Package org.apache.lucene.search.suggest

Class Lookup

java.lang.Object

org.apache.lucene.search.suggest.Lookup

Direct Known Subclasses:

AnalyzingInfixSuggester, AnalyzingSuggester, FreeTextSuggester, FSTCompletionLookup, JaspellLookup, TSTLookup, WFSTCompletionLookup

public abstract class Lookup
extends Object

Simple Lookup interface for CharSequence suggestions.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	Lookup.LookupPriorityQueue	A PriorityQueue collecting a fixed size of high priority Lookup.LookupResult
static final class	Lookup.LookupResult	Result of a lookup.

Field Summary

Fields

Modifier and Type	Field	Description
static final Comparator<CharSequence>	CHARSEQUENCE_COMPARATOR	A simple char-by-char comparator for CharSequence

Constructor Summary

Constructors

Constructor	Description
Lookup()	Sole constructor.

Method Summary

Modifier and Type	Method	Description
void	build(Dictionary dict)	Build lookup from a dictionary.
abstract void	build(InputIterator inputIterator)	Builds up a new internal Lookup representation based on the given InputIterator.
abstract long	getCount()	Get the number of entries the lookup was built with
boolean	load(InputStream input)	Calls load(DataInput) after converting InputStream to DataInput
abstract boolean	load(DataInput input)	Discard current lookup data and load it from a previously saved copy.
abstract List<Lookup.LookupResult>	lookup(CharSequence key, boolean onlyMorePopular, int num)	Look up a key and return possible completion for this key.
abstract long	sizeInBytes()	Get the size of the underlying lookup implementation in memory
boolean	store(OutputStream output)	Calls store(DataOutput) after converting OutputStream to DataOutput
abstract boolean	store(DataOutput output)	Persist the constructed lookup data to a directory.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

CHARSEQUENCE_COMPARATOR

public static final Comparator<CharSequence> CHARSEQUENCE_COMPARATOR

A simple char-by-char comparator for CharSequence

Constructor Details

Lookup

public Lookup()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Details

build

public void build(Dictionary dict)
           throws IOException

Build lookup from a dictionary. Some implementations may require sorted or unsorted keys from the dictionary's iterator - use SortedInputIterator or UnsortedInputIterator in such case.

Throws:

IOException

load

public boolean load(InputStream input)
             throws IOException

Calls load(DataInput) after converting InputStream to DataInput

Throws:

IOException

store

public boolean store(OutputStream output)
              throws IOException

Calls store(DataOutput) after converting OutputStream to DataOutput

Throws:

IOException

getCount

public abstract long getCount()

Get the number of entries the lookup was built with

Returns:

total number of suggester entries

build

public abstract void build(InputIterator inputIterator)
                    throws IOException

Builds up a new internal Lookup representation based on the given InputIterator. The implementation might re-sort the data internally.

Throws:

IOException

lookup

public abstract List<Lookup.LookupResult> lookup(CharSequence key,
 boolean onlyMorePopular,
 int num)

Look up a key and return possible completion for this key.

Parameters:

key - lookup key. Depending on the implementation this may be a prefix, misspelling, or even infix.

onlyMorePopular - return only more popular results

num - maximum number of results to return

Returns:

a list of possible completions, with their relative weight (e.g. popularity)

store

public abstract boolean store(DataOutput output)
                       throws IOException

Persist the constructed lookup data to a directory. Optional operation.

Parameters:

output - DataOutput to write the data to.

Returns:

true if successful, false if unsuccessful or not supported.

Throws:

IOException - when fatal IO error occurs.

load

public abstract boolean load(DataInput input)
                      throws IOException

Discard current lookup data and load it from a previously saved copy. Optional operation.

Parameters:

input - the DataInput to load the lookup data.

Returns:

true if completed successfully, false if unsuccessful or not supported.

Throws:

IOException - when fatal IO error occurs.

sizeInBytes

public abstract long sizeInBytes()

Get the size of the underlying lookup implementation in memory

Returns:

ram size of the lookup implementation in bytes