The Java debug pane is not expanding the keys in a HashMap

[apoorv-gupta]

Problem: HashMap nodes are unexpandable when a Map.Entry local variable exists (screenshot attached)

Sample code

package com.tech.maven;

import java.util.HashMap;
import java.util.Map;

public class Bug {
    public static void main(String[] args) {
        Map<String, String> m = new HashMap<>();
        m.put("employees", "500");
        m.put("department", "IT");

        // Put your breakpoint on the line below  ←←←←←
        System.out.println("breakpoint here");

        // After you stop here, look at "m" in VARIABLES or WATCH → m.entrySet()
        // You will see only one entry (or unexpandable nodes) if the bug is still present
    }
    
}

VScode & Extensions Environment

JavaSE 17 (Temurin)

Version: 1.106.3
Commit: bf9252a2fb45be6893dd8870c0bf37e2e1766d61
Date: 2025-11-25T22:28:18.024Z (3 days ago)
Electron: 37.7.0
ElectronBuildId: 12781156
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Darwin arm64 24.5.0

{
message: "Use the JDK from 'java.jdt.ls.java.home' setting as the initial default project JDK.",
level: 'info',
timestamp: '2025-11-28 17:42:36.098'
}
{
message: 'Starting Java server with: /Library/Java/JavaVirtualMachines/temurin-25.jdk/Contents/Home/bin/java -Djdk.xml.maxGeneralEntitySizeLimit=0 -Djdk.xml.totalEntitySizeLimit=0 --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -DDetectVMInstallationsJob.disabled=true -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx2G -Xms100m -Xlog:disable -javaagent:/Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/lombok/lombok-1.18.39-4050.jar -jar /Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/server/plugins/org.eclipse.equinox.launcher_1.7.100.v20251111-0406.jar -configuration /Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_ss_mac -data /Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java/ss_ws',
level: 'info',
timestamp: '2025-11-28 17:42:36.104'
}
{
message: 'WARNING: Using incubator modules: jdk.incubator.vector\n',
level: 'info',
timestamp: '2025-11-28 17:42:36.168'
}
{
message: 'Starting Java server with: /Library/Java/JavaVirtualMachines/temurin-25.jdk/Contents/Home/bin/java -Djdk.xml.maxGeneralEntitySizeLimit=0 -Djdk.xml.totalEntitySizeLimit=0 --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -DDetectVMInstallationsJob.disabled=true -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx2G -Xms100m -Xlog:disable -javaagent:/Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/lombok/lombok-1.18.39-4050.jar -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java -Daether.dependencyCollector.impl=bf -jar /Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/server/plugins/org.eclipse.equinox.launcher_1.7.100.v20251111-0406.jar -configuration /Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_mac -data /Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java/jdt_ws',
level: 'info',
timestamp: '2025-11-28 17:42:36.184'
}
{
message: 'WARNING: Using incubator modules: jdk.incubator.vector\n',
level: 'info',
timestamp: '2025-11-28 17:42:36.215'
}
{
message: 'An error has occurred. See the log file\n' +
'/Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_ss_mac/1764369756291.log.\n',
level: 'info',
timestamp: '2025-11-28 17:42:36.549'
}
{
message: 'Nov 28, 2025 5:42:36 PM org.apache.aries.spifly.BaseActivator log\n' +
'INFO: Registered provider ch.qos.logback.classic.spi.LogbackServiceProvider of service org.slf4j.spi.SLF4JServiceProvider in bundle ch.qos.logback.classic\n',
level: 'info',
timestamp: '2025-11-28 17:42:36.642'
}
{
message: 'WARNING: A terminally deprecated method in sun.misc.Unsafe has been called\n' +
'WARNING: sun.misc.Unsafe::staticFieldBase has been called by com.google.inject.internal.aop.HiddenClassDefiner (file:/Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_mac/org.eclipse.osgi/69/0/.cp/jars/guice-5.1.0-classes.jar)\n' +
