java - 启动 google app engine java 后端时出现 org.jdom.input.JDOMParseException

Question

我想将现有的 Android 应用程序连接到 Google App Engine。我已经设置了一个端点。问题是每当我尝试启动后端时都会遇到异常。我尝试清除主文件夹中的缓存文件，但不起作用。异常是这样的:

Error:Internal error: (org.jdom.input.JDOMParseException) Error on line 1: Content is not allowed in prolog.
org.jdom.input.JDOMParseException: Error on line 1: Content is not allowed in prolog.
    at org.jdom.input.SAXBuilder.build(SAXBuilder.java:533)
    at org.jdom.input.SAXBuilder.build(SAXBuilder.java:946)
    at com.intellij.openapi.util.JDOMUtil.loadDocument(JDOMUtil.java:364)
    at com.intellij.openapi.util.JDOMUtil.loadDocument(JDOMUtil.java:342)
    at org.jetbrains.jps.model.serialization.JpsLoaderBase.loadRootElement(JpsLoaderBase.java:69)
    at org.jetbrains.jps.model.serialization.JpsLoaderBase.loadRootElement(JpsLoaderBase.java:40)
    at org.jetbrains.jps.model.serialization.JpsLoaderBase.loadComponents(JpsLoaderBase.java:52)
    at org.jetbrains.jps.model.serialization.JpsProjectLoader.loadFromDirectory(JpsProjectLoader.java:119)
    at org.jetbrains.jps.model.serialization.JpsProjectLoader.loadProject(JpsProjectLoader.java:98)
    at org.jetbrains.jps.model.serialization.impl.JpsSerializationManagerImpl.loadModel(JpsSerializationManagerImpl.java:41)
    at org.jetbrains.jps.cmdline.JpsModelLoaderImpl.loadModel(JpsModelLoaderImpl.java:45)
    at org.jetbrains.jps.cmdline.BuildRunner.load(BuildRunner.java:71)
    at org.jetbrains.jps.cmdline.BuildSession.runBuild(BuildSession.java:198)
    at org.jetbrains.jps.cmdline.BuildSession.run(BuildSession.java:113)
    at org.jetbrains.jps.cmdline.BuildMain$MyMessageHandler$1.run(BuildMain.java:157)
    at org.jetbrains.jps.service.impl.SharedThreadPoolImpl$1.run(SharedThreadPoolImpl.java:41)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:441)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:368)
    at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1436)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:999)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:117)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:649)
    at org.jdom.input.SAXBuilder.build(SAXBuilder.java:518)
    ... 20 more
Caused by: org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
    at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:441)
    at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:368)
    at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1436)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:999)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:606)
    at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:117)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:848)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:777)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1213)
    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:649)
    at org.jdom.input.SAXBuilder.build(SAXBuilder.java:518)
    at org.jdom.input.SAXBuilder.build(SAXBuilder.java:946)
    at com.intellij.openapi.util.JDOMUtil.loadDocument(JDOMUtil.java:364)
    at com.intellij.openapi.util.JDOMUtil.loadDocument(JDOMUtil.java:342)
    at org.jetbrains.jps.model.serialization.JpsLoaderBase.loadRootElement(JpsLoaderBase.java:69)
    at org.jetbrains.jps.model.serialization.JpsLoaderBase.loadRootElement(JpsLoaderBase.java:40)
    at org.jetbrains.jps.model.serialization.JpsLoaderBase.loadComponents(JpsLoaderBase.java:52)
    at org.jetbrains.jps.model.serialization.JpsProjectLoader.loadFromDirectory(JpsProjectLoader.java:119)
    at org.jetbrains.jps.model.serialization.JpsProjectLoader.loadProject(JpsProjectLoader.java:98)
    at org.jetbrains.jps.model.serialization.impl.JpsSerializationManagerImpl.loadModel(JpsSerializationManagerImpl.java:41)
    at org.jetbrains.jps.cmdline.JpsModelLoaderImpl.loadModel(JpsModelLoaderImpl.java:45)
    at org.jetbrains.jps.cmdline.BuildRunner.load(BuildRunner.java:71)
    at org.jetbrains.jps.cmdline.BuildSession.runBuild(BuildSession.java:198)
    at org.jetbrains.jps.cmdline.BuildSession.run(BuildSession.java:113)
    at org.jetbrains.jps.cmdline.BuildMain$MyMessageHandler$1.run(BuildMain.java:157)
    at org.jetbrains.jps.service.impl.SharedThreadPoolImpl$1.run(SharedThreadPoolImpl.java:41)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

Answer 1

您提供给 JDOM(以及 Xerces)的流不包含 XML，它包含其他内容。

造成这种情况的典型原因是:

1. 您正在从发送压缩数据的 URL/HTTP 服务器提取数据
2. Base64 编码数据
3. 包含非 200 响应，例如页面重定向或某些不打算解析为 XML 的响应，而是打算在 HTTP 协议(protocol)级别进行处理。
4. 您没有传递您认为传递的流

您建议的操作过程是转储实际流内容，而不是尝试将其解析为 XML，并查看您正在向解析器提供什么(并确定为什么会出现这种情况) .