diff --git a/org.eclipse.jdt.ls.core/META-INF/MANIFEST.MF b/org.eclipse.jdt.ls.core/META-INF/MANIFEST.MF
index 80f81aad40..91f5fa4369 100644
--- a/org.eclipse.jdt.ls.core/META-INF/MANIFEST.MF
+++ b/org.eclipse.jdt.ls.core/META-INF/MANIFEST.MF
@@ -37,7 +37,6 @@ Export-Package: org.eclipse.jdt.ls.core.internal;x-friends:="org.eclipse.jdt.ls.
  org.eclipse.jdt.ls.core.internal.commands;x-friends:="org.eclipse.jdt.ls.tests",
  org.eclipse.jdt.ls.core.internal.contentassist;x-friends:="org.eclipse.jdt.ls.tests",
  org.eclipse.jdt.ls.core.internal.corext.codemanipulation;x-friends:="org.eclipse.jdt.ls.tests",
- org.eclipse.jdt.ls.core.internal.corext.template.java;x-friends:="org.eclipse.jdt.ls.tests",
  org.eclipse.jdt.ls.core.internal.corext.dom;x-internal:=true,
  org.eclipse.jdt.ls.core.internal.corext.refactoring;x-internal:=true,
  org.eclipse.jdt.ls.core.internal.corext.refactoring.changes;x-internal:=true,
@@ -46,6 +45,7 @@ Export-Package: org.eclipse.jdt.ls.core.internal;x-friends:="org.eclipse.jdt.ls.
  org.eclipse.jdt.ls.core.internal.corext.refactoring.reorg;x-internal:=true,
  org.eclipse.jdt.ls.core.internal.corext.refactoring.tagging;x-internal:=true,
  org.eclipse.jdt.ls.core.internal.corext.refactoring.util;x-internal:=true,
+ org.eclipse.jdt.ls.core.internal.corext.template.java;x-friends:="org.eclipse.jdt.ls.tests",
  org.eclipse.jdt.ls.core.internal.corext.util;x-internal:=true,
  org.eclipse.jdt.ls.core.internal.corrections;x-internal:=true,
  org.eclipse.jdt.ls.core.internal.corrections.proposals;x-internal:=true,
@@ -56,9 +56,10 @@ Export-Package: org.eclipse.jdt.ls.core.internal;x-friends:="org.eclipse.jdt.ls.
  org.eclipse.jdt.ls.core.internal.lsp;x-friends:="org.eclipse.jdt.ls.tests",
  org.eclipse.jdt.ls.core.internal.managers;x-friends:="org.eclipse.jdt.ls.tests,org.eclipse.jdt.ls.tests.syntaxserver",
  org.eclipse.jdt.ls.core.internal.preferences;x-friends:="org.eclipse.jdt.ls.tests,org.eclipse.jdt.ls.tests.syntaxserver",
+ org.eclipse.jdt.ls.core.internal.semantictokens;x-friends:="org.eclipse.jdt.ls.tests",
  org.eclipse.jdt.ls.core.internal.syntaxserver;x-friends:="org.eclipse.jdt.ls.tests.syntaxserver",
  org.eclipse.jdt.ls.core.internal.text.correction;x-friends:="org.eclipse.jdt.ls.tests",
- org.eclipse.jdt.ls.core.internal.semantictokens;x-friends:="org.eclipse.jdt.ls.tests"
+ org.eclipse.jdt.ls.internal.gradle.checksums;x-friends:="org.eclipse.jdt.ls.tests"
 Bundle-ClassPath: lib/jsoup-1.9.2.jar,
  lib/remark-1.2.0.jar,
  .
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/ExceptionFactory.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/ExceptionFactory.java
new file mode 100644
index 0000000000..ee01ae8a66
--- /dev/null
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/ExceptionFactory.java
@@ -0,0 +1,36 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.core.internal;
+
+import org.eclipse.core.runtime.CoreException;
+
+/**
+ *
+ * @author snjeza
+ *
+ */
+public class ExceptionFactory {
+
+	private ExceptionFactory() {
+	}
+
+	public static CoreException newException(String message) {
+		return new CoreException(StatusFactory.newErrorStatus(message));
+	}
+
+	public static CoreException newException(Throwable e) {
+		return new CoreException(StatusFactory.newErrorStatus(e.getMessage(), e));
+	}
+
+}
+
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/JobHelpers.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/JobHelpers.java
index ca0e83e7bb..f5a79e1bce 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/JobHelpers.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/JobHelpers.java
@@ -210,6 +210,10 @@ public static void waitForJobs(String jobFamily, IProgressMonitor monitor) {
 		}
 	}
 
