				} else {
+					if (!mapEntries.isEmpty()) {
+						errors.add(
+								"Direct assignment '"+path.toPropString()+"="+scalars.get(0)+"' can not be combined " +
+								"with sub-property assignment '"+path.toPropString()+"." + mapEntries.keySet().iterator().next()+"...'. "+
+								"Direct assignment is dropped!"
+						);
+					} else {
+						errors.add(
+								"Direct assignment '"+path.toPropString()+"="+scalars.get(0)+"' can not be combined " +
+								"with sequence assignment '"+path.toPropString()+"[" + listItems.keySet().iterator().next()+"]...'. "+
+								"Direct assignments are dropped!"
+						);
+					}
+					scalars.clear();
+				}
+			}
+			Assert.isLegal(scalars.isEmpty());
+			if (!listItems.isEmpty() && !mapEntries.isEmpty()) {
+				warnings.add("'"+path.toPropString()+"' has some entries that look like list items and others that look like map entries. "
+						+ "All these entries are treated as map entries!");
+				for (Entry<Integer, YamlBuilder> listItem : listItems.entrySet()) {
+					mapEntries.put(listItem.getKey().toString(), listItem.getValue());
+				}
+				listItems.clear();
+			}
+			if (!listItems.isEmpty()) {
+				return listItems.values().stream()
+					.map(childBuilder -> childBuilder.build())
+					.collect(Collectors.toList());
+			} else {
+				LinkedTreeMap<String, Object> map = new LinkedTreeMap<>();
+				for (Entry<String, YamlBuilder> entry : mapEntries.entrySet()) {
+					map.put(entry.getKey(), entry.getValue().build());
+				}
+				return map;
+			}
+		}
+	}
+
+	public PropertiesToYamlConverter(Multimap<String, String> properties) {
+		this.errors = ImmutableList.builder();
+		this.warnings = ImmutableList.builder();
+		if (properties.isEmpty()) {
+			output = "";
+			return;
+		}
+		YamlBuilder root = new YamlBuilder(YamlPath.EMPTY);
+		for (Entry<String, String> e : properties.entries()) {
+			root.addProperty(YamlPath.fromProperty(e.getKey()), e.getValue());
+		}
+		Object object = root.build();
+
+		DumperOptions options = new DumperOptions();
+		options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
+		options.setPrettyFlow(true);
+
+		Yaml yaml = new Yaml(new SafeConstructor(new LoaderOptions()), new Representer(options), options);
+		this.output = yaml.dump(object);
+	}
+
+	public List<String> getErrors() {
+		return errors.build();
+	}
+	
+	public List<String> getWarnings() {
+		return warnings.build();
+	}
+
+	public String getYaml() {
+		return output;
+	}
+
+}

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/properties/YamlToPropertiesCommand.java

@@ -0,0 +1,204 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Broadcom, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Broadcom, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.boot.properties;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.net.URI;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.UUID;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+
+import org.eclipse.lsp4j.AnnotatedTextEdit;
+import org.eclipse.lsp4j.ApplyWorkspaceEditParams;
+import org.eclipse.lsp4j.ChangeAnnotation;
+import org.eclipse.lsp4j.CreateFile;
+import org.eclipse.lsp4j.Position;
+import org.eclipse.lsp4j.Range;
+import org.eclipse.lsp4j.RenameFile;
+import org.eclipse.lsp4j.ShowDocumentParams;
+import org.eclipse.lsp4j.ShowDocumentResult;
+import org.eclipse.lsp4j.TextDocumentEdit;
+import org.eclipse.lsp4j.VersionedTextDocumentIdentifier;
+import org.eclipse.lsp4j.WorkspaceEdit;
