org.apache.lucene.search.suggest
Class Lookup

java.lang.Object
  org.apache.lucene.search.suggest.Lookup

Direct Known Subclasses:

FSTLookup, JaspellLookup, TSTLookup

public abstract class Lookup
extends Object

Nested Class Summary

static class	Lookup.LookupPriorityQueue
static class	Lookup.LookupResult Result of a lookup.

Constructor Summary

Lookup()

Method Summary

abstract boolean	add(String key, Object value) Modify the lookup data by recording additional data.
void	build(Dictionary dict) Build lookup from a dictionary.
abstract void	build(TermFreqIterator tfit)
abstract Object	get(String key) Get value associated with a specific key.
abstract boolean	load(File storeDir) Discard current lookup data and load it from a previously saved copy.
abstract List<Lookup.LookupResult>	lookup(String key, boolean onlyMorePopular, int num) Look up a key and return possible completion for this key.
abstract boolean	store(File storeDir) Persist the constructed lookup data to a directory.

Methods inherited from class java.lang.Object

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

Constructor Detail

Lookup

public Lookup()

Method Detail

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 SortedTermFreqIteratorWrapper or UnsortedTermFreqIteratorWrapper in such case.

Throws:

IOException

build

public abstract void build(TermFreqIterator tfit)
                    throws IOException

Throws:

IOException

store

public abstract boolean store(File storeDir)
                       throws IOException

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

Parameters:

storeDir - directory where data can be stored.

Returns:

true if successful, false if unsuccessful or not supported.

Throws:

IOException - when fatal IO error occurs.

load

public abstract boolean load(File storeDir)
                      throws IOException

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

Parameters:

storeDir - directory where lookup data was stored.

Returns:

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

Throws:

IOException - when fatal IO error occurs.

lookup

public abstract List<Lookup.LookupResult> lookup(String 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)

add

public abstract boolean add(String key,
                            Object value)

Modify the lookup data by recording additional data. Optional operation.

Parameters:

key - new lookup key

value - value to associate with this key

Returns:

true if new key is added, false if it already exists or operation is not supported.

get

public abstract Object get(String key)

Get value associated with a specific key.

Parameters:

key - lookup key

Returns:

associated value