当我使用以下命令从Ubuntu Nutch 1.15开始爬网时：
/usr/local/nutch/bin/crawl --i -s urls/seed.txt crawldb 5
然后它开始运行，并且出现此错误：
ERROR indexer.IndexingJob - Indexer: java.lang.RuntimeException: org.apache.nutch.plugin.PluginRuntimeException: java.lang.ClassNotFoundException: org.apache.nutch.indexwriter.solr.SolrIndexWriter
at org.apache.nutch.indexer.IndexWriters.<init>(IndexWriters.java:103)
at org.apache.nutch.indexer.IndexWriters.lambda$get$0(IndexWriters.java:57)
at org.apache.nutch.indexer.IndexWriters$$Lambda$9/9190301.apply(Unknown Source)
at java.util.Map.computeIfAbsent(Map.java:957)
at org.apache.nutch.indexer.IndexWriters.get(IndexWriters.java:57)
at org.apache.nutch.indexer.IndexingJob.index(IndexingJob.java:123)
at org.apache.nutch.indexer.IndexingJob.run(IndexingJob.java:235)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.nutch.indexer.IndexingJob.main(IndexingJob.java:244)
Caused by: org.apache.nutch.plugin.PluginRuntimeException: java.lang.ClassNotFoundException: org.apache.nutch.indexwriter.solr.SolrIndexWriter
at org.apache.nutch.plugin.Extension.getExtensionInstance(Extension.java:167)
at org.apache.nutch.indexer.IndexWriters.<init>(IndexWriters.java:94)
... 8 more
Caused by: java.lang.ClassNotFoundException: org.apache.nutch.indexwriter.solr.SolrIndexWriter
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.apache.nutch.plugin.PluginClassLoader.loadClassFromSystem(PluginClassLoader.java:104)
at org.apache.nutch.plugin.PluginClassLoader.loadClassFromParent(PluginClassLoader.java:92)
at org.apache.nutch.plugin.PluginClassLoader.loadClass(PluginClassLoader.java:72)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.apache.nutch.plugin.PluginRepository.getCachedClass(PluginRepository.java:332)
at org.apache.nutch.plugin.Extension.getExtensionInstance(Extension.java:156)
... 9 more
我想索引Solr 7.5
提前谢谢！