+	public static void waitForLoadingGradleVersionJob() {
+		waitForJobs(LoadingGradleVersionJobMatcher.INSTANCE, MAX_TIME_MILLIS);
+	}
+
 	interface IJobMatcher {
 
 		boolean matches(Job job);
@@ -239,6 +243,17 @@ public boolean matches(Job job) {
 
 	}
 
+	static class LoadingGradleVersionJobMatcher implements IJobMatcher {
+
+		public static final IJobMatcher INSTANCE = new LoadingGradleVersionJobMatcher();
+
+		@Override
+		public boolean matches(Job job) {
+			return job.getClass().getName().matches("org.eclipse.buildship.core.internal.util.gradle.PublishedGradleVersionsWrapper.LoadVersionsJob");
+		}
+
+	}
+
 	static class DownloadSourcesJobMatcher implements IJobMatcher {
 
 		public static final IJobMatcher INSTANCE = new DownloadSourcesJobMatcher();
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleBuildSupport.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleBuildSupport.java
index d77fab2642..c4d15b1341 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleBuildSupport.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleBuildSupport.java
@@ -14,6 +14,7 @@
 
 import java.io.File;
 import java.nio.file.Paths;
+import java.util.Optional;
 
 import org.eclipse.buildship.core.BuildConfiguration;
 import org.eclipse.buildship.core.GradleBuild;
@@ -56,10 +57,17 @@ public void update(IProject project, boolean force, IProgressMonitor monitor) th
 			return;
 		}
 		JavaLanguageServerPlugin.logInfo("Starting Gradle update for " + project.getName());
-		String projectPath = project.getLocation().toFile().getAbsolutePath();
-		BuildConfiguration buildConfiguration = GradleProjectImporter.getBuildConfiguration(Paths.get(projectPath));
-		GradleBuild build = GradleCore.getWorkspace().createBuild(buildConfiguration);
-		build.synchronize(monitor);
+		if (force) {
+			String projectPath = project.getLocation().toFile().getAbsolutePath();
+			BuildConfiguration buildConfiguration = GradleProjectImporter.getBuildConfiguration(Paths.get(projectPath));
+			GradleBuild build = GradleCore.getWorkspace().createBuild(buildConfiguration);
+			build.synchronize(monitor);
+		} else {
+			Optional<GradleBuild> build = GradleCore.getWorkspace().getBuild(project);
+			if (build.isPresent()) {
+				build.get().synchronize(monitor);
+			}
+		}
 	}
 
 	@Override
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleProjectImporter.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleProjectImporter.java
index 73885f41d8..2909c4bf1a 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleProjectImporter.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/GradleProjectImporter.java
@@ -12,6 +12,8 @@
  *******************************************************************************/
 package org.eclipse.jdt.ls.core.internal.managers;
 
+import static java.util.Arrays.asList;
+
 import java.io.File;
 import java.io.FilenameFilter;
 import java.nio.file.Files;
@@ -42,6 +44,11 @@
 import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
 import org.eclipse.jdt.ls.core.internal.ProjectUtils;
 import org.eclipse.jdt.ls.core.internal.preferences.PreferenceManager;
+import org.eclipse.jdt.ls.internal.gradle.checksums.ValidationResult;
+import org.eclipse.jdt.ls.internal.gradle.checksums.WrapperValidator;
+import org.eclipse.lsp4j.ExecuteCommandParams;
+import org.eclipse.lsp4j.MessageParams;
+import org.eclipse.lsp4j.MessageType;
 
 /**
  * @author Fred Bricon
@@ -59,6 +66,17 @@ public class GradleProjectImporter extends AbstractProjectImporter {
 
 	public static final String IMPORTING_GRADLE_PROJECTS = "Importing Gradle project(s)";
 
+	//@formatter:off
+	public static final String GRADLE_WRAPPER_CHEKSUM_WARNING_TEMPLATE =
+			"Security Warning! The gradle wrapper '@wrapper@' could be malicious. "
+			+ "If you trust it, please add \n"
+			+ "`{\"sha256\": \"@checksum@\","
+			+ "\n\"allowed\": true}`"
+			+ "\n to the `java.import.gradle.wrapper.checksums` preference."
+			+ ""
+			.replaceAll("\n", System.lineSeparator());
+	//@formatter:on
+
 	private Collection<Path> directories;
 
 	/* (non-Javadoc)
@@ -107,13 +125,39 @@ private void importDir(Path rootFolder, IProgressMonitor monitor) {
 	}
 