+import org.eclipse.lsp4j.jsonrpc.messages.Either;
+import org.springframework.ide.vscode.commons.languageserver.util.SimpleLanguageServer;
+import org.springframework.ide.vscode.commons.util.BadLocationException;
+import org.springframework.ide.vscode.commons.util.text.LanguageId;
+import org.springframework.ide.vscode.commons.util.text.LazyTextDocument;
+import org.springframework.ide.vscode.commons.util.text.TextDocument;
+import org.yaml.snakeyaml.LoaderOptions;
+import org.yaml.snakeyaml.Yaml;
+import org.yaml.snakeyaml.comments.CommentType;
+import org.yaml.snakeyaml.events.CommentEvent;
+import org.yaml.snakeyaml.events.Event;
+
+import com.google.gson.JsonElement;
+
+class YamlToPropertiesCommand {
+	
+	private static final String LABEL = "Convert .yaml to .properties";
+
+	static final String CMD_YAML_TO_PROPS = "sts/boot/yaml-to-props";
+	
+	private final SimpleLanguageServer server;
+	
+	YamlToPropertiesCommand(SimpleLanguageServer server) {
+		this.server = server;
+		server.onCommand(CMD_YAML_TO_PROPS, params -> execute(params.getArguments()));
+	}
+	
+	private CompletableFuture<ShowDocumentResult> execute(List<Object> arguments) {
+		String yamlUri = arguments.get(0) instanceof JsonElement ? ((JsonElement) arguments.get(0)).getAsString() : (String) arguments.get(0);
+		String propsUri = arguments.get(1) instanceof JsonElement ? ((JsonElement) arguments.get(1)).getAsString() : (String) arguments.get(1);
+		Boolean replace = arguments.get(2) instanceof JsonElement ? ((JsonElement) arguments.get(2)).getAsBoolean() : (Boolean) arguments.get(2);
+		return CompletableFuture.supplyAsync(() -> {
+			try {
+				return createWorkspaceEdit(yamlUri, propsUri, replace);
+			} catch (IOException | BadLocationException e) {
+				throw new CompletionException(e);
+			}
+		})
+		.thenCompose(we -> server.getClient().applyEdit(new ApplyWorkspaceEditParams(we, LABEL)))
+		.thenCompose(res -> res.isApplied() ? server.getClient().showDocument(new ShowDocumentParams(propsUri)) : CompletableFuture.completedFuture(new ShowDocumentResult(false)));
+	}
+
+	private WorkspaceEdit createWorkspaceEdit(String yamlUri, String propsUri, boolean replace) throws IOException, BadLocationException {
+		Path propsFile = Paths.get(URI.create(propsUri));
+		if (Files.exists(propsFile)) {
+			throw new IOException("File %s already exists!".formatted(propsFile.toString()));
+		}
+		
+		List<String> errors = new ArrayList<>();
+		List<String> warnings = new ArrayList<>();
+		TextDocument doc = getDocument(server, yamlUri, LanguageId.BOOT_PROPERTIES_YAML);
+		String yamlContent = doc.get();
+			
+		if (hasComments(yamlContent)) {
+			warnings.add("The yaml file had comments which are lost in the refactoring!");
+		}
+			
+		StringBuilder propsContent = new StringBuilder();
+		for (Object d : new Yaml().loadAll(new StringReader(yamlContent))) {
+			if (d instanceof Map) {
+				// Add doc divider if not empty
+				@SuppressWarnings("unchecked")
+				Map<String, ?> o = (Map<String, ?>) d;
+				YamlToPropertiesConverter converter = new YamlToPropertiesConverter(o);
+				Properties props = converter.getProperties();
+				StringWriter write = new StringWriter();
+				props.store(write, null);
+				if (!propsContent.isEmpty()) {
+					propsContent.append("#---\n");
+				} else {
+					addReportHeaderComment(propsContent, errors, warnings);
+				}
+				// Skip over the date header. Comments are not present but date header is.
