Package org.apache.lucene.search.suggest
Class Lookup
- java.lang.Object
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- org.apache.lucene.search.suggest.Lookup
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- All Implemented Interfaces:
Accountable
- Direct Known Subclasses:
AnalyzingInfixSuggester
,AnalyzingSuggester
,FreeTextSuggester
,FSTCompletionLookup
,TSTLookup
,WFSTCompletionLookup
public abstract class Lookup extends Object implements Accountable
Simple Lookup interface forCharSequence
suggestions.- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
Lookup.LookupPriorityQueue
APriorityQueue
collecting a fixed size of high priorityLookup.LookupResult
static class
Lookup.LookupResult
Result of a lookup.
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Field Summary
Fields Modifier and Type Field Description static Comparator<CharSequence>
CHARSEQUENCE_COMPARATOR
A simple char-by-char comparator forCharSequence
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Fields inherited from interface org.apache.lucene.util.Accountable
NULL_ACCOUNTABLE
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Constructor Summary
Constructors Constructor Description Lookup()
Sole constructor.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description void
build(Dictionary dict)
Build lookup from a dictionary.abstract void
build(InputIterator inputIterator)
Builds up a new internalLookup
representation based on the givenInputIterator
.abstract long
getCount()
Get the number of entries the lookup was built withboolean
load(InputStream input)
abstract boolean
load(DataInput input)
Discard current lookup data and load it from a previously saved copy.List<Lookup.LookupResult>
lookup(CharSequence key, boolean onlyMorePopular, int num)
Look up a key and return possible completion for this key.abstract List<Lookup.LookupResult>
lookup(CharSequence key, Set<BytesRef> contexts, boolean onlyMorePopular, int num)
Look up a key and return possible completion for this key.List<Lookup.LookupResult>
lookup(CharSequence key, BooleanQuery contextFilerQuery, int num, boolean allTermsRequired, boolean doHighlight)
Look up a key and return possible completion for this key.boolean
store(OutputStream output)
abstract boolean
store(DataOutput output)
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
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Methods inherited from interface org.apache.lucene.util.Accountable
getChildResources, ramBytesUsed
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Field Detail
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CHARSEQUENCE_COMPARATOR
public static final Comparator<CharSequence> CHARSEQUENCE_COMPARATOR
A simple char-by-char comparator forCharSequence
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Method Detail
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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 - useSortedInputIterator
orUnsortedInputIterator
in such case.- Throws:
IOException
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load
public boolean load(InputStream input) throws IOException
- Throws:
IOException
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store
public boolean store(OutputStream output) throws IOException
- Throws:
IOException
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getCount
public abstract long getCount() throws IOException
Get the number of entries the lookup was built with- Returns:
- total number of suggester entries
- Throws:
IOException
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build
public abstract void build(InputIterator inputIterator) throws IOException
Builds up a new internalLookup
representation based on the givenInputIterator
. The implementation might re-sort the data internally.- Throws:
IOException
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lookup
public List<Lookup.LookupResult> lookup(CharSequence key, boolean onlyMorePopular, int num) throws IOException
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 resultsnum
- maximum number of results to return- Returns:
- a list of possible completions, with their relative weight (e.g. popularity)
- Throws:
IOException
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lookup
public abstract List<Lookup.LookupResult> lookup(CharSequence key, Set<BytesRef> contexts, boolean onlyMorePopular, int num) throws IOException
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.contexts
- contexts to filter the lookup by, or null if all contexts are allowed; if the suggestion contains any of the contexts, it's a matchonlyMorePopular
- return only more popular resultsnum
- maximum number of results to return- Returns:
- a list of possible completions, with their relative weight (e.g. popularity)
- Throws:
IOException
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lookup
public List<Lookup.LookupResult> lookup(CharSequence key, BooleanQuery contextFilerQuery, int num, boolean allTermsRequired, boolean doHighlight) throws IOException
Look up a key and return possible completion for this key. This needs to be overridden by all implementing classes as the default implementation just returns null- Parameters:
key
- the lookup keycontextFilerQuery
- A query for further filtering the result of the key lookupnum
- maximum number of results to returnallTermsRequired
- true is all terms are requireddoHighlight
- set to true if key should be highlighted- Returns:
- a list of suggestions/completions. The default implementation returns null, meaning each @Lookup implementation should override this and provide their own implementation
- Throws:
IOException
- when IO exception occurs
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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.
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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
- theDataInput
to load the lookup data.- Returns:
- true if completed successfully, false if unsuccessful or not supported.
- Throws:
IOException
- when fatal IO error occurs.
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