 	public static GradleDistribution getGradleDistribution(Path rootFolder) {
-		if (JavaLanguageServerPlugin.getPreferencesManager() != null && JavaLanguageServerPlugin.getPreferencesManager().getPreferences().isGradleWrapperEnabled() && Files.exists(rootFolder.resolve("gradlew"))) {
-			return GradleDistribution.fromBuild();
+		PreferenceManager preferencesManager = JavaLanguageServerPlugin.getPreferencesManager();
+		if (preferencesManager != null && preferencesManager.getPreferences().isGradleWrapperEnabled() && Files.exists(rootFolder.resolve("gradlew"))) {
+			WrapperValidator validator = new WrapperValidator();
+			try {
+				ValidationResult result = validator.checkWrapper(rootFolder.toFile().getAbsolutePath());
+				if (result.isValid()) {
+					WrapperGradleDistribution gradleDistribution = GradleDistribution.fromBuild();
+					return gradleDistribution;
+				} else {
+					if (!WrapperValidator.contains(result.getChecksum())) {
+						ProjectsManager pm = JavaLanguageServerPlugin.getProjectsManager();
+						if (pm != null && pm.getConnection() != null) {
+							if (preferencesManager.getClientPreferences().isGradleChecksumWrapperPromptSupport()) {
+								String id = "gradle/checksum/prompt";
+								ExecuteCommandParams params = new ExecuteCommandParams(id, asList(result.getWrapperJar(), result.getChecksum()));
+								pm.getConnection().sendNotification(params);
+							} else {
+								//@formatter:off
+								String message = GRADLE_WRAPPER_CHEKSUM_WARNING_TEMPLATE.replaceAll("@wrapper@", result.getWrapperJar()).replaceAll("@checksum@", result.getChecksum());
+								//@formatter:on
+								pm.getConnection().showMessage(new MessageParams(MessageType.Error, message));
+							}
+						}
+					}
+				}
+			} catch (CoreException e) {
+				JavaLanguageServerPlugin.logException(e.getMessage(), e);
+			}
 		}
-		if (JavaLanguageServerPlugin.getPreferencesManager() != null && JavaLanguageServerPlugin.getPreferencesManager().getPreferences().getGradleVersion() != null) {
+		if (preferencesManager != null && preferencesManager.getPreferences().getGradleVersion() != null) {
 			List<GradleVersion> versions = CorePlugin.publishedGradleVersions().getVersions();
 			GradleVersion gradleVersion = null;
-			String versionString = JavaLanguageServerPlugin.getPreferencesManager().getPreferences().getGradleVersion();
+			String versionString = preferencesManager.getPreferences().getGradleVersion();
 			GradleVersion requiredVersion = GradleVersion.version(versionString);
 			for (GradleVersion version : versions) {
 				if (version.compareTo(requiredVersion) == 0) {
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/ProjectsManager.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/ProjectsManager.java
index 6540bf983f..b0cdc97266 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/ProjectsManager.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/managers/ProjectsManager.java
@@ -372,6 +372,10 @@ public void setConnection(JavaLanguageClient client) {
 		this.client = client;
 	}
 
+	public JavaLanguageClient getConnection() {
+		return this.client;
+	}
+
 	private String getWorkspaceInfo() {
 		StringBuilder b = new StringBuilder();
 		b.append("Projects:\n");
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/ClientPreferences.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/ClientPreferences.java
index fcbd019aef..4d1e2a1a23 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/ClientPreferences.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/ClientPreferences.java
@@ -221,6 +221,14 @@ public boolean isClientDocumentSymbolProviderRegistered() {
 		return Boolean.parseBoolean(extendedClientCapabilities.getOrDefault("clientDocumentSymbolProvider", "false").toString());
 	}
 
+	public boolean isActionableNotificationSupported() {
+		return Boolean.parseBoolean(extendedClientCapabilities.getOrDefault("actionableNotificationSupported", "false").toString());
+	}
+
+	public boolean isGradleChecksumWrapperPromptSupport() {
+		return Boolean.parseBoolean(extendedClientCapabilities.getOrDefault("gradleChecksumWrapperPromptSupport", "false").toString());
+	}
+
 	public boolean isSupportsCompletionDocumentationMarkdown() {
 		//@formatter:off
 		return v3supported && capabilities.getTextDocument().getCompletion() != null
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/Preferences.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/Preferences.java
index e5b0fb4522..0b437f2422 100644
--- a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/Preferences.java
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/preferences/Preferences.java
@@ -31,6 +31,7 @@
 import java.util.UUID;
 
 import org.eclipse.core.internal.resources.PreferenceInitializer;
+import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.preferences.DefaultScope;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
@@ -39,9 +40,12 @@
 import org.eclipse.jdt.internal.core.manipulation.MembersOrderPreferenceCacheCommon;
 import org.eclipse.jdt.ls.core.internal.IConstants;
 import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
+import org.eclipse.jdt.ls.core.internal.ProjectUtils;
 import org.eclipse.jdt.ls.core.internal.ResourceUtils;
 import org.eclipse.jdt.ls.core.internal.RuntimeEnvironment;
 import org.eclipse.jdt.ls.core.internal.contentassist.TypeFilter;
+import org.eclipse.jdt.ls.core.internal.managers.ProjectsManager;
+import org.eclipse.jdt.ls.internal.gradle.checksums.WrapperValidator;
 import org.eclipse.lsp4j.MessageType;
 
 /**
@@ -60,7 +64,7 @@ public class Preferences {
 	 * Specifies Java Execution Environments.
 	 */
 	public static final String JAVA_CONFIGURATION_RUNTIMES = "java.configuration.runtimes";
-	public static final Set<String> JAVA_CONFIGURATION_RUNTIMES_DEFAULT;
+	public static final List<String> JAVA_CONFIGURATION_RUNTIMES_DEFAULT;
 	/**
 	 * Specifies the file path to the formatter xml url.
 	 */
@@ -209,6 +213,15 @@ public class Preferences {
 	 */
 	public static final String SELECTIONRANGE_ENABLED_KEY = "java.selectionRange.enabled";
 