+				if (write.getBuffer().charAt(0) == '#') {
+					int idx = write.getBuffer().indexOf("\n");
+					propsContent.append(idx >= 0 && idx < write.getBuffer().length() ? write.getBuffer().substring(idx + 1) : write.getBuffer().toString());
+				} else {
+					propsContent.append(write.getBuffer().toString());
+				}
+			} else if (d == null) {
+				if (!propsContent.isEmpty()) {
+					propsContent.append("#---\n");
+				}
+			}
+		}
+		
+		return replace ? createReplaceFileWorkspaceEdit(yamlUri, propsUri, doc, propsContent.toString()) : createNewFileWorkspaceEdit(propsUri, propsContent.toString());
+	}
+
+	
+	private static boolean hasComments(String yamlContent) {
+		LoaderOptions loaderOptions = new LoaderOptions();
+		loaderOptions.setProcessComments(true);
+		for (Event e : new Yaml(loaderOptions).parse(new StringReader(yamlContent))) {
+			if (e instanceof CommentEvent ce) {
+				if (ce.getCommentType() == CommentType.BLANK_LINE) {
+					// document separator
+				} else {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+	
+	static WorkspaceEdit createReplaceFileWorkspaceEdit(String sourceUri, String targetUri, TextDocument oldDoc, String newContent) throws BadLocationException {
+		String changeAnnotationId = UUID.randomUUID().toString();
+		ChangeAnnotation changeAnnotation = new ChangeAnnotation(LABEL);
+		changeAnnotation.setNeedsConfirmation(true);
+		
+		RenameFile renameFile = new RenameFile(sourceUri, targetUri);
+		renameFile.setAnnotationId(changeAnnotationId);
+		WorkspaceEdit we = new WorkspaceEdit(List.of(
+				Either.forLeft(new TextDocumentEdit(
+						new VersionedTextDocumentIdentifier(sourceUri, oldDoc.getVersion()),
+						List.of(new AnnotatedTextEdit(oldDoc.toRange(0, oldDoc.getLength()), newContent, changeAnnotationId))
+				)),
+				Either.forRight(renameFile)
+		));
+		we.setChangeAnnotations(Map.of(changeAnnotationId, changeAnnotation));
+		return we;
+	}
+	
+	static WorkspaceEdit createNewFileWorkspaceEdit(String uri, String content) {
+		String changeAnnotationId = UUID.randomUUID().toString();
+		ChangeAnnotation changeAnnotation = new ChangeAnnotation(LABEL);
+		changeAnnotation.setNeedsConfirmation(false); // VSCode refactor preview errors out showing diff for newly added file
+		
+		CreateFile createFile = new CreateFile(uri);
+		createFile.setAnnotationId(changeAnnotationId);
+		WorkspaceEdit we = new WorkspaceEdit(List.of(
+				Either.forRight(createFile),
+				Either.forLeft(new TextDocumentEdit(
+						new VersionedTextDocumentIdentifier(uri, null),
+						List.of(new AnnotatedTextEdit(new Range(new Position(0,0), new Position(0,0)), content, changeAnnotationId))
+				))
+		));
+		we.setChangeAnnotations(Map.of(changeAnnotationId, changeAnnotation));
+		return we;
+	}
+	
+	static TextDocument getDocument(SimpleLanguageServer server, String uri, LanguageId language) {
+		TextDocument doc = server.getTextDocumentService().getLatestSnapshot(uri);
+		return doc == null ? new LazyTextDocument(uri, language) : doc;
+	}
+	
+	static void addReportHeaderComment(StringBuilder content, List<String> errors, List<String> warnings) {
+		if (!errors.isEmpty() || !warnings.isEmpty()) {
+			content.append("# Conversion to YAML from Properties formar report\n");
+			if (!errors.isEmpty()) {
+				content.append("# Errors:\n");
+				for (String e : errors) {
+					content.append("# - %s\n".formatted(e));
+				}
+			}
+			if (!warnings.isEmpty()) {
