[provide a description of the issue]

Environment

• Operating System: Windows 7
• JDK version: 1.8.0_144
• Visual Studio Code version: 1.18.1
• Java extension version: 0.15.0

After update to 0.15.0, the extension will hang at 100% and crash more than 5 times

Current Result

Crash more than 5 times and shut down the server

Expected Result

Not Crash

Additional Informations

[Warn - 17:28:07] 2017-12-4 17:28:04 Could not load Gradle version information
Cannot download published Gradle versions.
org.gradle.api.UncheckedIOException: Cannot download published Gradle versions.
at com.gradleware.tooling.toolingutils.distribution.PublishedGradleVersions.downloadVersionInformation(PublishedGradleVersions.java:175)
at com.gradleware.tooling.toolingutils.distribution.PublishedGradleVersions.tryToDownloadAndCacheVersions(PublishedGradleVersions.java:159)
at com.gradleware.tooling.toolingutils.distribution.PublishedGradleVersions.create(PublishedGradleVersions.java:119)
at org.eclipse.buildship.core.util.gradle.PublishedGradleVersionsWrapper$LoadVersionsJob.run(PublishedGradleVersionsWrapper.java:66)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1959)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1514)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1026)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:961)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1072)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1385)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1413)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1397)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1546)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
at com.gradleware.tooling.toolingutils.distribution.PublishedGradleVersions.downloadVersionInformation(PublishedGradleVersions.java:172)
... 4 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:397)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:302)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1496)
... 17 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:392)
... 23 more

[Error - 17:28:10] 2017-12-4 17:28:04 An internal error occurred during: "Initialize Workspace".
Could not install Gradle distribution from 'https://services.gradle.org/distributions/gradle-4.3-bin.zip'.
org.gradle.tooling.GradleConnectionException: Could not install Gradle distribution from 'https://services.gradle.org/distributions/gradle-4.3-bin.zip'.
at org.gradle.tooling.internal.consumer.DistributionFactory$ZippedDistribution.getToolingImplementationClasspath(DistributionFactory.java:137)
at org.gradle.tooling.internal.consumer.loader.CachingToolingImplementationLoader.create(CachingToolingImplementationLoader.java:40)
at org.gradle.tooling.internal.consumer.loader.SynchronizedToolingImplementationLoader.create(SynchronizedToolingImplementationLoader.java:43)
at org.gradle.tooling.internal.consumer.connection.LazyConsumerActionExecutor.onStartAction(LazyConsumerActionExecutor.java:101)
at org.gradle.tooling.internal.consumer.connection.LazyConsumerActionExecutor.run(LazyConsumerActionExecutor.java:83)
at org.gradle.tooling.internal.consumer.connection.CancellableConsumerActionExecutor.run(CancellableConsumerActionExecutor.java:45)
at org.gradle.tooling.internal.consumer.connection.ProgressLoggingConsumerActionExecutor.run(ProgressLoggingConsumerActionExecutor.java:58)
at org.gradle.tooling.internal.consumer.connection.RethrowingErrorsConsumerActionExecutor.run(RethrowingErrorsConsumerActionExecutor.java:38)
at org.gradle.tooling.internal.consumer.async.DefaultAsyncConsumerActionExecutor$1$1.run(DefaultAsyncConsumerActionExecutor.java:55)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
at java.lang.Thread.run(Thread.java:748)
at org.gradle.tooling.internal.consumer.BlockingResultHandler.getResult(BlockingResultHandler.java:46)
at org.gradle.tooling.internal.consumer.DefaultModelBuilder.get(DefaultModelBuilder.java:50)
at org.gradle.tooling.internal.consumer.DefaultProjectConnection.getModel(DefaultProjectConnection.java:41)
at org.eclipse.buildship.core.workspace.internal.ConnectionAwareLauncherProxy.newModelBuilder(ConnectionAwareLauncherProxy.java:64)
at org.eclipse.buildship.core.workspace.internal.DefaultModelProvider.fetchModel(DefaultModelProvider.java:68)
at org.eclipse.buildship.core.workspace.internal.DefaultModelProvider.supportsCompositeBuilds(DefaultModelProvider.java:165)
at org.eclipse.buildship.core.workspace.internal.DefaultModelProvider.fetchModels(DefaultModelProvider.java:75)
at org.eclipse.buildship.core.workspace.internal.DefaultModelProvider.fetchEclipseGradleProjects(DefaultModelProvider.java:99)
at org.eclipse.jdt.ls.core.internal.managers.GradleProjectImporter.startSynchronization(GradleProjectImporter.java:128)
at org.eclipse.jdt.ls.core.internal.managers.GradleProjectImporter.importDir(GradleProjectImporter.java:90)
at org.eclipse.jdt.ls.core.internal.managers.GradleProjectImporter.lambda$0(GradleProjectImporter.java:82)
at java.util.ArrayList.forEach(ArrayList.java:1249)
at java.util.Collections$UnmodifiableCollection.forEach(Collections.java:1080)
at org.eclipse.jdt.ls.core.internal.managers.GradleProjectImporter.importToWorkspace(GradleProjectImporter.java:82)
at org.eclipse.jdt.ls.core.internal.managers.ProjectsManager.importProjects(ProjectsManager.java:105)
at org.eclipse.jdt.ls.core.internal.managers.ProjectsManager.access$1(ProjectsManager.java:99)
at org.eclipse.jdt.ls.core.internal.managers.ProjectsManager$1.run(ProjectsManager.java:93)
at org.eclipse.jdt.internal.core.BatchOperation.executeOperation(BatchOperation.java:39)
at org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:724)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2240)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2267)
at org.eclipse.jdt.core.JavaCore.run(JavaCore.java:5660)
at org.eclipse.jdt.core.JavaCore.run(JavaCore.java:5617)
at org.eclipse.jdt.ls.core.internal.managers.ProjectsManager.initializeProjects(ProjectsManager.java:86)
at org.eclipse.jdt.ls.core.internal.handlers.InitHandler$1.runInWorkspace(InitHandler.java:180)
at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:39)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1959)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:302)
at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:296)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1514)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:216)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1026)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:961)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1072)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1385)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1413)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1397)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1546)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1474)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
at org.gradle.wrapper.Download.downloadInternal(Download.java:66)
at org.gradle.wrapper.Download.download(Download.java:51)
at org.gradle.tooling.internal.consumer.DistributionInstaller$1.run(DistributionInstaller.java:128)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:397)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:302)
at sun.security.validator.Validator.validate(Validator.java:260)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1496)
... 15 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:392)
... 21 more

[Warn - 17:28:44] 2017-12-4 17:28:04 The workspace will exit with unsaved changes in this session.
[Error - 17:31:39] Connection to server got closed. Server will not be restarted.