+	/**
+	 * A named preference that holds the allowed gradle wrapper sha256 checksums.
+	 * <p>
+	 * Value is of type <code>String</code>: list of checksums.
+	 * </p>
+	 */
+	public static final String JAVA_GRADLE_WRAPPER_SHA256_KEY = "java.imports.gradle.wrapper.checksums";
+	public static final List<String> JAVA_GRADLE_WRAPPER_SHA256_DEFAULT;
+
 	/**
 	 * A named preference that holds the favorite static members.
 	 * <p>
@@ -412,6 +425,8 @@ public class Preferences {
 	private String mavenUserSettings;
 
 	private List<String> javaCompletionFavoriteMembers;
+	private List<String> sha256Allowed;
+	private List<String> sha256Disallowed;
 
 	private List<String> javaImportExclusions = new LinkedList<>();
 	private ReferencedLibraries referencedLibraries;
@@ -430,7 +445,8 @@ public class Preferences {
 
 	static {
 		JAVA_IMPORT_EXCLUSIONS_DEFAULT = new LinkedList<>();
-		JAVA_CONFIGURATION_RUNTIMES_DEFAULT = new HashSet<>();
+		JAVA_CONFIGURATION_RUNTIMES_DEFAULT = new ArrayList<>();
+		JAVA_GRADLE_WRAPPER_SHA256_DEFAULT = new ArrayList<>();
 		JAVA_IMPORT_EXCLUSIONS_DEFAULT.add("**/node_modules/**");
 		JAVA_IMPORT_EXCLUSIONS_DEFAULT.add("**/.metadata/**");
 		JAVA_IMPORT_EXCLUSIONS_DEFAULT.add("**/archetype-resources/**");
@@ -731,6 +747,43 @@ public static Preferences createFrom(Map<String, Object> configuration) {
 		List<String> javaCompletionFavoriteMembers = getList(configuration, JAVA_COMPLETION_FAVORITE_MEMBERS_KEY, JAVA_COMPLETION_FAVORITE_MEMBERS_DEFAULT);
 		prefs.setJavaCompletionFavoriteMembers(javaCompletionFavoriteMembers);
 
+		List<?> gradleWrapperList = getList(configuration, JAVA_GRADLE_WRAPPER_SHA256_KEY, JAVA_GRADLE_WRAPPER_SHA256_DEFAULT);
+		List<String> sha256Allowed = new ArrayList<>();
+		List<String> sha256Disallowed = new ArrayList<>();
+		for (Object object : gradleWrapperList) {
+			if (object instanceof Map) {
+				Map<?, ?> map = (Map<?, ?>) object;
+				final ChecksumWrapper sha256 = prefs.new ChecksumWrapper();
+				sha256.allowed = true;
+				map.forEach((k, v) -> {
+					if (k instanceof String) {
+						switch ((String) k) {
+							case "sha256":
+								if (v instanceof String) {
+									sha256.checksum = (String) v;
+								}
+								break;
+							case "allowed":
+								if (v instanceof Boolean) {
+									sha256.allowed = (Boolean) v;
+								}
+								break;
+							default:
+								break;
+						}
+					}
+				});
+				if (sha256.checksum != null) {
+					if (sha256.allowed) {
+						sha256Allowed.add(sha256.checksum);
+					} else {
+						sha256Disallowed.add(sha256.checksum);
+					}
+				}
+			}
+		}
+		prefs.putSha256(sha256Allowed, sha256Disallowed);
+
 		String mavenUserSettings = getString(configuration, MAVEN_USER_SETTINGS_KEY, null);
 		prefs.setMavenUserSettings(mavenUserSettings);
 
@@ -771,7 +824,7 @@ public static Preferences createFrom(Map<String, Object> configuration) {
 		int staticOnDemandThreshold = getInt(configuration, IMPORTS_STATIC_ONDEMANDTHRESHOLD, IMPORTS_STATIC_ONDEMANDTHRESHOLD_DEFAULT);
 		prefs.setStaticImportOnDemandThreshold(staticOnDemandThreshold);
 
-		List<?> runtimeList = getList(configuration, JAVA_CONFIGURATION_RUNTIMES, JAVA_IMPORT_ORDER_DEFAULT);
+		List<?> runtimeList = getList(configuration, JAVA_CONFIGURATION_RUNTIMES, JAVA_CONFIGURATION_RUNTIMES_DEFAULT);
 		Set<RuntimeEnvironment> runtimes = new HashSet<>();
 		boolean[] hasDefault = { false };
 		for (Object object : runtimeList) {
@@ -888,6 +941,24 @@ public Preferences setJavaCompletionFavoriteMembers(List<String> javaCompletionF
 		return this;
 	}
 
+	public Preferences putSha256(List<String> sha256Allowed, List<String> sha256Disallowed) {
+		List<String> oldAllowed = this.sha256Allowed;
+		List<String> oldDisallowed = this.sha256Disallowed;
+		WrapperValidator.clear();
+		this.sha256Allowed = sha256Allowed;
+		if (sha256Disallowed != null) {
+			WrapperValidator.disallow(sha256Disallowed);
+		}
+		this.sha256Disallowed = sha256Disallowed;
+		ProjectsManager projectsManager = JavaLanguageServerPlugin.getProjectsManager();
+		if (projectsManager != null && (!Objects.equals(oldAllowed, this.sha256Allowed) || !Objects.equals(oldDisallowed, this.sha256Disallowed))) {
+			for (IProject project : ProjectUtils.getGradleProjects()) {
+				projectsManager.updateProject(project, true);
+			}
+		}
+		return this;
+	}
+
 	private Preferences setMembersSortOrder(String sortOrder) {
 		if (sortOrder != null) {
 			IEclipsePreferences fPreferenceStore = InstanceScope.INSTANCE.getNode(IConstants.PLUGIN_ID);
@@ -1092,6 +1163,10 @@ public String[] getJavaCompletionFavoriteMembers() {
 		return javaCompletionFavoriteMembers.toArray(new String[0]);
 	}
 
