向stormcrawler添加tika解析器时，不会从该字段提取任何信息并存储在elasticsearch中。
es-爬虫.flux

includes:
  - resource: true
    file: "/crawler-default.yaml"
    override: false

  - resource: false
    file: "crawler-conf.yaml"
    override: true

  - resource: false
    file: "es-conf.yaml"
    override: true

spouts:
  - id: "spout"
    className: "com.digitalpebble.stormcrawler.elasticsearch.persistence.AggregationSpout"
    parallelism: 10

  - id: "filespout"
    className: "com.digitalpebble.stormcrawler.spout.FileSpout"
    parallelism: 1
    constructorArgs:
      - "."
      - "seeds.txt"
      - true

bolts:
  - id: "filter"
    className: "com.digitalpebble.stormcrawler.bolt.URLFilterBolt"
    parallelism: 1
  - id: "partitioner"
    className: "com.digitalpebble.stormcrawler.bolt.URLPartitionerBolt"
    parallelism: 1
  - id: "fetcher"
    className: "com.digitalpebble.stormcrawler.bolt.FetcherBolt"
    parallelism: 1
  - id: "sitemap"
    className: "com.digitalpebble.stormcrawler.bolt.SiteMapParserBolt"
    parallelism: 1
  - id: "parse"
    className: "com.digitalpebble.stormcrawler.bolt.JSoupParserBolt"
    parallelism: 1
  - id: "tika_redirection"
    className: "com.digitalpebble.stormcrawler.tika.RedirectionBolt"
    parallelism: 1
  - id: "tika_parser"
    className: "com.digitalpebble.stormcrawler.tika.ParserBolt"
    parallelism: 1
  - id: "index"
    className: "com.digitalpebble.stormcrawler.elasticsearch.bolt.IndexerBolt"
    parallelism: 1
  - id: "status"
    className: "com.digitalpebble.stormcrawler.elasticsearch.persistence.StatusUpdaterBolt"
    parallelism: 1
  - id: "status_metrics"
    className: "com.digitalpebble.stormcrawler.elasticsearch.metrics.StatusMetricsBolt"
    parallelism: 1

streams:
  - from: "spout"
    to: "partitioner"
    grouping:
      type: SHUFFLE

  - from: "spout"
    to: "status_metrics"
    grouping:
      type: SHUFFLE     

  - from: "partitioner"
    to: "fetcher"
    grouping:
      type: FIELDS
      args: ["key"]

  - from: "fetcher"
    to: "sitemap"
    grouping:
      type: LOCAL_OR_SHUFFLE

  - from: "sitemap"
    to: "parse"
    grouping:
      type: LOCAL_OR_SHUFFLE

  - from: "parse"
    to: "index"
    grouping:
      type: LOCAL_OR_SHUFFLE

  - from: "fetcher"
    to: "status"
    grouping:
      type: FIELDS
      args: ["url"]
      streamId: "status"

  - from: "sitemap"
    to: "status"
    grouping:
      type: FIELDS
      args: ["url"]
      streamId: "status"

  - from: "parse"
    to: "status"
    grouping:
      type: FIELDS
      args: ["url"]
      streamId: "status"

  - from: "parse"
    to: "tika_redirection"
    grouping:
      type: LOCAL_OR_SHUFFLE

  - from: "tika_redirection"
    to: "tika_parser"
    grouping:
      type: LOCAL_OR_SHUFFLE
      streamId: "tika"

  - from: "tika_parser"
    to: "index"
    grouping:
      type: LOCAL_OR_SHUFFLE

  - from: "tika_parser"
    to: "status"
    grouping:
      type: FIELDS
      args: ["url"]
      streamId: "status"

  - from: "index"
    to: "status"
    grouping:
      type: FIELDS
      args: ["url"]
      streamId: "status"

  - from: "filespout"
    to: "filter"
    grouping:
      type: FIELDS
      args: ["url"]
      streamId: "status"

  - from: "filter"
    to: "status"
    grouping:
      streamId: "status"
      type: CUSTOM
      customClass:
        className: "com.digitalpebble.stormcrawler.util.URLStreamGrouping"
        constructorArgs:
          - "byDomain"

我在crawler-conf.yaml中添加了以下设置：
爬虫-conf.yaml

parser.mimetype.whitelist:
    - application/.*pdf.*

  jsoup.treat.non.html.as.error: false

另外，我在运行拓扑时会发现以下日志：

16:27:29.867 [Thread-43-tika_parser-executor[22, 22]] INFO  c.d.s.t.ParserBolt - skipped_trimmed -> http://cds.iisc.ac.in/wp-content/uploads/DS256.2017.Storm_.Tutorial.pdf

我更喜欢从pdf中提取所有可能的字段，并使用数组存储页面中的信息，因此，在elasticsearch中，一个页面成为数组中的一个元素。