+				content.append("# Warnings:\n");
+				for (String w : warnings) {
+					content.append("# - %s\n".formatted(w));
+				}
+			}
+		}
+	}
+
+}

headless-services/spring-boot-language-server/src/main/java/org/springframework/ide/vscode/boot/properties/YamlToPropertiesConverter.java

@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Broadcom, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Broadcom, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.boot.properties;
+
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+
+class YamlToPropertiesConverter {
+
+	private final Properties properties;
+
+
+	public YamlToPropertiesConverter(Map<String, ?> yaml) {
+		this.properties = new Properties() {
+
+			private static final long serialVersionUID = 1L;
+
+			private LinkedHashMap<Object, Object> delegate = new LinkedHashMap<>();
+
+			@Override
+			public synchronized Object put(Object key, Object value) {
+				delegate.put(key, value);
+				return super.put(key, value);
+			}
+
+			@Override
+			public Set<Map.Entry<Object, Object>> entrySet() {
+				return delegate.entrySet();
+			}
+
+		};
+
+		for (Map.Entry<String, ?> e : yaml.entrySet()) {
+			readProperties(e.getValue(), e.getKey());
+		}
+	}
+
+	private void readPropertiesFromYamlMap(Map<String, ?> map, String prefix) {
+		for (Map.Entry<String, ?> e : map.entrySet()) {
+			readProperties(e.getValue(), "%s.%s".formatted(prefix, e.getKey()));
+		}
+	}
+
+	private void readPropertiesFromYamlList(List<?> l, String prefix) {
+		for (int i = 0; i < l.size(); i++) {
+			readProperties(l.get(i), "%s[%d]".formatted(prefix, i));
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	private void readProperties(Object o, String prefix) {
+		if (o instanceof Map) {
+			readPropertiesFromYamlMap((Map<String, ?>) o, prefix);
+		} else if ( o instanceof List) {
+			readPropertiesFromYamlList((List<?>) o, prefix);
+		} else {
+			properties.put(prefix, o.toString());
+		}
+	}
+
+	public Properties getProperties() {
+		return properties;
+	}
+
+}

headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/properties/PropertiesToYamlCommandTest.java

@@ -0,0 +1,313 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Broadcom, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Broadcom, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.boot.properties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.List;
+
+import org.eclipse.lsp4j.Command;
+import org.eclipse.lsp4j.ShowDocumentResult;
+import org.eclipse.lsp4j.TextDocumentIdentifier;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Import;
+import org.springframework.ide.vscode.boot.bootiful.BootLanguageServerTest;
+import org.springframework.ide.vscode.boot.bootiful.SymbolProviderTestConf;
+import org.springframework.ide.vscode.commons.languageserver.java.JavaProjectFinder;
+import org.springframework.ide.vscode.languageserver.testharness.LanguageServerHarness;
+import org.springframework.ide.vscode.project.harness.ProjectsHarness;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@BootLanguageServerTest
+@Import({SymbolProviderTestConf.class})
+public class PropertiesToYamlCommandTest {
+
+	private static final String FILENAME_SUFFIX = "-conversion-test";
+	
+	@Autowired private LanguageServerHarness harness;
+	@Autowired private JavaProjectFinder projectFinder;
+	
+	private File directory;
+
+	@BeforeEach public void setup() throws Exception {
+		harness.intialize(null);
+		
