Java ApacheNutch2.3.1插件不起作用

我必须提取Apache Nutch 2.3.1默认情况下未提供的爬网数据的一些元数据信息。为此，我必须编写一个插件。为了学习的目的，我把它作为出发点。我知道本教程适用于1.x版本。我已经更改了所有必需的类，并成功地构建了它。以下是我遵循的步骤

创建一个类似$NUTCH_HOME/src/plugin/myPlugin的目录

将索引元数据复制到我的插件中，并创建一个文件myField.java cp-r索引元数据/*myPlugin/

目录列表应该是

plugin/myplgin/plugin.xml应该是这样的

我还在solr模式中添加了字段pageLength。根据我的期望，应该有一个新的字段pageLength和适当的值，但solr中没有字段

问题在哪里？这是一个简单的玩具例子。 这是索引步骤的nutch日志文件（hadoop.log）输出

2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: content dest: content
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: title dest: title
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: host dest: host
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: batchId dest: batchId
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: boost dest: boost
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: digest dest: digest
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: tstamp dest: tstamp
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: pageLength dest: pageLength
2016-07-26 16:53:26,140 INFO  solr.SolrIndexWriter - Total 1 document is added.
2016-07-26 16:53:26,140 INFO  indexer.IndexingJob - IndexingJob: done.

我如何确认插件是由nutch加载的？

---

第二，在我将Nutch插件配置为Nutch进行爬行之前，有没有办法测试它？

尝试更改plugin.xml中的扩展id。将其更改为“org.apache.nutch.indexer.AddField”，并重新构建nutch

<extension id="org.apache.nutch.indexer.AddField"
       name="Add Field to Index"
       point="org.apache.nutch.indexer.IndexingFilter">
     <implementation id="myPlugin"
         class="org.apache.nutch.indexer.AddField"/>
</extension>

我认为这应该解决问题

也只是为了验证控件是否进入插件类，或者是否在代码中添加一些信息日志，如

LOG.info（“从插件打印”）
若您能够在hadoop.log中看到这些日志，那个就意味着控制权将进入插件类

<?xml version="1.0" encoding="UTF-8"?>
<project name="myPlugin" default="jar">
  <import file="../build-plugin.xml"/>
</project>

<property>
  <name>plugin.includes</name>
  <value>plugin-1|plugin-2|myPlugin</value>
  <description>Added myPlugin</description>
</property>

<field name="pageLength" type="long" stored="true" indexed="true"/>
<field dest="pageLength" source="pageLength"/>

Active IndexWriters :
SOLRIndexWriter
    solr.server.url : URL of the SOLR instance (mandatory)
    solr.commit.size : buffer size when sending to SOLR (default 1000)
    solr.mapping.file : name of the mapping file for fields (default solrindex-mapping.xml)
    solr.auth : use authentication (default false)
    solr.auth.username : username for authentication
    solr.auth.password : password for authentication    
IndexingJob: done.

2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: content dest: content
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: title dest: title
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: host dest: host
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: batchId dest: batchId
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: boost dest: boost
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: digest dest: digest
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: tstamp dest: tstamp
2016-07-26 16:53:25,649 INFO  solr.SolrMappingReader - source: pageLength dest: pageLength
2016-07-26 16:53:26,140 INFO  solr.SolrIndexWriter - Total 1 document is added.
2016-07-26 16:53:26,140 INFO  indexer.IndexingJob - IndexingJob: done.

<extension id="org.apache.nutch.indexer.AddField"
       name="Add Field to Index"
       point="org.apache.nutch.indexer.IndexingFilter">
     <implementation id="myPlugin"
         class="org.apache.nutch.indexer.AddField"/>
</extension>