java.lang.Object
- org.apache.lucene.index.Terms

Direct Known Subclasses:

FieldReader, FilterLeafReader.FilterTerms, MultiTerms
```
public abstract class Terms
extends Object
```
Access to the terms in a specific field. See Fields.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields
Modifier and Type Field Description

static Terms[] EMPTY_ARRAY
Zero-length array of Terms.

Constructor Summary

Constructors
Modifier Constructor Description

protected Terms()
Sole constructor.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract int`	`getDocCount()`	Returns the number of documents that have at least one term for this field.
`BytesRef`	`getMax()`	Returns the largest term (in lexicographic order) in the field.
`BytesRef`	`getMin()`	Returns the smallest term (in lexicographic order) in the field.
`Object`	`getStats()`	Expert: returns additional information about this Terms instance for debugging purposes.
`abstract long`	`getSumDocFreq()`	Returns the sum of `TermsEnum.docFreq()` for all terms in this field.
`abstract long`	`getSumTotalTermFreq()`	Returns the sum of `TermsEnum.totalTermFreq()` for all terms in this field.
`static Terms`	`getTerms(LeafReader reader, String field)`	Returns the `Terms` index for this field, or `EMPTY` if it has none.
`abstract boolean`	`hasFreqs()`	Returns true if documents in this field store per-document term frequency (`PostingsEnum.freq()`).
`abstract boolean`	`hasOffsets()`	Returns true if documents in this field store offsets.
`abstract boolean`	`hasPayloads()`	Returns true if documents in this field store payloads.
`abstract boolean`	`hasPositions()`	Returns true if documents in this field store positions.
`TermsEnum`	`intersect(CompiledAutomaton compiled, BytesRef startTerm)`	Returns a TermsEnum that iterates over all terms and documents that are accepted by the provided `CompiledAutomaton`.
`abstract TermsEnum`	`iterator()`	Returns an iterator that will step through all terms.
`abstract long`	`size()`	Returns the number of terms for this field, or -1 if this measure isn't stored by the codec.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - EMPTY_ARRAY
```
public static final Terms[] EMPTY_ARRAY
```
    Zero-length array of Terms.
- Constructor Detail
  - Terms
```
protected Terms()
```
    Sole constructor. (For invocation by subclass constructors, typically implicit.)
- Method Detail
  - getTerms
```
public static Terms getTerms(LeafReader reader,
                             String field)
                      throws IOException
```
    Returns the Terms index for this field, or EMPTY if it has none.
    
    Returns:
    
    terms instance, or an empty instance if field does not exist in this reader
    
    Throws:
    
    IOException - if an I/O error occurs.
  - iterator
```
public abstract TermsEnum iterator()
                            throws IOException
```
    Returns an iterator that will step through all terms. This method will not return null.
    
    Throws:
    
    IOException
  - intersect
```
public TermsEnum intersect(CompiledAutomaton compiled,
                           BytesRef startTerm)
                    throws IOException
```
    Returns a TermsEnum that iterates over all terms and documents that are accepted by the provided CompiledAutomaton. If the startTerm is provided then the returned enum will only return terms > startTerm, but you still must call next() first to get to the first term. Note that the provided startTerm must be accepted by the automaton.
    This is an expert low-level API and will only work for NORMAL compiled automata. To handle any compiled automata you should instead use CompiledAutomaton.getTermsEnum(org.apache.lucene.index.Terms) instead.
    NOTE: the returned TermsEnum cannot seek.
    
    Throws:
    
    IOException
  - size
```
public abstract long size()
                   throws IOException
```
    Returns the number of terms for this field, or -1 if this measure isn't stored by the codec. Note that, just like other term measures, this measure does not take deleted documents into account.
    
    Throws:
    
    IOException
  - getSumTotalTermFreq
```
public abstract long getSumTotalTermFreq()
                                  throws IOException
```
    Returns the sum of TermsEnum.totalTermFreq() for all terms in this field. Note that, just like other term measures, this measure does not take deleted documents into account.
    
    Throws:
    
    IOException
  - getSumDocFreq
```
public abstract long getSumDocFreq()
                            throws IOException
```
    Returns the sum of TermsEnum.docFreq() for all terms in this field. Note that, just like other term measures, this measure does not take deleted documents into account.
    
    Throws:
    
    IOException
  - getDocCount
```
public abstract int getDocCount()
                         throws IOException
```
    Returns the number of documents that have at least one term for this field. Note that, just like other term measures, this measure does not take deleted documents into account.
    
    Throws:
    
    IOException
  - hasFreqs
```
public abstract boolean hasFreqs()
```
    Returns true if documents in this field store per-document term frequency (PostingsEnum.freq()).
  - hasOffsets
```
public abstract boolean hasOffsets()
```
    Returns true if documents in this field store offsets.
  - hasPositions
```
public abstract boolean hasPositions()
```
    Returns true if documents in this field store positions.
  - hasPayloads
```
public abstract boolean hasPayloads()
```
    Returns true if documents in this field store payloads.
  - getMin
```
public BytesRef getMin()
                throws IOException
```
    Returns the smallest term (in lexicographic order) in the field. Note that, just like other term measures, this measure does not take deleted documents into account. This returns null when there are no terms.
    
    Throws:
    
    IOException
  - getMax
```
public BytesRef getMax()
                throws IOException
```
    Returns the largest term (in lexicographic order) in the field. Note that, just like other term measures, this measure does not take deleted documents into account. This returns null when there are no terms.
    
    Throws:
    
    IOException
  - getStats
```
public Object getStats()
                throws IOException
```
    Expert: returns additional information about this Terms instance for debugging purposes.
    
    Throws:
    
    IOException

Class Terms

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

EMPTY_ARRAY

Constructor Detail

Terms

Method Detail

getTerms

iterator

intersect

size

getSumTotalTermFreq

getSumDocFreq

getDocCount

hasFreqs

hasOffsets

hasPositions

hasPayloads

getMin

getMax

getStats