+	public List<String> getSha256Allowed() {
+		return sha256Allowed;
+	}
+
 	public String getJavaHome() {
 		return javaHome;
 	}
@@ -1367,4 +1442,9 @@ public Preferences setStaticImportOnDemandThreshold(int staticImportOnDemandThre
 		defEclipsePrefs.put(CodeStyleConfiguration.ORGIMPORTS_STATIC_ONDEMANDTHRESHOLD, String.valueOf(this.staticImportOnDemandThreshold));
 		return this;
 	}
+
+	class ChecksumWrapper {
+		private String checksum;
+		private boolean allowed;
+	}
 }
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/DownloadChecksumJob.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/DownloadChecksumJob.java
new file mode 100644
index 0000000000..b0ad3022bb
--- /dev/null
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/DownloadChecksumJob.java
@@ -0,0 +1,116 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.internal.gradle.checksums;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.SubMonitor;
+import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
+
+import com.google.common.base.Charsets;
+import com.google.common.io.CharStreams;
+
+/**
+ *
+ * @author snjeza
+ *
+ */
+public class DownloadChecksumJob extends Job {
+
+	public static final String WRAPPER_VALIDATOR_JOBS = "WrapperValidatorJobs";
+
+	private final BlockingQueue<String> queue = new LinkedBlockingQueue<>();
+
+	public DownloadChecksumJob() {
+		super("Download Gradle Wrapper checksums");
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.core.runtime.jobs.Job#run(org.eclipse.core.runtime.IProgressMonitor)
+	 */
+	@Override
+	protected IStatus run(IProgressMonitor monitor) {
+		int totalWork = 2 * queue.size();
+		SubMonitor subMonitor = SubMonitor.convert(monitor, totalWork);
+		while (!queue.isEmpty() && !monitor.isCanceled()) {
+			String urlStr = queue.poll();
+			URL url;
+			try {
+				url = new URL(urlStr);
+			} catch (MalformedURLException e1) {
+				JavaLanguageServerPlugin.logInfo("Invalid wrapper URL " + urlStr);
+				continue;
+			}
+			subMonitor.setTaskName(url.toString());
+			final HttpURLConnection connection;
+			try {
+				connection = (HttpURLConnection) url.openConnection();
+				connection.setConnectTimeout(30000);
+				connection.setReadTimeout(30000);
+			} catch (IOException e) {
+				JavaLanguageServerPlugin.logException(e.getMessage(), e);
+				continue;
+			}
+			try (AutoCloseable closer = (() -> connection.disconnect()); InputStreamReader reader = new InputStreamReader(connection.getInputStream(), Charsets.UTF_8);) {
+				String sha256 = CharStreams.toString(reader);
+				File sha256File = new File(WrapperValidator.getSha256CacheFile(), WrapperValidator.getFileName(urlStr));
+				write(sha256File, sha256);
+				WrapperValidator.allow(sha256);
+				subMonitor.worked(2);
+			} catch (Exception e) {
+				JavaLanguageServerPlugin.logException("Cannot download Gradle sha256 checksum: " + url.toString(), e);
+				continue;
+			}
+		}
+		subMonitor.done();
+		return Status.OK_STATUS;
+	}
+
+	public void add(String urlStr) {
+		queue.add(urlStr);
+	}
+
+	private void write(File sha256File, String sha256) {
+		try {
+			Files.write(Paths.get(sha256File.getAbsolutePath()), sha256.getBytes());
+		} catch (IOException e) {
+			JavaLanguageServerPlugin.logException(e);
+		}
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.core.runtime.jobs.Job#belongsTo(java.lang.Object)
+	 */
+	@Override
+	public boolean belongsTo(Object family) {
+		return WRAPPER_VALIDATOR_JOBS.equals(family);
+	}
+
+	public boolean isEmpty() {
+		return queue.isEmpty();
+	}
+}
+
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/HashProvider.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/HashProvider.java
new file mode 100644
index 0000000000..000821c122
--- /dev/null
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/HashProvider.java
@@ -0,0 +1,64 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.internal.gradle.checksums;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.security.DigestInputStream;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
+
+/**
+ *
+ * @author snjeza
+ *
+ */
+public class HashProvider {
+	public static final String SHA256 = "SHA-256";
+
+	private String alghorithm;
+
+	public HashProvider() {
+		this(SHA256);
+	}
+
+	public HashProvider(String alghorithm) {
+		this.alghorithm = alghorithm;
+	}
+
+	public String getChecksum(File file) throws IOException {
+		MessageDigest messageDigest;
+		try {
+			messageDigest = MessageDigest.getInstance(alghorithm);
+		} catch (NoSuchAlgorithmException e) {
+			JavaLanguageServerPlugin.logException(e.getMessage(), e);
+			return null;
+		}
+		try (DigestInputStream dis = new DigestInputStream(new FileInputStream(file), messageDigest)) {
+			byte[] bytes = new byte[32768];
+			while (dis.read(bytes) != -1) {
+				;
+			}
+			messageDigest = dis.getMessageDigest();
+		}
+		StringBuilder result = new StringBuilder();
+		for (byte b : messageDigest.digest()) {
+			result.append(String.format("%02x", b));
+		}
+		return result.toString();
+	}
+}
+
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/ValidationResult.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/ValidationResult.java
new file mode 100644
index 0000000000..44dc2497b4
--- /dev/null
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/ValidationResult.java
@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.internal.gradle.checksums;