+		directory = new File(ProjectsHarness.class.getResource("/test-projects/test-spring-validations/").toURI());
+		
+		Files.walk(directory.toPath(), Integer.MAX_VALUE).filter(Files::isRegularFile).filter(p -> p.getFileName().toString().contains(FILENAME_SUFFIX)).forEach(t -> {
+			try {
+				Files.delete(t);
+			} catch (IOException e) {
+				
+			}
+		});
+
+		String projectDir = directory.toURI().toString();
+
+		// trigger project creation
+		projectFinder.find(new TextDocumentIdentifier(projectDir)).get();
+	}
+	
+	@AfterEach public void tearDown() throws Exception {
+		if (directory != null && directory.exists()) {
+			Files.walk(directory.toPath(), Integer.MAX_VALUE).filter(Files::isRegularFile).filter(p -> p.getFileName().toString().contains(FILENAME_SUFFIX)).forEach(t -> {
+				try {
+					Files.delete(t);
+				} catch (IOException e) {
+					
+				}
+			});
+		}
+	}
+
+	void assertConversion(String propsContent, String yamlContent, boolean replace) throws Exception {
+		Path yamlFilePath = directory.toPath().resolve("src/main/resources/application" + FILENAME_SUFFIX + ".yml");
+		Path propsFilePath = directory.toPath().resolve("src/main/resources/application" + FILENAME_SUFFIX + ".properties");
+		
+		if (!Files.exists(propsFilePath)) {
+			Files.createDirectories(propsFilePath.getParent());
+			Files.createFile(propsFilePath);
+			Files.write(propsFilePath, propsContent.getBytes(), StandardOpenOption.APPEND);
+		}
+		
+		Command cmd = new Command();
+		cmd.setCommand(PropertiesToYamlCommand.CMD_PROPS_TO_YAML);
+		cmd.setArguments(List.of(propsFilePath.toUri().toASCIIString(), yamlFilePath.toUri().toASCIIString(), replace));
+		cmd.setTitle("Convert .propeties to .yaml");
+		
+		ShowDocumentResult res = (ShowDocumentResult) harness.perform(cmd);
+		
+		assertThat(res.isSuccess()).isTrue();
+		
+		assertThat(Files.exists(yamlFilePath)).isTrue();
+		if (replace) {
+			assertThat(Files.exists(propsFilePath)).isFalse();
+		} else {
+			assertThat(Files.exists(propsFilePath)).isTrue();
+		}
+		
+		assertThat(Files.readString(yamlFilePath)).isEqualTo(yamlContent);
+	}
+	
+	@Test void almostHasComments() throws Exception {
+		assertConversion(
+			"my.hello=Good morning!\n" +
+			"my.goodbye=See ya # later\n"
+			, // ==>
+			"my:\n" +
+			"  hello: Good morning!\n" +
+			"  goodbye: 'See ya # later'\n",
+			true
+		);
+	}
+
+
+	@Test void listItems() throws Exception {
+		assertConversion(
+				"some.thing[0].a=first-a\n" +
+				"some.thing[0].b=first-b\n" +
+				"some.thing[1].a=second-a\n" +
+				"some.thing[1].b=second-b\n"
+				, // ==>
+				"some:\n" +
+				"  thing:\n" +
+				"  - a: first-a\n" +
+				"    b: first-b\n" +
+				"  - a: second-a\n" +
+				"    b: second-b\n",
+				true
+		);
+	}
+
+	@Test void simple() throws Exception {
+		assertConversion(
+				"some.thing=vvvv\n" +
+				"some.other.thing=blah\n"
+				, // ==>
+				"some:\n" +
+				"  thing: vvvv\n" +
+				"  other:\n" +
+				"    thing: blah\n",
+				true
+		);
+	}
+
+	@Test void noReplacement() throws Exception {
+		assertConversion(
+				"some.thing=vvvv\n" +
+				"some.other.thing=blah\n"
+				, // ==>
+				"some:\n" +
+				"  thing: vvvv\n" +
+				"  other:\n" +
+				"    thing: blah\n",
+				false
+		);
+	}
+	
+	@Test void nonStringyValueConversion() throws Exception {
+		//See: https://www.pivotaltracker.com/story/show/154181583
+		//Test that we do not add unnecessary quotes around certain types of values.
