diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/CompletionUtils.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/CompletionUtils.java
index 60f139ef32..39247d4592 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/CompletionUtils.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/CompletionUtils.java
@@ -43,10 +43,11 @@ public static String sanitizeCompletion(String replace) {
 	 *            the completion itemDefaults of the completion list
 	 */
 	public static void setInsertTextMode(final CompletionItem item, CompletionItemDefaults completionItemDefaults) {
-		if ((!JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionListItemDefaultsPropertySupport("insertTextMode") ||
+		var clientPreferences = JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences();
+		if ((!clientPreferences.isCompletionListItemDefaultsPropertySupport("insertTextMode") ||
 				completionItemDefaults.getInsertTextMode() == null ||
 				completionItemDefaults.getInsertTextMode() != InsertTextMode.AdjustIndentation) &&
-				JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().getCompletionItemInsertTextModeDefault() != InsertTextMode.AdjustIndentation
+				clientPreferences.getCompletionItemInsertTextModeDefault() != InsertTextMode.AdjustIndentation
 		) {
 			item.setInsertTextMode(InsertTextMode.AdjustIndentation);
 		}
@@ -61,8 +62,9 @@ public static void setInsertTextMode(final CompletionItem item, CompletionItemDe
 	 *            the completion itemDefaults of the completion list
 	 */
 	public static void setInsertTextFormat(final CompletionItem item, CompletionItemDefaults completionItemDefaults) {
-		InsertTextFormat insertTextFormat = JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionSnippetsSupported() ? InsertTextFormat.Snippet : InsertTextFormat.PlainText;
-		if (!JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionListItemDefaultsPropertySupport("insertTextFormat") ||
+		var clientPreferences = JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences();
+		InsertTextFormat insertTextFormat = clientPreferences.isCompletionSnippetsSupported() ? InsertTextFormat.Snippet : InsertTextFormat.PlainText;
+		if (!clientPreferences.isCompletionListItemDefaultsPropertySupport("insertTextFormat") ||
 			completionItemDefaults.getInsertTextFormat() == null ||
 			completionItemDefaults.getInsertTextFormat() != insertTextFormat
 		) {
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalDescriptionProvider.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalDescriptionProvider.java
index 83c70c890a..5315d61611 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalDescriptionProvider.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalDescriptionProvider.java
@@ -839,6 +839,7 @@ private void setLabelDetails(CompletionItem item, String label, String detail, S
 	}
 
 	private boolean isCompletionItemLabelDetailsSupport() {
-		return JavaLanguageServerPlugin.getPreferencesManager() != null && JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionItemLabelDetailsSupport();
+		var preferenceManager = JavaLanguageServerPlugin.getPreferencesManager();
+		return preferenceManager != null && preferenceManager.getClientPreferences().isCompletionItemLabelDetailsSupport();
 	}
 }
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalReplacementProvider.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalReplacementProvider.java
index fa3913e051..0f434f42e8 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalReplacementProvider.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalReplacementProvider.java
@@ -176,8 +176,8 @@ public void updateReplacement(CompletionProposal proposal, CompletionItem item,
 		} else {
 			item.setInsertTextFormat(InsertTextFormat.PlainText);
 		}
-		if (isResolvingRequest || (!JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionListItemDefaultsPropertySupport("insertTextMode")
-				&& JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().getCompletionItemInsertTextModeDefault() != InsertTextMode.AdjustIndentation)) {
+		if (isResolvingRequest || (!client.isCompletionListItemDefaultsPropertySupport("insertTextMode")
+				&& client.getCompletionItemInsertTextModeDefault() != InsertTextMode.AdjustIndentation)) {
 			item.setInsertTextMode(InsertTextMode.AdjustIndentation);
 		}
 
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalRequestor.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalRequestor.java
index eaa2157bf9..5c8e5da86f 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalRequestor.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/CompletionProposalRequestor.java
@@ -260,17 +260,16 @@ public List<CompletionItem> getCompletionItems() {
 
 	public List<CompletionItem> getCompletionItems(IProgressMonitor monitor) {
 		CompletionRankingAggregation[] aggregatedRanks = getAggregatedRankingResult(monitor);
+		Map<CompletionProposal, CompletionRankingAggregation> proposalToRankingResult = new HashMap<>(proposals.size());
 		for (int i = 0; i < proposals.size(); i++) {
 			CompletionProposal proposal = proposals.get(i);
-			if (aggregatedRanks[i] != null) {
+			CompletionRankingAggregation ranking = aggregatedRanks[i];
+			if (ranking != null) {
 				// we assume there won't be overflow for now since the the score from
 				// each provider can only be 100 at most.
-				proposal.setRelevance(proposal.getRelevance() + aggregatedRanks[i].getScore());
+				proposal.setRelevance(proposal.getRelevance() + ranking.getScore());
 			}
-		}
-		Map<CompletionProposal, CompletionRankingAggregation> proposalToRankingResult = new HashMap<>();
-		for (int i = 0; i < proposals.size(); i++) {
-			proposalToRankingResult.put(proposals.get(i), aggregatedRanks[i]);
+			proposalToRankingResult.put(proposal, ranking);
 		}
 
 		proposals.sort(new ProposalComparator(proposals.size()));
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/JavadocCompletionProposal.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/JavadocCompletionProposal.java
index 0dc2d19b6d..6564b5b1cd 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/JavadocCompletionProposal.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/JavadocCompletionProposal.java
@@ -107,10 +107,11 @@ public List<CompletionItem> getProposals(ICompilationUnit cu, int offset, Comple
 			}
 			final CompletionItem ci = new CompletionItem();
 			CompletionItemDefaults completionItemDefaults = collector.getCompletionItemDefaults();
+			var clientPreferences = JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences();
 			Range range = JDTUtils.toRange(unit, offset, 0);
-			boolean isSnippetSupported = JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionSnippetsSupported();
+			boolean isSnippetSupported = clientPreferences.isCompletionSnippetsSupported();
 			String replacement = prepareTemplate(buf.toString(), lineDelimiter, isSnippetSupported);
-			if (JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionListItemDefaultsPropertySupport("editRange") &&
+			if (clientPreferences.isCompletionListItemDefaultsPropertySupport("editRange") &&
 				completionItemDefaults != null && completionItemDefaults.getEditRange() != null &&
 				completionItemDefaults.getEditRange().getLeft() == range) {
 				ci.setTextEditText(replacement);
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetCompletionProposal.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetCompletionProposal.java
index 88546a6470..c04e58dc39 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetCompletionProposal.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetCompletionProposal.java
@@ -431,7 +431,8 @@ public static void setTextEdit(CompletionContext completionContext, ICompilation
 	}
 
 	private static boolean isCompletionItemLabelDetailsSupport() {
-		return JavaLanguageServerPlugin.getPreferencesManager() != null && JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isCompletionItemLabelDetailsSupport();
+		var preferenceManager = JavaLanguageServerPlugin.getPreferencesManager();
+		return preferenceManager != null && preferenceManager.getClientPreferences().isCompletionItemLabelDetailsSupport();
 	}
 
 	public static String evaluateGenericTemplate(ICompilationUnit cu, CompletionContext completionContext, Template template) {
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetUtils.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetUtils.java
index c6b0a47e5e..f5e363dd60 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetUtils.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/contentassist/SnippetUtils.java
@@ -83,8 +83,9 @@ public static Either<String, MarkupContent> beautifyDocument(String raw) {
 		escapedString = escapedString.replaceAll(TM_SELECTED_TEXT, "");
 		escapedString = escapedString.replaceAll(TM_FILENAME_BASE, "");
 
-		if (JavaLanguageServerPlugin.getPreferencesManager() != null && JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences() != null
-				&& JavaLanguageServerPlugin.getPreferencesManager().getClientPreferences().isSupportsCompletionDocumentationMarkdown()) {
+		var preferenceManager = JavaLanguageServerPlugin.getPreferencesManager();
+		if (preferenceManager != null && preferenceManager.getClientPreferences() != null
+				&& preferenceManager.getClientPreferences().isSupportsCompletionDocumentationMarkdown()) {
 			MarkupContent markupContent = new MarkupContent();
 			markupContent.setKind(MarkupKind.MARKDOWN);
 			markupContent.setValue(String.format("```%s\n%s\n```", MARKDOWN_LANGUAGE, escapedString));
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/CompletionHandler.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/CompletionHandler.java
index 4a6172ebdb..a4bd89efdf 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/CompletionHandler.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/handlers/CompletionHandler.java
@@ -140,17 +140,18 @@ public Either<List<CompletionItem>, CompletionList> completion(CompletionParams
 		long executionTime = System.currentTimeMillis() - startTime;
 		String lastRequestId = null;
 		for (CompletionItem item : $.getItems()) {
-			String requestId = "";
-			String proposalId = "";
 			@SuppressWarnings("unchecked")
 			Map<String, String> data = (Map<String, String>) item.getData();
-			if (data != null) {
-				requestId = data.getOrDefault(CompletionResolveHandler.DATA_FIELD_REQUEST_ID, "");
-				proposalId = data.getOrDefault(CompletionResolveHandler.DATA_FIELD_PROPOSAL_ID, "");
+			if (data == null) {
+				continue;
 			}
-			if (requestId.isEmpty() || proposalId.isEmpty()) {
+
+			String requestId = data.get(CompletionResolveHandler.DATA_FIELD_REQUEST_ID);
+			String proposalId = data.get(CompletionResolveHandler.DATA_FIELD_PROPOSAL_ID);
+			if (requestId == null || requestId.isEmpty() || proposalId == null || proposalId.isEmpty()) {
 				continue;
 			}
+
 			item.setCommand(new Command("", "java.completion.onDidSelect", Arrays.asList(
 					requestId,
 					proposalId