+
+/**
+ *
+ * @author snjeza
+ *
+ */
+public class ValidationResult {
+
+	private String checksum;
+	private String wrapperJar;
+	private boolean valid;
+
+	public ValidationResult(String wrapperJar, String checksum, boolean valid) {
+		this.wrapperJar = wrapperJar;
+		this.checksum = checksum;
+		this.valid = valid;
+	}
+
+	public String getChecksum() {
+		return checksum;
+	}
+
+	public boolean isValid() {
+		return valid;
+	}
+
+	public String getWrapperJar() {
+		return wrapperJar;
+	}
+
+}
+
diff --git a/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/WrapperValidator.java b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/WrapperValidator.java
new file mode 100644
index 0000000000..d6e38559c3
--- /dev/null
+++ b/org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/internal/gradle/checksums/WrapperValidator.java
@@ -0,0 +1,230 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.internal.gradle.checksums;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.NullProgressMonitor;
+import org.eclipse.core.runtime.OperationCanceledException;
+import org.eclipse.jdt.ls.core.internal.ExceptionFactory;
+import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
+import org.eclipse.jdt.ls.core.internal.JobHelpers;
+import org.eclipse.jdt.ls.core.internal.preferences.PreferenceManager;
+
+import com.google.common.base.Charsets;
+import com.google.common.base.Function;
+import com.google.common.base.Predicate;
+import com.google.common.collect.FluentIterable;
+import com.google.common.collect.ImmutableList;
+import com.google.common.io.CharStreams;
+import com.google.common.io.Closeables;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.reflect.TypeToken;
+
+/**
+ *
+ * @author snjeza
+ *
+ */
+public class WrapperValidator {
+
+	private static final int QUEUE_LENGTH = 20;
+	private static final String WRAPPER_CHECKSUM_URL = "wrapperChecksumUrl";
+	private static final String GRADLE_WRAPPER_JAR = "gradle/wrapper/gradle-wrapper.jar";
+
+	private static Set<String> allowed = new HashSet<>();
+	private static Set<String> disallowed = new HashSet<>();
+	private static AtomicBoolean downloaded = new AtomicBoolean(false);
+	private HashProvider hashProvider;
+	private int queueLength;
+
+	public WrapperValidator(int queueLength) {
+		this.hashProvider = new HashProvider();
+		queueLength = queueLength;
+	}
+
+	public WrapperValidator() {
+		this(QUEUE_LENGTH);
+	}
+
+	public ValidationResult checkWrapper(String baseDir) throws CoreException {
+		Path wrapperJar = Paths.get(baseDir, GRADLE_WRAPPER_JAR);
+		if (!wrapperJar.toFile().exists()) {
+			throw ExceptionFactory.newException(wrapperJar.toString() + " doesn't exist.");
+		}
+		if (!downloaded.get() || allowed.isEmpty()) {
+			PreferenceManager preferenceManager = JavaLanguageServerPlugin.getPreferencesManager();
+			if (preferenceManager != null && preferenceManager.getPreferences().getSha256Allowed() != null) {
+				allow(preferenceManager.getPreferences().getSha256Allowed());
+			}
+			File versionFile = getVersionCacheFile();
+			if (!versionFile.exists()) {
+				JobHelpers.waitForLoadingGradleVersionJob();
+			}
+			if (versionFile.exists()) {
+				InputStreamReader reader = null;
+				try {
+					reader = new InputStreamReader(new FileInputStream(versionFile), Charsets.UTF_8);
+					String json = CharStreams.toString(reader);
+					Gson gson = new GsonBuilder().create();
+					TypeToken<List<Map<String, String>>> typeToken = new TypeToken<List<Map<String, String>>>() {
+					};
+					List<Map<String, String>> versions = gson.fromJson(json, typeToken.getType());
+					//@formatter:off
+					ImmutableList<String> wrapperChecksumUrls = FluentIterable
+						.from(versions)
+						.filter(new Predicate<Map<String, String>>() {
+							@Override
+							public boolean apply(Map<String, String> input) {
+								return input.get(WRAPPER_CHECKSUM_URL) != null;
+							}
+						})
+						.transform(new Function<Map<String, String>, String>() {
+							@Override
+							public String apply(Map<String, String> input) {
+								return input.get(WRAPPER_CHECKSUM_URL);
+							}
+						})
+					.toList();
+					// @formatter:on
+					DownloadChecksumJob downloadJob = new DownloadChecksumJob();
+					int count = 0;
+					File cacheDir = getSha256CacheFile();
+					for (String wrapperChecksumUrl : wrapperChecksumUrls) {
+						try {
+							String fileName = getFileName(wrapperChecksumUrl);
+							if (fileName == null) {
+								continue;
+							}
+							File sha256File = new File(cacheDir, fileName);
+							if (!sha256File.exists() || sha256File.lastModified() < versionFile.lastModified()) {
+								count++;
+								if (count > queueLength) {
+									downloadJob.schedule();
+									downloadJob = new DownloadChecksumJob();
+									count = 0;
+								}
+								downloadJob.add(wrapperChecksumUrl);
+							} else {
+								String sha256 = read(sha256File);
+								allowed.add(sha256);
+							}
+						} catch (Exception e) {
+							JavaLanguageServerPlugin.logException(e.getMessage(), e);
+						}
+					}
+					if (!downloadJob.isEmpty()) {
+						downloadJob.schedule();
+					}
+					JobHelpers.waitForJobs(DownloadChecksumJob.WRAPPER_VALIDATOR_JOBS, new NullProgressMonitor());
+					downloaded.set(true);
+				} catch (IOException | OperationCanceledException e) {
