org.apache.nutch.metadata

Class Metadata

java.lang.Object

org.apache.nutch.metadata.Metadata

All Implemented Interfaces:

org.apache.hadoop.io.Writable, CreativeCommons, DublinCore, Feed, HttpHeaders, Nutch

Direct Known Subclasses:

SpellCheckedMetadata

public class Metadata
extends Object
implements org.apache.hadoop.io.Writable, CreativeCommons, DublinCore, HttpHeaders, Nutch, Feed

A multi-valued metadata container.

Field Summary

Fields inherited from interface org.apache.nutch.metadata.CreativeCommons

LICENSE_LOCATION, LICENSE_URL, WORK_TYPE

Fields inherited from interface org.apache.nutch.metadata.DublinCore

CONTRIBUTOR, COVERAGE, CREATOR, DATE, DESCRIPTION, FORMAT, IDENTIFIER, LANGUAGE, MODIFIED, PUBLISHER, RELATION, RIGHTS, SOURCE, SUBJECT, TITLE, TYPE

Fields inherited from interface org.apache.nutch.metadata.HttpHeaders

CONTENT_DISPOSITION, CONTENT_ENCODING, CONTENT_LANGUAGE, CONTENT_LENGTH, CONTENT_LOCATION, CONTENT_MD5, CONTENT_TYPE, LAST_MODIFIED, LOCATION, WRITABLE_CONTENT_TYPE

Fields inherited from interface org.apache.nutch.metadata.Nutch

CACHING_FORBIDDEN_ALL, CACHING_FORBIDDEN_CONTENT, CACHING_FORBIDDEN_KEY, CACHING_FORBIDDEN_NONE, CHAR_ENCODING_FOR_CONVERSION, FETCH_STATUS_KEY, FETCH_TIME_KEY, FIXED_INTERVAL_KEY, GENERATE_TIME_KEY, ORIGINAL_CHAR_ENCODING, PROTO_STATUS_KEY, REPR_URL_KEY, SCORE_KEY, SEGMENT_NAME_KEY, SIGNATURE_KEY, WRITABLE_FIXED_INTERVAL_KEY, WRITABLE_GENERATE_TIME_KEY, WRITABLE_PROTO_STATUS_KEY, WRITABLE_REPR_URL_KEY

Fields inherited from interface org.apache.nutch.metadata.Feed

FEED, FEED_AUTHOR, FEED_PUBLISHED, FEED_TAGS, FEED_UPDATED

Constructor Summary

Constructors

Constructor and Description
Metadata() Constructs a new, empty metadata.

Method Summary

Methods

Modifier and Type	Method and Description
void	add(String name, String value) Add a metadata name/value mapping.
void	clear() Remove all mappings from metadata.
boolean	equals(Object o)
String	get(String name) Get the value associated to a metadata name.
String[]	getValues(String name) Get the values associated to a metadata name.
boolean	isMultiValued(String name) Returns true if named value is multivalued.
String[]	names() Returns an array of the names contained in the metadata.
void	readFields(DataInput in)
void	remove(String name) Remove a metadata and all its associated values.
void	set(String name, String value) Set metadata name/value.
void	setAll(Properties properties) Copy All key-value pairs from properties.
int	size() Returns the number of metadata names in this metadata.
String	toString()
void	write(DataOutput out)

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Metadata

public Metadata()

Constructs a new, empty metadata.

Method Detail

isMultiValued

public boolean isMultiValued(String name)

Returns true if named value is multivalued.

Parameters:

name - name of metadata

Returns:

true is named value is multivalued, false if single value or null

names

public String[] names()

Returns an array of the names contained in the metadata.

Returns:

Metadata names

get

public String get(String name)

Get the value associated to a metadata name. If many values are assiociated to the specified name, then the first one is returned.

Parameters:

name - of the metadata.

Returns:

the value associated to the specified metadata name.

getValues

public String[] getValues(String name)

Get the values associated to a metadata name.

Parameters:

name - of the metadata.

Returns:

the values associated to a metadata name.

add

public void add(String name,
       String value)

Add a metadata name/value mapping. Add the specified value to the list of values associated to the specified metadata name.

Parameters:

name - the metadata name.

value - the metadata value.

setAll

public void setAll(Properties properties)

Copy All key-value pairs from properties.

Parameters:

properties - properties to copy from

set

public void set(String name,
       String value)

Set metadata name/value. Associate the specified value to the specified metadata name. If some previous values were associated to this name, they are removed.

Parameters:

name - the metadata name.

value - the metadata value.

remove

public void remove(String name)

Remove a metadata and all its associated values.

Parameters:

name - metadata name to remove

size

public int size()

Returns the number of metadata names in this metadata.

Returns:

number of metadata names

clear

public void clear()

Remove all mappings from metadata.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

write

public final void write(DataOutput out)
                 throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

readFields

public final void readFields(DataInput in)
                      throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException