elasticsearch 找不到实现连接器且名称与io.confluent.connect.elasticsearch匹配的任何类。独立运行的whle

连接器错误后停止时出错（org.apache.kafka.connect.cli.ConnectStandalone:117）

原因：org.apache.kafka.connect.errors.ConnectException:找不到任何实现连接器且名称与io.confluent.connect.elasticsearch.ElasticsearchSinkConnector匹配的类，可用的连接器有：PluginDesc{klass=class org.apache.kafka.connect.file.FileStreamSinkConnector，name='org.apache.kafka.connect.file.FileStreamSinkConnector'，version='2.8.0'，encodedVersion=2.8.0，type=sink，typeName='sink'，location='classpath'，PluginDesc{klass=class org.apache.kafka.connect.file.FileStreamSourceConnector，name='org.apache.kafka.connect.file.FileStreamSourceConnector'，version='2.8.0'，encodedVersion=2.8.0，type=source，typeName='source'，location='classpath'}，PluginDesc{klass=class org.apache.kafka.connect.MirrorCheckpointConnector，name='org.apache.kafka.connect.MirrorCheckpointConnector'，version='1'，encodedVersion=1，type=source，typeName='source'，location='classpath'}，PluginDesc{klass=class org.apache.kafka.connect.MirrorHeartbeatConnector，name='org.apache.kafka.connect.mirror.MirrorHeartbeatConnector'，version='1'，encodedVersion=1，type=source，typeName='source'，location='classpath'}，PluginDesc{klass=class org.apache.kafka.connect.MirrorSourceConnector