+					throw ExceptionFactory.newException(e);
+				} finally {
+					try {
+						Closeables.close(reader, false);
+					} catch (IOException e) {
+						// ignore
+					}
+				}
+			}
+		}
+		try {
+			String sha256 = hashProvider.getChecksum(wrapperJar.toFile());
+			return new ValidationResult(wrapperJar.toString(), sha256, allowed.contains(sha256));
+		} catch (IOException e) {
+			throw ExceptionFactory.newException(e);
+		}
+	}
+
+	public static String getFileName(String url) {
+		int index = url.lastIndexOf("/");
+		if (index < 0 || url.length() < index + 1) {
+			JavaLanguageServerPlugin.logInfo("Invalid wrapper URL " + url);
+			return null;
+		}
+		return url.substring(index + 1);
+	}
+
+	private static String read(File file) {
+		Optional<String> firstLine;
+		try {
+			firstLine = Files.lines(Paths.get(file.getAbsolutePath()), StandardCharsets.UTF_8).findFirst();
+		} catch (IOException e) {
+			JavaLanguageServerPlugin.logException(e);
+			return null;
+		}
+		if (firstLine.isPresent()) {
+			return firstLine.get();
+		}
+		return null;
+	}
+
+	private static File getVersionCacheFile() {
+		return new File(System.getProperty("user.home"), ".tooling/gradle/versions.json");
+	}
+
+	public static File getSha256CacheFile() {
+		String checksumCache = System.getProperty("gradle.checksum.cacheDir");
+		File file;
+		if (checksumCache == null || checksumCache.isEmpty()) {
+			file = new File(System.getProperty("user.home"), ".tooling/gradle/checksums");
+		} else {
+			file = new File(checksumCache);
+		}
+		file.mkdirs();
+		return file;
+	}
+
+	public static void clear() {
+		allowed.clear();
+		disallowed.clear();
+	}
+
+	public static void allow(Collection<String> c) {
+		allowed.addAll(c);
+	}
+
+	public static void allow(String checksum) {
+		allowed.add(checksum);
+	}
+
+	public static void disallow(Collection<String> c) {
+		disallowed.addAll(c);
+	}
+
+	public static boolean contains(String checksum) {
+		return disallowed.contains(checksum);
+	}
+
+	public static int size() {
+		return allowed.size() + disallowed.size();
+	}
+
+}
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/build.gradle b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/build.gradle
new file mode 100644
index 0000000000..cc67a20f14
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/build.gradle
@@ -0,0 +1,33 @@
+/*
+ * This build file was auto generated by running the Gradle 'init' task
+ * by 'fbricon' at '24/10/16 11:28' with Gradle 3.0
+ *
+ * This generated file contains a sample Java project to get you started.
+ * For more details take a look at the Java Quickstart chapter in the Gradle
+ * user guide available at https://docs.gradle.org/3.0/userguide/tutorial_java_projects.html
+ */
+
+// Apply the java plugin to add support for Java
+apply plugin: 'java'
+apply plugin: 'eclipse'
+
+sourceCompatibility = 1.8
+
+// In this section you declare where to find the dependencies of your project
+repositories {
+    // Use 'jcenter' for resolving your dependencies.
+    // You can declare any Maven/Ivy/file repository here.
+    jcenter()
+}
+
+// In this section you declare the dependencies for your production and test code
+dependencies {
+    // The production code uses the SLF4J logging API at compile time
+    compile 'org.slf4j:slf4j-api:1.7.21'
+
+    // Declare the dependency for your favourite test framework you want to use in your tests.
+    // TestNG is also supported by the Gradle Test task. Just change the
+    // testCompile dependency to testCompile 'org.testng:testng:6.8.1' and add
+    // 'test.useTestNG()' to your build script.
+    testCompile 'junit:junit:4.12'
+}
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle.properties b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle.properties
new file mode 100644
index 0000000000..792d600548
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle.properties
@@ -0,0 +1 @@
+#
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle/wrapper/gradle-wrapper.jar b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000000..2713e396b3
Binary files /dev/null and b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle/wrapper/gradle-wrapper.properties b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000000..e80808e58f
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Sat May 09 17:34:24 CEST 2020
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.0-bin.zip
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradlew b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradlew
new file mode 100755
index 0000000000..cccdd3d517
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradlew
@@ -0,0 +1,172 @@
+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradlew.bat b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradlew.bat
new file mode 100644
index 0000000000..e95643d6a2
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/gradlew.bat
@@ -0,0 +1,84 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/settings.gradle b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/settings.gradle
new file mode 100644
index 0000000000..9d527fdf87
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/settings.gradle
@@ -0,0 +1,19 @@
+/*
+ * This settings file was auto generated by the Gradle buildInit task
+ * by 'fbricon' at '24/10/16 11:28' with Gradle 3.0
+ *
