MESSAGE The workspace exited with unsaved changes in the previous session; refreshing workspace to r

!SESSION 2015-01-19 20:59:03.289 -----------------------------------------------

eclipse.buildId=I20120608-1400

java.version=1.6.0_45

java.vendor=Sun Microsystems Inc.

BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=zh_CN

Framework arguments:  -product org.eclipse.epp.package.java.product

Command-line arguments:  -os win32 -ws win32 -arch x86 -product org.eclipse.epp.package.java.product

!ENTRY org.eclipse.core.resources 2 10035 2015-01-19 20:59:06.284

!MESSAGE The workspace exited with unsaved changes in the previous session; refreshing workspace to recover changes.

!ENTRY org.eclipse.equinox.preferences 4 2 2015-01-19 20:59:08.593

!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.equinox.preferences".

!STACK 0

java.lang.ExceptionInInitializerError
at org.eclipse.wb.internal.core.preferences.PreferenceInitializer.initializeDefaultPreferences(PreferenceInitializer.java:50)
at org.eclipse.core.internal.preferences.PreferenceServiceRegistryHelper$1.run(PreferenceServiceRegistryHelper.java:300)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.internal.preferences.PreferenceServiceRegistryHelper.runInitializer(PreferenceServiceRegistryHelper.java:303)
at org.eclipse.core.internal.preferences.PreferenceServiceRegistryHelper.applyRuntimeDefaults(PreferenceServiceRegistryHelper.java:131)
at org.eclipse.core.internal.preferences.PreferencesService.applyRuntimeDefaults(PreferencesService.java:368)
at org.eclipse.core.internal.preferences.DefaultPreferences.applyRuntimeDefaults(DefaultPreferences.java:166)
at org.eclipse.core.internal.preferences.DefaultPreferences.load(DefaultPreferences.java:237)
at org.eclipse.core.internal.preferences.EclipsePreferences.create(EclipsePreferences.java:410)
at org.eclipse.core.internal.preferences.EclipsePreferences.internalNode(EclipsePreferences.java:663)
at org.eclipse.core.internal.preferences.EclipsePreferences.node(EclipsePreferences.java:805)
at org.eclipse.core.internal.preferences.AbstractScope.getNode(AbstractScope.java:38)
at org.eclipse.core.runtime.preferences.DefaultScope.getNode(DefaultScope.java:76)
at org.eclipse.ui.preferences.ScopedPreferenceStore.getDefaultPreferences(ScopedPreferenceStore.java:250)
at org.eclipse.ui.preferences.ScopedPreferenceStore.getPreferenceNodes(ScopedPreferenceStore.java:285)
at org.eclipse.ui.preferences.ScopedPreferenceStore.internalGet(ScopedPreferenceStore.java:475)
at org.eclipse.ui.preferences.ScopedPreferenceStore.getBoolean(ScopedPreferenceStore.java:387)
at org.eclipse.wb.internal.core.editor.describer.JavaSourceUiDescriber.isGUISource(JavaSourceUiDescriber.java:65)
at org.eclipse.wb.internal.core.editor.describer.JavaSourceUiDescriber.describe(JavaSourceUiDescriber.java:52)
at org.eclipse.core.internal.content.ContentTypeCatalog.describe(ContentTypeCatalog.java:218)
at org.eclipse.core.internal.content.ContentTypeCatalog.collectMatchingByContents(ContentTypeCatalog.java:190)
at org.eclipse.core.internal.content.ContentTypeCatalog.internalFindContentTypesFor(ContentTypeCatalog.java:403)
at org.eclipse.core.internal.content.ContentTypeCatalog.internalFindContentTypesFor(ContentTypeCatalog.java:450)
at org.eclipse.core.internal.content.ContentTypeCatalog.getDescriptionFor(ContentTypeCatalog.java:346)
at org.eclipse.core.internal.content.ContentTypeCatalog.getDescriptionFor(ContentTypeCatalog.java:360)
at org.eclipse.core.internal.content.ContentTypeMatcher.getDescriptionFor(ContentTypeMatcher.java:86)
at org.eclipse.core.internal.resources.ContentDescriptionManager.readDescription(ContentDescriptionManager.java:445)
at org.eclipse.core.internal.resources.ContentDescriptionManager.getDescriptionFor(ContentDescriptionManager.java:355)
at org.eclipse.core.internal.resources.File.internalGetCharset(File.java:246)
at org.eclipse.core.internal.resources.File.getCharset(File.java:207)
at org.eclipse.core.internal.resources.File.getCharset(File.java:194)
at org.eclipse.jdt.internal.core.util.Util.getResourceContentsAsCharArray(Util.java:1156)
at org.eclipse.jdt.internal.core.builder.SourceFile.getContents(SourceFile.java:79)
at org.eclipse.jdt.internal.compiler.ReadManager.run(ReadManager.java:173)
at java.lang.Thread.run(Unknown Source)

Caused by: org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(SWT.java:4361)
at org.eclipse.swt.SWT.error(SWT.java:4276)
at org.eclipse.swt.SWT.error(SWT.java:4247)
at org.eclipse.swt.widgets.Display.error(Display.java:1258)
at org.eclipse.swt.widgets.Display.checkDevice(Display.java:764)
at org.eclipse.swt.widgets.Display.getSystemFont(Display.java:2459)
at org.eclipse.jface.preference.PreferenceConverter.<clinit>(PreferenceConverter.java:84)
... 35 more

!ENTRY org.eclipse.equinox.preferences 4 2 2015-01-19 20:59:08.608

!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.equinox.preferences".

