Package org.apache.nutch.crawl

Class Injector

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.nutch.util.NutchTool

org.apache.nutch.crawl.Injector

All Implemented Interfaces:

Configurable, Tool

public class Injector
extends NutchTool
implements Tool

Injector takes a flat text file of URLs (or a folder containing text files) and merges ("injects") these URLs into the CrawlDb. Useful for bootstrapping a Nutch crawl. The URL files contain one URL per line, optionally followed by custom metadata separated by tabs with the metadata key separated from the corresponding value by '='.

Note, that some metadata keys are reserved:

nutch.score

allows to set a custom score for a specific URL

nutch.fetchInterval

allows to set a custom fetch interval for a specific URL

nutch.fetchInterval.fixed

allows to set a custom fetch interval for a specific URL that is not changed by AdaptiveFetchSchedule

Example:

  http://www.nutch.org/ \t nutch.score=10 \t nutch.fetchInterval=2592000 \t userType=open_source
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Injector.InjectMapper	InjectMapper reads the CrawlDb seeds are injected into the plain-text seed files and parses each line into the URL and metadata.
static class	Injector.InjectReducer	Combine multiple new entries for a url.

Field Summary

Fields

Modifier and Type	Field	Description
static String	nutchFetchIntervalMDName	metadata key reserved for setting a custom fetchInterval for a specific URL
static String	nutchFixedFetchIntervalMDName	metadata key reserved for setting a fixed custom fetchInterval for a specific URL
static String	nutchScoreMDName	metadata key reserved for setting a custom score for a specific URL
static final String	URL_FILTER_NORMALIZE_ALL	property to pass value of command-line option -filterNormalizeAll to mapper

Fields inherited from class org.apache.nutch.util.NutchTool

currentJob, currentJobNum, numJobs, results, status

Constructor Summary

Constructors

Constructor	Description
Injector()
Injector(Configuration conf)

Method Summary

Modifier and Type	Method	Description
void	inject(Path crawlDb, Path urlDir)
void	inject(Path crawlDb, Path urlDir, boolean overwrite, boolean update)
void	inject(Path crawlDb, Path urlDir, boolean overwrite, boolean update, boolean normalize, boolean filter, boolean filterNormalizeAll)
static void	main(String[] args)
int	run(String[] args)
Map<String,Object>	run(Map<String,Object> args, String crawlId)	Programmatic entry point for NutchTool callers.
void	usage()

Methods inherited from class org.apache.nutch.util.NutchTool

getProgress, getStatus, killJob, setConf, stopJob

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

getConf

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

Field Details

URL_FILTER_NORMALIZE_ALL

public static final String URL_FILTER_NORMALIZE_ALL

property to pass value of command-line option -filterNormalizeAll to mapper

See Also:

• Constant Field Values

nutchScoreMDName

public static String nutchScoreMDName

metadata key reserved for setting a custom score for a specific URL

nutchFetchIntervalMDName

public static String nutchFetchIntervalMDName

metadata key reserved for setting a custom fetchInterval for a specific URL

nutchFixedFetchIntervalMDName

public static String nutchFixedFetchIntervalMDName

metadata key reserved for setting a fixed custom fetchInterval for a specific URL

Constructor Details

Injector

public Injector()

Injector

public Injector(Configuration conf)

Method Details

inject

public void inject(Path crawlDb,
 Path urlDir)
            throws IOException,
ClassNotFoundException,
InterruptedException

Throws:

IOException

ClassNotFoundException

InterruptedException

inject

public void inject(Path crawlDb,
 Path urlDir,
 boolean overwrite,
 boolean update)
            throws IOException,
ClassNotFoundException,
InterruptedException

Throws:

IOException

ClassNotFoundException

InterruptedException

inject

public void inject(Path crawlDb,
 Path urlDir,
 boolean overwrite,
 boolean update,
 boolean normalize,
 boolean filter,
 boolean filterNormalizeAll)
            throws IOException,
ClassNotFoundException,
InterruptedException

Throws:

IOException

ClassNotFoundException

InterruptedException

usage

public void usage()

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception

run

public int run(String[] args)
        throws Exception

Specified by:

run in interface Tool

Throws:

Exception

run

public Map<String,Object> run(Map<String,Object> args,
 String crawlId)
                       throws Exception

Programmatic entry point for NutchTool callers.

Specified by:

run in class NutchTool

Parameters:

args - a Map of arguments to be run with the tool

crawlId - a crawl identifier to associate with the tool invocation

Returns:

Map results object if tool executes successfully otherwise null

Throws:

Exception - if there is an error during the tool execution