Package org.apache.nutch.util

## Class AbstractChecker

- java.lang.Object
- - org.apache.hadoop.conf.Configured
  - - org.apache.nutch.util.AbstractChecker

- All Implemented Interfaces:
    `Configurable`, `Tool`
  Direct Known Subclasses:
    `CrawlDbReader`, `IndexingFiltersChecker`, `LinkDbReader`, `ParserChecker`, `URLFilterChecker`, `URLNormalizerChecker`

      public abstract class AbstractChecker
      extends Configured
      implements Tool

  Scaffolding class for the various Checker implementations. Can process cmdline input, stdin and TCP connections.
  Author:
    Jurian Broertjes

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected boolean` | `keepClientCnxOpen` |
    `protected boolean` | `stdin` |
    `protected int` | `tcpPort` |
    `protected String` | `usage` |

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `AbstractChecker()` |

  - ### Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `protected ProtocolOutput` | `getProtocolOutput​(String url, CrawlDatum datum, boolean checkRobotsTxt)` |
    `protected int` | `parseArgs​(String[] args, int i)` |
    `protected abstract int` | `process​(String line, StringBuilder output)` |
    `protected int` | `processSingle​(String input)` |
    `protected int` | `processStdin()` |
    `protected int` | `processTCP​(int tcpPort)` |
    `protected int` | `run()` |

    - ### Methods inherited from class org.apache.hadoop.conf.Configured

      `getConf, setConf`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

    - ### Methods inherited from interface org.apache.hadoop.conf.Configurable

      `getConf, setConf`

    - ### Methods inherited from interface org.apache.hadoop.util.Tool

      `run`

- - ### Field Detail

    - #### keepClientCnxOpen

          protected boolean keepClientCnxOpen

    - #### tcpPort

          protected int tcpPort

    - #### stdin

          protected boolean stdin

    - #### usage

          protected String usage

  - ### Constructor Detail

    - #### AbstractChecker

          public AbstractChecker()

  - ### Method Detail

    - #### process

          protected abstract int process​(String line,
                                         StringBuilder output)
                                  throws Exception

      Throws:
        `Exception`

    - #### parseArgs

          protected int parseArgs​(String[] args,
                                  int i)

    - #### run

          protected int run()
                     throws Exception

      Throws:
        `Exception`

    - #### processSingle

          protected int processSingle​(String input)
                               throws Exception

      Throws:
        `Exception`

    - #### processStdin

          protected int processStdin()
                              throws Exception

      Throws:
        `Exception`

    - #### processTCP

          protected int processTCP​(int tcpPort)
                            throws Exception

      Throws:
        `Exception`

    - #### getProtocolOutput

          protected ProtocolOutput getProtocolOutput​(String url,
                                                     CrawlDatum datum,
                                                     boolean checkRobotsTxt)
                                              throws Exception

      Throws:
        `Exception`