!STACK 0

java.lang.NoClassDefFoundError: Could not initialize class org.eclipse.jface.preference.PreferenceConverter
at org.eclipse.wb.internal.core.preferences.PreferenceInitializer.initializeDefaultPreferences(PreferenceInitializer.java:50)
at org.eclipse.core.internal.preferences.PreferenceServiceRegistryHelper$1.run(PreferenceServiceRegistryHelper.java:300)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.internal.preferences.PreferenceServiceRegistryHelper.runInitializer(PreferenceServiceRegistryHelper.java:303)
at org.eclipse.core.internal.preferences.PreferenceServiceRegistryHelper.applyRuntimeDefaults(PreferenceServiceRegistryHelper.java:131)
at org.eclipse.core.internal.preferences.PreferencesService.applyRuntimeDefaults(PreferencesService.java:368)
at org.eclipse.core.internal.preferences.DefaultPreferences.applyRuntimeDefaults(DefaultPreferences.java:166)
at org.eclipse.core.internal.preferences.DefaultPreferences.load(DefaultPreferences.java:237)
at org.eclipse.core.internal.preferences.EclipsePreferences.create(EclipsePreferences.java:410)
at org.eclipse.core.internal.preferences.EclipsePreferences.internalNode(EclipsePreferences.java:663)
at org.eclipse.core.internal.preferences.EclipsePreferences.node(EclipsePreferences.java:805)
at org.eclipse.core.internal.preferences.Abst
c1db
ractScope.getNode(AbstractScope.java:38)
at org.eclipse.core.runtime.preferences.DefaultScope.getNode(DefaultScope.java:76)
at org.eclipse.ui.preferences.ScopedPreferenceStore.getDefaultPreferences(ScopedPreferenceStore.java:250)
at org.eclipse.ui.preferences.ScopedPreferenceStore.getPreferenceNodes(ScopedPreferenceStore.java:285)
at org.eclipse.ui.preferences.ScopedPreferenceStore.internalGet(ScopedPreferenceStore.java:475)
at org.eclipse.ui.preferences.ScopedPreferenceStore.getBoolean(ScopedPreferenceStore.java:387)
at org.eclipse.wb.internal.core.editor.describer.JavaSourceUiDescriber.isGUISource(JavaSourceUiDescriber.java:65)
at org.eclipse.wb.internal.core.editor.describer.JavaSourceUiDescriber.describe(JavaSourceUiDescriber.java:52)
at org.eclipse.core.internal.content.ContentTypeCatalog.describe(ContentTypeCatalog.java:218)
at org.eclipse.core.internal.content.ContentTypeCatalog.collectMatchingByContents(ContentTypeCatalog.java:190)
at org.eclipse.core.internal.content.ContentTypeCatalog.internalFindContentTypesFor(ContentTypeCatalog.java:403)
at org.eclipse.core.internal.content.ContentTypeCatalog.internalFindContentTypesFor(ContentTypeCatalog.java:450)
at org.eclipse.core.internal.content.ContentTypeCatalog.getDescriptionFor(ContentTypeCatalog.java:346)
at org.eclipse.core.internal.content.ContentTypeCatalog.getDescriptionFor(ContentTypeCatalog.java:360)
at org.eclipse.core.internal.content.ContentTypeMatcher.getDescriptionFor(ContentTypeMatcher.java:86)
at org.eclipse.core.internal.resources.ContentDescriptionManager.readDescription(ContentDescriptionManager.java:445)
at org.eclipse.core.internal.resources.ContentDescriptionManager.getDescriptionFor(ContentDescriptionManager.java:355)
at org.eclipse.core.internal.resources.File.internalGetCharset(File.java:246)
at org.eclipse.core.internal.resources.File.getCharset(File.java:207)
at org.eclipse.core.internal.resources.File.getCharset(File.java:194)
at org.eclipse.jdt.internal.core.util.Util.getResourceContentsAsCharArray(Util.java:1156)
at org.eclipse.jdt.internal.core.builder.SourceFile.getContents(SourceFile.java:79)
at org.eclipse.jdt.internal.compiler.ReadManager.run(ReadManager.java:173)
at java.lang.Thread.run(Unknown Source)

!ENTRY org.eclipse.osgi 4 0 2015-01-19 20:59:09.700

!MESSAGE Application error

!STACK 1

java.lang.NoClassDefFoundError: Could not initialize class org.eclipse.jface.preference.PreferenceConverter
at org.eclipse.ui.internal.themes.ThemeElementHelper.installFont(ThemeElementHelper.java:103)
at org.eclipse.ui.internal.themes.ThemeElementHelper.populateRegistry(ThemeElementHelper.java:59)
at org.eclipse.ui.internal.Workbench$27.runWithException(Workbench.java:1550)
at org.eclipse.ui.internal.StartupThreading$StartupRunnable.run(StartupThreading.java:31)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4144)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3761)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2478)
at org.eclipse.ui.internal.Workbench.access$7(Workbench.java:2386)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:583)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:540)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:353)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
at org.eclipse.equinox.launcher.Main.run(Main.java:1438)

I solve the problem like this:

workspace/.metadata/.plugins/org.eclipse.core.resources/.snap

delete .snap.

then import your project again

have a good time.