+ * The settings file is used to specify which projects to include in your build.
+ * In a single project build this file can be empty or even removed.
+ *
+ * Detailed information about configuring a multi-project build in Gradle can be found
+ * in the user guide at https://docs.gradle.org/3.0/userguide/multi_project_builds.html
+ */
+
+/*
+// To declare projects as part of a multi-project build use the 'include' method
+include 'shared'
+include 'api'
+include 'services:webservice'
+*/
+
+rootProject.name = 'gradle-4.0'
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/src/main/java/Library.java b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/src/main/java/Library.java
new file mode 100644
index 0000000000..526aadc25a
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/src/main/java/Library.java
@@ -0,0 +1,11 @@
+/*
+ * This Java source file was auto generated by running 'gradle buildInit --type java-library'
+ * by 'fbricon' at '24/10/16 11:28' with Gradle 3.0
+ *
+ * @author fbricon, @date 24/10/16 11:28
+ */
+public class Library {
+    public boolean someLibraryMethod() {
+        return true;
+    }
+}
diff --git a/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/src/test/java/LibraryTest.java b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/src/test/java/LibraryTest.java
new file mode 100644
index 0000000000..af8df3303c
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/projects/gradle/gradle-4.0/src/test/java/LibraryTest.java
@@ -0,0 +1,15 @@
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+/*
+ * This Java source file was auto generated by running 'gradle init --type java-library'
+ * by 'fbricon' at '24/10/16 11:28' with Gradle 3.0
+ *
+ * @author fbricon, @date 24/10/16 11:28
+ */
+public class LibraryTest {
+    @Test public void testSomeLibraryMethod() {
+        Library classUnderTest = new Library();
+        assertTrue("someLibraryMethod should return 'true'", classUnderTest.someLibraryMethod());
+    }
+}
diff --git a/org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/managers/WrapperValidatorTest.java b/org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/managers/WrapperValidatorTest.java
new file mode 100644
index 0000000000..ea85e40b27
--- /dev/null
+++ b/org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/managers/WrapperValidatorTest.java
@@ -0,0 +1,100 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Red Hat Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.core.internal.managers;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.eclipse.jdt.ls.core.internal.JavaLanguageServerPlugin;
+import org.eclipse.jdt.ls.core.internal.preferences.Preferences;
+import org.eclipse.jdt.ls.internal.gradle.checksums.ValidationResult;
+import org.eclipse.jdt.ls.internal.gradle.checksums.WrapperValidator;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.runners.MockitoJUnitRunner;
+
+/**
+ * @author snjeza
+ *
+ */
+@RunWith(MockitoJUnitRunner.class)
+public class WrapperValidatorTest extends AbstractGradleBasedTest{
+
+	@Before
+	public void setProperty() throws Exception {
+		System.setProperty("gradle.checksum.cacheDir", "target/gradle/checksums");
+		WrapperValidator.clear();
+	}
+
+	@After
+	public void clearProperty() throws IOException {
+		System.clearProperty("gradle.checksum.cacheDir");
+	}
+
+	@Test
+	public void testGradleWrapper() throws Exception {
+		File file = new File(getSourceProjectDirectory(), "gradle/simple-gradle");
+		assertTrue(file.isDirectory());
+		File sha256Directory = WrapperValidator.getSha256CacheFile();
+		assertTrue(sha256Directory.isDirectory());
+		ValidationResult result = new WrapperValidator(100).checkWrapper(file.getAbsolutePath());
+		assertTrue(result.isValid());
+		// test cache
+		assertTrue(sha256Directory.isDirectory());
+		String message = Files.list(Paths.get(sha256Directory.getAbsolutePath())).collect(Collectors.toList()).toString();
+		file = new File(sha256Directory, "gradle-6.3-wrapper.jar.sha256");
+		assertTrue(message, file.isFile());
+		String sha256 = Files.lines(Paths.get(file.getAbsolutePath()), StandardCharsets.UTF_8).findFirst().get();
+		assertEquals("1cef53de8dc192036e7b0cc47584449b0cf570a00d560bfaa6c9eabe06e1fc06", sha256);
+	}
+
+	@Test
+	public void testMissingSha256() throws Exception {
+		Preferences prefs = JavaLanguageServerPlugin.getPreferencesManager().getPreferences();
+		List<String> allowed = prefs.getSha256Allowed();
+		int size = WrapperValidator.size();
+		WrapperValidator wrapperValidator = new WrapperValidator(100);
+		File file = new File(getSourceProjectDirectory(), "gradle/gradle-4.0");
+		List<String> sha256 = new ArrayList<>();
+		try {
+			sha256.add("41c8aa7a337a44af18d8cda0d632ebba469aef34f3041827624ef5c1a4e4419d");
+			prefs.putSha256(null, sha256);
+			assertTrue(file.isDirectory());
+			ValidationResult result = wrapperValidator.checkWrapper(file.getAbsolutePath());
+			assertFalse(result.isValid());
+			size = WrapperValidator.size();
+			assertNotNull(result.getChecksum());
+			prefs.putSha256(sha256, null);
+			result = wrapperValidator.checkWrapper(file.getAbsolutePath());
+			assertTrue(result.isValid());
+		} finally {
+			prefs.putSha256(allowed, null);
+			prefs.putSha256(sha256, null);
+			wrapperValidator.checkWrapper(file.getAbsolutePath());
+			assertEquals(size, WrapperValidator.size());
+		}
+	}
+}