'WARNING: Please consider reporting this to the maintainers of class com.google.inject.internal.aop.HiddenClassDefiner\n' +
'WARNING: sun.misc.Unsafe::staticFieldBase will be removed in a future release\n',
level: 'info',
timestamp: '2025-11-28 17:42:37.400'
}
{
message: 'Nov 28, 2025 5:42:39 PM com.microsoft.java.debug.plugin.internal.JavaDebuggerServerPlugin start\n' +
'INFO: Starting com.microsoft.java.debug.plugin\n',
level: 'info',
timestamp: '2025-11-28 17:42:39.985'
}
{
message: 'Nov 28, 2025 5:42:44 PM com.microsoft.java.debug.core.UsageDataSession recordInfo\n' +
'INFO: launch debug info\n',
level: 'info',
timestamp: '2025-11-28 17:42:44.149'
}
{
message: 'Nov 28, 2025 5:42:49 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:42:49.363'
}
{
message: 'Nov 28, 2025 5:42:56 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:42:56.376'
}
{
message: 'Nov 28, 2025 5:45:18 PM com.microsoft.java.debug.core.UsageDataSession submitUsageData\n' +
'INFO: session usage data summary\n',
level: 'info',
timestamp: '2025-11-28 17:45:18.373'
}
{
message: "Use the JDK from 'java.jdt.ls.java.home' setting as the initial default project JDK.",
level: 'info',
timestamp: '2025-11-28 17:45:50.541'
}
{
message: 'Starting Java server with: /Library/Java/JavaVirtualMachines/temurin-25.jdk/Contents/Home/bin/java -Djdk.xml.maxGeneralEntitySizeLimit=0 -Djdk.xml.totalEntitySizeLimit=0 --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -DDetectVMInstallationsJob.disabled=true -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx2G -Xms100m -Xlog:disable -javaagent:/Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/lombok/lombok-1.18.39-4050.jar -jar /Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/server/plugins/org.eclipse.equinox.launcher_1.7.100.v20251111-0406.jar -configuration /Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_ss_mac -data /Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java/ss_ws',
level: 'info',
timestamp: '2025-11-28 17:45:50.546'
}
{
message: 'WARNING: Using incubator modules: jdk.incubator.vector\n',
level: 'info',
timestamp: '2025-11-28 17:45:50.601'
}
{
message: 'Starting Java server with: /Library/Java/JavaVirtualMachines/temurin-25.jdk/Contents/Home/bin/java -Djdk.xml.maxGeneralEntitySizeLimit=0 -Djdk.xml.totalEntitySizeLimit=0 --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -DDetectVMInstallationsJob.disabled=true -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx2G -Xms100m -Xlog:disable -javaagent:/Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/lombok/lombok-1.18.39-4050.jar -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java -Daether.dependencyCollector.impl=bf -jar /Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/server/plugins/org.eclipse.equinox.launcher_1.7.100.v20251111-0406.jar -configuration /Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_mac -data /Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java/jdt_ws',
level: 'info',
timestamp: '2025-11-28 17:45:50.604'
}
{
message: 'WARNING: Using incubator modules: jdk.incubator.vector\n',
level: 'info',
timestamp: '2025-11-28 17:45:50.634'
}
{
message: 'Nov 28, 2025 5:45:50 PM org.apache.aries.spifly.BaseActivator log\n' +
'INFO: Registered provider ch.qos.logback.classic.spi.LogbackServiceProvider of service org.slf4j.spi.SLF4JServiceProvider in bundle ch.qos.logback.classic\n',
level: 'info',
timestamp: '2025-11-28 17:45:50.916'
}
{
message: 'WARNING: A terminally deprecated method in sun.misc.Unsafe has been called\n' +
'WARNING: sun.misc.Unsafe::objectFieldOffset has been called by lombok.permit.Permit\n' +
'WARNING: Please consider reporting this to the maintainers of class lombok.permit.Permit\n' +
'WARNING: sun.misc.Unsafe::objectFieldOffset will be removed in a future release\n',
level: 'info',
timestamp: '2025-11-28 17:45:51.738'
}
{
message: 'WARNING: A terminally deprecated method in sun.misc.Unsafe has been called\n' +
'WARNING: sun.misc.Unsafe::staticFieldBase has been called by com.google.inject.internal.aop.HiddenClassDefiner (file:/Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_mac/org.eclipse.osgi/69/0/.cp/jars/guice-5.1.0-classes.jar)\n' +
'WARNING: Please consider reporting this to the maintainers of class com.google.inject.internal.aop.HiddenClassDefiner\n' +
'WARNING: sun.misc.Unsafe::staticFieldBase will be removed in a future release\n',
level: 'info',
timestamp: '2025-11-28 17:45:51.766'
}
{
message: 'Nov 28, 2025 5:45:52 PM com.microsoft.java.debug.plugin.internal.JavaDebuggerServerPlugin start\n' +
'INFO: Starting com.microsoft.java.debug.plugin\n',
level: 'info',
timestamp: '2025-11-28 17:45:52.628'
}
{
message: 'Nov 28, 2025 5:46:03 PM com.microsoft.java.debug.core.UsageDataSession recordInfo\n' +
'INFO: launch debug info\n',
level: 'info',
timestamp: '2025-11-28 17:46:03.267'
}
{
message: 'Nov 28, 2025 5:46:08 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:46:08.487'
}
{
message: "Use the JDK from 'java.jdt.ls.java.home' setting as the initial default project JDK.",
level: 'info',
timestamp: '2025-11-28 17:48:27.353'
}
{
message: 'Starting Java server with: /Library/Java/JavaVirtualMachines/temurin-25.jdk/Contents/Home/bin/java -Djdk.xml.maxGeneralEntitySizeLimit=0 -Djdk.xml.totalEntitySizeLimit=0 --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -DDetectVMInstallationsJob.disabled=true -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx2G -Xms100m -Xlog:disable -javaagent:/Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/lombok/lombok-1.18.39-4050.jar -jar /Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/server/plugins/org.eclipse.equinox.launcher_1.7.100.v20251111-0406.jar -configuration /Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_ss_mac -data /Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java/ss_ws',
level: 'info',
timestamp: '2025-11-28 17:48:27.358'
}
{
message: 'WARNING: Using incubator modules: jdk.incubator.vector\n',
level: 'info',
timestamp: '2025-11-28 17:48:27.404'
}
{
message: 'Starting Java server with: /Library/Java/JavaVirtualMachines/temurin-25.jdk/Contents/Home/bin/java -Djdk.xml.maxGeneralEntitySizeLimit=0 -Djdk.xml.totalEntitySizeLimit=0 --add-modules=ALL-SYSTEM --add-opens java.base/java.util=ALL-UNNAMED --add-opens java.base/java.lang=ALL-UNNAMED --add-opens java.base/sun.nio.fs=ALL-UNNAMED -Declipse.application=org.eclipse.jdt.ls.core.id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Djava.import.generatesMetadataFilesAtProjectRoot=false -DDetectVMInstallationsJob.disabled=true -Dfile.encoding=utf8 -XX:+UseParallelGC -XX:GCTimeRatio=4 -XX:AdaptiveSizePolicyWeight=90 -Dsun.zip.disableMemoryMapping=true -Xmx2G -Xms100m -Xlog:disable -javaagent:/Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/lombok/lombok-1.18.39-4050.jar -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java -Daether.dependencyCollector.impl=bf -jar /Users/apoorvgupta/.vscode/extensions/redhat.java-1.50.0-darwin-arm64/server/plugins/org.eclipse.equinox.launcher_1.7.100.v20251111-0406.jar -configuration /Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_mac -data /Users/apoorvgupta/Library/Application Support/Code/User/workspaceStorage/165590fa5fdbeda64cc12900062709b0/redhat.java/jdt_ws',
level: 'info',
timestamp: '2025-11-28 17:48:27.420'
}
{
message: 'WARNING: Using incubator modules: jdk.incubator.vector\n',
level: 'info',
timestamp: '2025-11-28 17:48:27.450'
}
{
message: 'Nov 28, 2025 5:48:27 PM org.apache.aries.spifly.BaseActivator log\n' +
'INFO: Registered provider ch.qos.logback.classic.spi.LogbackServiceProvider of service org.slf4j.spi.SLF4JServiceProvider in bundle ch.qos.logback.classic\n',
level: 'info',
timestamp: '2025-11-28 17:48:27.735'
}
{
message: 'WARNING: A terminally deprecated method in sun.misc.Unsafe has been called\n' +
'WARNING: sun.misc.Unsafe::objectFieldOffset has been called by lombok.permit.Permit\n' +
'WARNING: Please consider reporting this to the maintainers of class lombok.permit.Permit\n' +
