xml 特殊字符 导致的 solr 数据导入异常

一、问题

最近开发那边反应 solr 的数据好像一个月没有更新了，登陆到 solr 的服务器，查看日志，有以下的报错日志。

org.apache.solr.handler.dataimport.DataImportHandlerException: Data Config problem: The reference to entity "xdm2" must end with the ';' delimiter.
	at org.apache.solr.handler.dataimport.DataImporter.loadDataConfig(DataImporter.java:220)
	at org.apache.solr.handler.dataimport.DataImporter.maybeReloadConfiguration(DataImporter.java:130)
	at org.apache.solr.handler.dataimport.DataImportHandler.handleRequestBody(DataImportHandler.java:175)
	at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:155)
	at org.apache.solr.core.SolrCore.execute(SolrCore.java:2102)
	at org.apache.solr.servlet.HttpSolrCall.execute(HttpSolrCall.java:654)
	at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:460)
	at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:257)
	at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:208)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215)
	at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
	at org.eclipse.jetty.server.Server.handle(Server.java:499)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:310)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)
	at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
	at java.lang.Thread.run(Thread.java:748)
Caused by: org.xml.sax.SAXParseException; systemId: solrres:/solr-data-config.xml; lineNumber: 8; columnNumber: 206; The reference to entity "xdm2" must end with the ';' delimiter.
	at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:203)
	at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(ErrorHandlerWrapper.java:177)
	at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:400)
	at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:327)
	at com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(XMLScanner.java:1472)
	at com.sun.org.apache.xerces.internal.impl.XMLScanner.scanAttributeValue(XMLScanner.java:913)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanAttribute(XMLNSDocumentScannerImpl.java:447)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:250)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2784)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:602)
	at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:505)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:841)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:770)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
	at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:243)
	at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:339)
	at org.apache.solr.handler.dataimport.DataImporter.loadDataConfig(DataImporter.java:211)

二、问题原因

根据报错内容，我们查看其中的配置文件 solr-data-config.xml 发现在 password 的字段里面有个特殊字符 &, 在 xml 中 & 是特殊字符，我们需要转义它让它正常显示为 & 。

三、问题解决

我们将 & 使用 & 来替代。然后触发重新导入即可。无需重启 solr , 使用对应的 api 接口进行触发导入。