问题描述
我刚刚将 Android Studio 从 4.1.3 更新到 4.2。
现在，它找不到任何模拟器，甚至找不到我的手机。它显示一条消息“正在加载设备”。
此外，当我单击 AVD 管理器时，它不会打开。它向我显示了这个错误：
java.lang.NoClassDefFoundError: org/w3c/dom/ElementTraversal
at java.lang.classLoader.defineClass1(Native Method)
at java.lang.classLoader.defineClass(ClassLoader.java:763)
at java.lang.classLoader.defineClass(ClassLoader.java:642)
at com.intellij.util.lang.urlclassloader._defineClass(urlclassloader.java:419)
at com.intellij.util.lang.urlclassloader.defineClass(urlclassloader.java:411)
at com.intellij.util.lang.urlclassloader._findClass(urlclassloader.java:369)
at com.intellij.util.lang.urlclassloader.findClass(urlclassloader.java:355)
at java.lang.classLoader.loadClass(ClassLoader.java:424)
at java.lang.classLoader.loadClass(ClassLoader.java:357)
at org.apache.xerces.parsers.AbstractDOMParser.startDocument(UnkNown Source)
at org.apache.xerces.impl.dtd.XMLDTDValidator.startDocument(UnkNown Source)
at org.apache.xerces.impl.XMLDocumentScannerImpl.startEntity(UnkNown Source)
at org.apache.xerces.impl.XMLVersionDetector.startDocumentParsing(UnkNown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(UnkNown Source)
at org.apache.xerces.parsers.XML11Configuration.parse(UnkNown Source)
at org.apache.xerces.parsers.XMLParser.parse(UnkNown Source)
at org.apache.xerces.parsers.DOMParser.parse(UnkNown Source)
at org.apache.xerces.jaxp.DocumentBuilderImpl.parse(UnkNown Source)
at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:121)
at com.android.dvlib.DeviceSchema.getXmlSchemaVersion(DeviceSchema.java:398)
at com.android.sdklib.devices.DeviceParser.parseImpl(DeviceParser.java:496)
at com.android.sdklib.devices.DeviceParser.parse(DeviceParser.java:481)
at com.android.sdklib.devices.DeviceManager.initDefaultDevices(DeviceManager.java:287)
at com.android.sdklib.devices.DeviceManager.initDevicesLists(DeviceManager.java:265)
at com.android.sdklib.devices.DeviceManager.getDevice(DeviceManager.java:198)
at com.android.sdklib.internal.avd.AvdManager.parseAvdInfo(AvdManager.java:1451)
at com.android.sdklib.internal.avd.AvdManager.buildAvdList(AvdManager.java:1337)
at com.android.sdklib.internal.avd.AvdManager.<init>(AvdManager.java:402)
at com.android.sdklib.internal.avd.AvdManager.getInstance(AvdManager.java:443)
at com.android.tools.idea.avdmanager.AvdManagerConnection.initIfNecessary(AvdManagerConnection.java:211)
at com.android.tools.idea.avdmanager.AvdManagerConnection.getAvds(AvdManagerConnection.java:333)
at com.android.tools.idea.avdmanager.AvddisplayList.refreshAvds(AvddisplayList.java:230)
at com.android.tools.idea.avdmanager.AvddisplayList.<init>(AvddisplayList.java:194)
at com.android.tools.idea.avdmanager.AvdListDialog.<init>(AvdListDialog.java:43)
at org.jetbrains.android.actions.RunAndroidAvdManagerAction.openAvdManager(RunAndroidAvdManagerAction.java:74)
at org.jetbrains.android.actions.RunAndroidAvdManagerAction.actionPerformed(RunAndroidAvdManagerAction.java:65)
at com.intellij.openapi.actionSystem.ex.ActionUtil.performActionDumbAware(ActionUtil.java:282)
at com.intellij.openapi.actionSystem.ex.ActionUtil.performActionDumbAwareWithCallbacks(ActionUtil.java:276)
at com.intellij.openapi.actionSystem.impl.ActionButton.actionPerformed(ActionButton.java:182)
at com.intellij.openapi.actionSystem.impl.ActionButton.performAction(ActionButton.java:155)
at com.intellij.openapi.actionSystem.impl.ActionButton.processMouseEvent(ActionButton.java:439)
at java.awt.Component.processEvent(Component.java:6298)
at java.awt.Container.processEvent(Container.java:2236)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2294)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.Lightweightdispatcher.retargetMouseEvent(Container.java:4888)
at java.awt.Lightweightdispatcher.processMouseEvent(Container.java:4525)
at java.awt.Lightweightdispatcher.dispatchEvent(Container.java:4466)
at java.awt.Container.dispatchEventImpl(Container.java:2280)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at
操作系统：macOS Big Sur - 11.2.3
我已经尝试卸载 android studio 并重新安装。
我已经在 SDK 工具选项卡和 3 个不同的 SDK 平台上安装了所有东西。
解决方法
我遇到了同样的问题。最后我找到了以下解决方案：在 Preferences 文件夹（在我的 Mac 上 ~/Library/Application Support/Google/AndroidStudio4.2）中有一个指向 Java 8 版本的 studio.jdk 文件。我编辑了该文件，并将其替换为更新版本（在我的情况下为 /Library/Java/JavaVirtualMachines/jdk-14.0.2.jdk）。然后 avdmanager 开始在 Android Studio 4.2 中工作。
我已在 Google 的问题跟踪器上提交了以下问题：https://issuetracker.google.com/issues/187890146。如果您遇到此问题，请为它加星标。
,如果您添加 ANDROID_SDK_HOME 作为环境变量，则必须更改为 ANDROID_PREFS_ROOT。