'WARNING: sun.misc.Unsafe::objectFieldOffset will be removed in a future release\n',
level: 'info',
timestamp: '2025-11-28 17:48:28.319'
}
{
message: 'WARNING: A terminally deprecated method in sun.misc.Unsafe has been called\n' +
'WARNING: sun.misc.Unsafe::staticFieldBase has been called by com.google.inject.internal.aop.HiddenClassDefiner (file:/Users/apoorvgupta/Library/Application Support/Code/User/globalStorage/redhat.java/1.50.0/config_mac/org.eclipse.osgi/69/0/.cp/jars/guice-5.1.0-classes.jar)\n' +
'WARNING: Please consider reporting this to the maintainers of class com.google.inject.internal.aop.HiddenClassDefiner\n' +
'WARNING: sun.misc.Unsafe::staticFieldBase will be removed in a future release\n',
level: 'info',
timestamp: '2025-11-28 17:48:28.554'
}
{
message: 'Nov 28, 2025 5:48:29 PM com.microsoft.java.debug.plugin.internal.JavaDebuggerServerPlugin start\n' +
'INFO: Starting com.microsoft.java.debug.plugin\n',
level: 'info',
timestamp: '2025-11-28 17:48:29.539'
}
{
message: 'Nov 28, 2025 5:48:46 PM com.microsoft.java.debug.core.UsageDataSession recordInfo\n' +
'INFO: launch debug info\n',
level: 'info',
timestamp: '2025-11-28 17:48:46.326'
}
{
message: 'Nov 28, 2025 5:48:51 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:48:51.548'
}
{
message: 'Nov 28, 2025 5:53:46 PM com.microsoft.java.debug.core.UsageDataSession submitUsageData\n' +
'INFO: session usage data summary\n',
level: 'info',
timestamp: '2025-11-28 17:53:46.401'
}
{
message: 'Nov 28, 2025 5:53:53 PM com.microsoft.java.debug.core.UsageDataSession recordInfo\n' +
'INFO: launch debug info\n',
level: 'info',
timestamp: '2025-11-28 17:53:53.266'
}
{
message: 'Nov 28, 2025 5:53:53 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:53:53.538'
}
{
message: 'Nov 28, 2025 5:55:37 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:55:37.868'
}
{
message: 'Nov 28, 2025 5:55:39 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:55:39.318'
}
{
message: 'Nov 28, 2025 5:55:41 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:55:41.167'
}
{
message: 'Nov 28, 2025 5:56:03 PM com.microsoft.java.debug.core.UsageDataSession submitUsageData\n' +
'INFO: session usage data summary\n',
level: 'info',
timestamp: '2025-11-28 17:56:03.623'
}
{
message: 'Nov 28, 2025 5:56:03 PM com.microsoft.java.debug.core.UsageDataSession recordInfo\n' +
'INFO: launch debug info\n',
level: 'info',
timestamp: '2025-11-28 17:56:03.947'
}
{
message: 'Nov 28, 2025 5:56:04 PM com.microsoft.java.debug.core.UsageDataSession recordResponse\n' +
'WARNING: abnormal response\n',
level: 'info',
timestamp: '2025-11-28 17:56:04.218'
}

[github-actions]

Hi Apoorv Gupta (@apoorv-gupta), I'm an AI Support assistant here to help with your issue. While the team reviews your request, I wanted to provide some possible tips and documentation that might help you in the meantime.

Suggestions

• Toggle the “Enable Logical Structure” button (the {} icon) in the VARIABLES pane to switch between raw field view and logical view for Map instances.
• Ensure you’re running the latest Java Debug extension (microsoft.java-debug) and restart VS Code.
• If the problem persists, please open a new issue in the Java Debugger repo with a minimal reproducible example:
  • https://github.com/microsoft/vscode-java-debug/issues

The team will respond to your issue shortly. I hope these suggestions are helpful in the meantime. If this comment helped you, please give it a 👍. If the suggestion was not helpful or incorrect, please give it a 👎. Your feedback helps us improve!

[apoorv-gupta]

I have checked “Enable Logical Structure” in the user preferences. I have also tried unchecking and re-checking it and restarting VSCode

[apoorv-gupta]

Jinbo Wang (@testforstephen)

I accidentally clicked "resolve" while adding a comment. Could you please reopen this issue? It's about unexpandable HashMap$Node in the debugger (repro attached). Thanks!

[apoorv-gupta]

ok I have the permission to reopen the issue now