+		assertConversion(
+				"exponated=123.4E-12\n" +
+				"server.port=8888\n" +
+				"foobar.enabled=true\n" +
+				"foobar.nice=false\n" +
+				"fractional=0.78\n" +
+				"largenumber=989898989898989898989898989898989898989898989898989898989898\n" +
+				"longfractional=-0.989898989898989898989898989898989898989898989898989898989898\n"
+				, // ==>
+				"exponated: '123.4E-12'\n" + //quotes are added because conversion to number changes the string value
+				"server:\n" +
+				"  port: 8888\n" +
+				"foobar:\n" +
+				"  enabled: true\n" +
+				"  nice: false\n" +
+				"fractional: 0.78\n" +
+				"largenumber: 989898989898989898989898989898989898989898989898989898989898\n" +
+				"longfractional: -0.989898989898989898989898989898989898989898989898989898989898\n",
+				true
+		);
+	}
+
+	@Test void emptyFileConversion() throws Exception {
+		assertConversion(
+				""
+				, // ==>
+				"",
+				true
+		);
+	}
+
+	@Test void multipleAssignmentProblem() throws Exception {
+		assertConversion(
+				"some.property=something\n" +
+				"some.property=something-else"
+				, // ==>
+				"# Conversion to YAML from Properties formar report\n" +
+				"# Warnings:\n" +
+				"# - Multiple values [something, something-else] assigned to 'some.property'. Values are merged into a yaml sequence node.\n" +
+				"some:\n" +
+				"  property:\n" +
+				"  - something\n" +
+				"  - something-else\n"
+ 				,
+ 				true
+		);
+	}
+
+	@Test void scalarAndMapConflict() throws Exception {
+		assertConversion(
+				"some.property=a-scalar\n" +
+				"some.property.sub=sub-value"
+				,
+				"# Conversion to YAML from Properties formar report\n" +
+				"# Errors:\n" +
+				"# - Direct assignment 'some.property=a-scalar' can not be combined with sub-property assignment 'some.property.sub...'. Direct assignment is dropped!\n" +
+				"some:\n" +
+				"  property:\n" +
+				"    sub: sub-value\n"
+				,
+				true
+		);
+	}
+
+	@Test void scalarAndSequenceConflict() throws Exception {
+		assertConversion(
+				"some.property=a-scalar\n" +
+				"some.property[0]=zero\n" +
+				"some.property[1]=one\n"
+				,
+				"# Conversion to YAML from Properties formar report\n" +
+				"# Errors:\n" +
+				"# - Direct assignment 'some.property=a-scalar' can not be combined with sequence assignment 'some.property[0]...'. Direct assignments are dropped!\n" +
+				"some:\n" +
+				"  property:\n" +
+				"  - zero\n" +
+				"  - one\n"
+				,
+				true
+		);
+	}
+
+	@Test public void mapAndSequenceConflict() throws Exception {
+		assertConversion(
+				"some.property.abc=val1\n" +
+				"some.property.def=val2\n" +
+				"some.property[0]=zero\n" +
+				"some.property[1]=one\n"
+				,
+				"# Conversion to YAML from Properties formar report\n" +
+				"# Warnings:\n" +
+				"# - 'some.property' has some entries that look like list items and others that look like map entries. All these entries are treated as map entries!\n" +
+				"some:\n" +
+				"  property:\n" +
+				"    abc: val1\n" +
+				"    def: val2\n" +
+				"    '0': zero\n" +
+				"    '1': one\n"
+				,
+				true
+		);
+	}
+
+	@Test public void scalarAndMapAndSequenceConflict() throws Exception {
+		assertConversion(
+				"some.property=a-scalar\n" +
+				"some.property.abc=val1\n" +
+				"some.property.def=val2\n" +
+				"some.property[0]=zero\n" +
+				"some.property[1]=one\n"
+				,
+				"# Conversion to YAML from Properties formar report\n" +
+				"# Errors:\n" +
+				"# - Direct assignment 'some.property=a-scalar' can not be combined with sub-property assignment 'some.property.abc...'. Direct assignment is dropped!\n" +
+				"# Warnings:\n" +
+				"# - 'some.property' has some entries that look like list items and others that look like map entries. All these entries are treated as map entries!\n" +
