错误信息截图：
2018-08-02 07:56:17.527 INFO (qtp817348612-15) [ x:mysql2solr] o.a.s.m.r.SolrJmxReporter Closing reporter [org.apache.solr.metrics.reporters.SolrJmxReporter@47d9861c: rootName = null, domain = solr.core.mysql2solr, service url = null, agent id = null] for registry solr.core.mysql2solr / com.codahale.metrics.MetricRegistry@7b867df
2018-08-02 07:56:17.661 ERROR (qtp817348612-15) [ x:mysql2solr] o.a.s.h.RequestHandlerBase org.apache.solr.common.SolrException: Error CREATEing SolrCore 'mysql2solr': Unable to create core [mysql2solr] Caused by: solr.DataImportHandler
at org.apache.solr.core.CoreContainer.create(CoreContainer.java:1084)
at org.apache.solr.handler.admin.CoreAdminOperation.lambda$static$0(CoreAdminOperation.java:94)
at org.apache.solr.handler.admin.CoreAdminOperation.execute(CoreAdminOperation.java:380)
at org.apache.solr.handler.admin.CoreAdminHandler$CallInfo.call(CoreAdminHandler.java:395)
at org.apache.solr.handler.admin.CoreAdminHandler.handleRequestBody(CoreAdminHandler.java:180)
at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199)
at org.apache.solr.servlet.HttpSolrCall.handleAdmin(HttpSolrCall.java:734)
at org.apache.solr.servlet.HttpSolrCall.handleAdminRequest(HttpSolrCall.java:715)
at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:496)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:377)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:323)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1634)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1253)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1155)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:219)
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:126)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:335)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:531)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102)
at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:118)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:333)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:310)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:168)
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:126)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:366)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:760)
at org.eclipse.jetty.util.thread.QueuedThreadPool$2.run(QueuedThreadPool.java:678)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.apache.solr.common.SolrException: Unable to create core [mysql2solr]
at org.apache.solr.core.CoreContainer.createFromDescriptor(CoreContainer.java:1156)
at org.apache.solr.core.CoreContainer.create(CoreContainer.java:1045)
... 44 more
Caused by: org.apache.solr.common.SolrException: Error loading class 'solr.DataImportHandler'
at org.apache.solr.core.SolrCore.<init>(SolrCore.java:1012)
at org.apache.solr.core.SolrCore.<init>(SolrCore.java:867)
at org.apache.solr.core.CoreContainer.createFromDescriptor(CoreContainer.java:1135)
... 45 more
Caused by: org.apache.solr.common.SolrException: Error loading class 'solr.DataImportHandler'
at org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:557)
at org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:488)
at org.apache.solr.core.SolrCore.createInstance(SolrCore.java:790)
at org.apache.solr.core.PluginBag.createPlugin(PluginBag.java:141)
at org.apache.solr.core.PluginBag.init(PluginBag.java:277)
at org.apache.solr.core.RequestHandlers.initHandlersFromConfig(RequestHandlers.java:130)
at org.apache.solr.core.SolrCore.<init>(SolrCore.java:970)
... 47 more
Caused by: java.lang.ClassNotFoundException: solr.DataImportHandler
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.net.FactoryURLClassLoader.loadClass(URLClassLoader.java:814)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:541)
... 53 more原因：因为启动 Jetty 的时候缺少了相关依赖包。
解决办法：将 solr-8.1.0/distdist 目录下的 solr-dataimporthandler-8.1.0.jar 文件复制到 apache-tomcat-8.0.47/webapps/solr/WEB-INF/lib 目录下，然后重启 Solr 即可解决。
solr-8.1.0 ：下载solr-8.1.0源码
apache-tomcat-8.0.47：部署solr 的tomcat 服务器