org.apache.lucene.search.suggest
Class Lookup

java.lang.Object
  extended by 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


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