+				"some:\n" +
+				"  property:\n" +
+				"    abc: val1\n" +
+				"    def: val2\n" +
+				"    '0': zero\n" +
+				"    '1': one\n"
+				,
+				true
+		);
+	}
+	
+	@Test void lineComment() throws Exception {
+		assertConversion(
+				"some.thing=vvvv\n" +
+				"# Line comment\n" +
+				"some.other.thing=blah\n"
+				, // ==>
+				"# Conversion to YAML from Properties formar report\n" +
+				"# Warnings:\n" +
+				"# - The yaml file had comments which are lost in the refactoring!\n" +
+				"some:\n" +
+				"  thing: vvvv\n" +
+				"  other:\n" +
+				"    thing: blah\n",
+				true
+		);
+	}
+
+}

headless-services/spring-boot-language-server/src/test/java/org/springframework/ide/vscode/boot/properties/YamlToPropertiesCommandTest.java

@@ -0,0 +1,263 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Broadcom, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Broadcom, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.springframework.ide.vscode.boot.properties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.List;
+
+import org.eclipse.lsp4j.Command;
+import org.eclipse.lsp4j.ShowDocumentResult;
+import org.eclipse.lsp4j.TextDocumentIdentifier;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Import;
+import org.springframework.ide.vscode.boot.bootiful.BootLanguageServerTest;
+import org.springframework.ide.vscode.boot.bootiful.SymbolProviderTestConf;
+import org.springframework.ide.vscode.commons.languageserver.java.JavaProjectFinder;
+import org.springframework.ide.vscode.languageserver.testharness.LanguageServerHarness;
+import org.springframework.ide.vscode.project.harness.ProjectsHarness;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+@ExtendWith(SpringExtension.class)
+@BootLanguageServerTest
+@Import({SymbolProviderTestConf.class})
+public class YamlToPropertiesCommandTest {
+	
+	private static final String FILENAME_SUFFIX = "-conversion-test";
+	
+	@Autowired private LanguageServerHarness harness;
+	@Autowired private JavaProjectFinder projectFinder;
+	
+	private File directory;
+
+	@BeforeEach public void setup() throws Exception {
+		harness.intialize(null);
+		
+		directory = new File(ProjectsHarness.class.getResource("/test-projects/test-spring-validations/").toURI());
+		
+		Files.walk(directory.toPath(), Integer.MAX_VALUE).filter(Files::isRegularFile).filter(p -> p.getFileName().toString().contains(FILENAME_SUFFIX)).forEach(t -> {
+			try {
+				Files.delete(t);
+			} catch (IOException e) {
+				
+			}
+		});
+
+		String projectDir = directory.toURI().toString();
+
+		// trigger project creation
+		projectFinder.find(new TextDocumentIdentifier(projectDir)).get();
+	}
+	
+	@AfterEach public void tearDown() throws Exception {
+		if (directory != null && directory.exists()) {
+			Files.walk(directory.toPath(), Integer.MAX_VALUE).filter(Files::isRegularFile).filter(p -> p.getFileName().toString().contains(FILENAME_SUFFIX)).forEach(t -> {
+				try {
+					Files.delete(t);
+				} catch (IOException e) {
+					
+				}
+			});
+		}
+	}
+
+	@Test void simple() throws Exception {
+		assertConversion("""
+				some:
+				  other:
+				    thing: blah
+				  thing: vvvv
+				""",
+				"""
+				some.other.thing=blah
+				some.thing=vvvv		
+				""",
+				true);
+	}
+	
+	@Test void noReplacement() throws Exception {		
+		assertConversion("""
+				some:
+				  other:
+				    thing: blah
+				  thing: vvvv
+				""",
+				"""
+				some.other.thing=blah
+				some.thing=vvvv		
+				""",
+				false);
+	}
+	
+	@Test public void almostHasComments() throws Exception {
+		assertConversion(
+			"my:\n" +
+			"  goodbye: 'See ya # later'\n" +
+			"  hello: Good morning!\n"
+			, // ==>
+			"my.goodbye=See ya \\# later\n" +
+			"my.hello=Good morning\\!\n",
+			true
+		);
+	}
+	
+	@Test public void listItems() throws Exception {
+		assertConversion(
+				"some:\n" +
+				"  thing:\n" +
+				"  - a: first-a\n" +
+				"    b: first-b\n" +
+				"  - a: second-a\n" +
+				"    b: second-b\n"
+				, // ==>
+				"some.thing[0].a=first-a\n" +
+				"some.thing[0].b=first-b\n" +
+				"some.thing[1].a=second-a\n" +
+				"some.thing[1].b=second-b\n",
+				true
+		);
+	}
+
+	@Test public void list() throws Exception {
+		assertConversion(
+				"some:\n" +
+				"  property:\n" +
+				"  - something\n" +
+				"  - something-else\n"
+				, // ==>
+				"some.property[0]=something\n" +
+				"some.property[1]=something-else\n",
+				true
+		);
+	}
+
+	@Test public void mapAndSequenceConflict() throws Exception {
+		assertConversion(
+				"some:\n" +
+				"  property:\n" +
+				"    '0': zero\n" +
+				"    '1': one\n" +
+				"    abc: val1\n" +
+				"    def: val2\n"
+				,
+				"some.property.0=zero\n" +
+				"some.property.1=one\n" +
+				"some.property.abc=val1\n" +
+				"some.property.def=val2\n",
+				true
+		);
+	}
+
+	@Test public void multipleDocsConversion() throws Exception {
+		assertConversion(
+				"some:\n" +
+				"  other:\n" +
+				"    thing: blah\n" +
+				"  thing: vvvv\n" +
+				"\n" +
+				"---\n" +
+				"some:\n" +
+				"  other:\n" +
+				"    thing: blah\n" +
+				"  thing: vvvv\n" +
+				"\n" +
+				"---\n" +
+				"some:\n" +
+				"  other:\n" +
+				"    thing: blah\n" +
+				"  thing: vvvv\n"
+				, // ==>
+				"some.other.thing=blah\n" +
+				"some.thing=vvvv\n" +
+				"#---\n" +
+				"some.other.thing=blah\n" +
+				"some.thing=vvvv\n" +
+				"#---\n" +
+				"some.other.thing=blah\n" +
+				"some.thing=vvvv\n",
+				true
+		);
+	}
+
+	@Test void lineComment() throws Exception {
+		assertConversion("""
+				some:
+				  # Comment about line	
+				  other:
+				    thing: blah
+				  thing: vvvv
+				""",
+				"""
+				# Conversion to YAML from Properties formar report
+				# Warnings:
+				# - The yaml file had comments which are lost in the refactoring!
+				some.other.thing=blah
+				some.thing=vvvv		
+				""",
+				true);
+	}
+
+	@Test void inlineComment() throws Exception {
+		assertConversion("""
+				some:	
+				  other:
+				    thing: blah # Inline Comment
+				  thing: vvvv
+				""",
+				"""
+				# Conversion to YAML from Properties formar report
+				# Warnings:
+				# - The yaml file had comments which are lost in the refactoring!
+				some.other.thing=blah
+				some.thing=vvvv		
+				""",
+				true);
+	}
+	
+	void assertConversion(String yamlContent, String propsContent, boolean replace) throws Exception {
+		Path yamlFilePath = directory.toPath().resolve("src/main/resources/application" + FILENAME_SUFFIX + ".yml");
+		Path propsFilePath = directory.toPath().resolve("src/main/resources/application" + FILENAME_SUFFIX + ".properties");
+		
+		if (!Files.exists(yamlFilePath)) {
+			Files.createDirectories(yamlFilePath.getParent());
+			Files.createFile(yamlFilePath);
+			Files.write(yamlFilePath, yamlContent.getBytes(), StandardOpenOption.APPEND);
+		}
+		
+		Command cmd = new Command();
+		cmd.setCommand(YamlToPropertiesCommand.CMD_YAML_TO_PROPS);
+		cmd.setArguments(List.of(yamlFilePath.toUri().toASCIIString(), propsFilePath.toUri().toASCIIString(), replace));
+		cmd.setTitle("Convert .yaml to .properties");
+		
+		ShowDocumentResult res = (ShowDocumentResult) harness.perform(cmd);
+		
+		assertThat(res.isSuccess()).isTrue();
+		
+		assertThat(Files.exists(propsFilePath)).isTrue();
+		if (replace) {
+			assertThat(Files.exists(yamlFilePath)).isFalse();
+		} else {
+			assertThat(Files.exists(yamlFilePath)).isTrue();
+		}
+		
+		assertThat(Files.readString(propsFilePath)).isEqualTo(propsContent);
+	}
+
+}