Package org.apache.lucene.search.highlight

# Class TokenSources

java.lang.Object
org.apache.lucene.search.highlight.TokenSources

public class TokenSources extends Object
Convenience methods for obtaining a `TokenStream` for use with the `Highlighter` - can obtain from term vectors with offsets and positions or from an Analyzer re-parsing the stored content.

See Also:
  - `TokenStreamFromTermVector`

## Method Summary

Modifier and Type
Method
Description
`static TokenStream`
`getAnyTokenStream(IndexReader reader, int docId, String field, Analyzer analyzer)`
Deprecated.
`static TokenStream`
`getAnyTokenStream(IndexReader reader, int docId, String field, Document document, Analyzer analyzer)`
Deprecated.
`static TokenStream`
`getTermVectorTokenStreamOrNull(String field, Fields tvFields, int maxStartOffset)`
Get a token stream by un-inverting the term vector.
`static TokenStream`
`getTokenStream(String field, String contents, Analyzer analyzer)`
Deprecated.
`static TokenStream`
`getTokenStream(String field, Fields tvFields, String text, Analyzer analyzer, int maxStartOffset)`
Get a token stream from either un-inverting a term vector if possible, or by analyzing the text.
`static TokenStream`
`getTokenStream(Document doc, String field, Analyzer analyzer)`
Deprecated.
`static TokenStream`
`getTokenStream(IndexReader reader, int docId, String field, Analyzer analyzer)`
Deprecated.
`static TokenStream`
`getTokenStream(Terms tpv)`
Deprecated.
`static TokenStream`
`getTokenStream(Terms vector, boolean tokenPositionsGuaranteedContiguous)`
Deprecated.
`static TokenStream`
`getTokenStreamWithOffsets(IndexReader reader, int docId, String field)`
Deprecated.

### Methods inherited from class java.lang.Object

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

## Method Details

### getTokenStream

public static TokenStream getTokenStream(String field, Fields tvFields, String text, Analyzer analyzer, int maxStartOffset) throws IOException
Get a token stream from either un-inverting a term vector if possible, or by analyzing the text.

WARNING: Don't call this if there is more than one value for this field. If there are, and if there are term vectors, then there is a single tokenstream with offsets suggesting all the field values were concatenated.

Parameters:
  `field` - The field to either get term vectors from or to analyze the text from.
  `tvFields` - from `TermVectors.get(int)`. Possibly null. For performance, this instance should be re-used for the same document (e.g. when highlighting multiple fields).
  `text` - the text to analyze, failing term vector un-inversion
  `analyzer` - the analyzer to analyze `text` with, failing term vector un-inversion
  `maxStartOffset` - Terms with a startOffset greater than this aren't returned. Use -1 for no limit. Suggest using `Highlighter.getMaxDocCharsToAnalyze()` - 1.
Returns:
  a token stream from either term vectors, or from analyzing the text. Never null.
Throws:
  `IOException`

### getTermVectorTokenStreamOrNull

public static TokenStream getTermVectorTokenStreamOrNull(String field, Fields tvFields, int maxStartOffset) throws IOException
Get a token stream by un-inverting the term vector. This method returns null if `tvFields` is null or if the field has no term vector, or if the term vector doesn't have offsets. Positions are recommended on the term vector but it isn't strictly required.

Parameters:
  `field` - The field to get term vectors from.
  `tvFields` - from `TermVectors.get(int)`. Possibly null. For performance, this instance should be re-used for the same document (e.g. when highlighting multiple fields).
  `maxStartOffset` - Terms with a startOffset greater than this aren't returned. Use -1 for no limit. Suggest using `Highlighter.getMaxDocCharsToAnalyze()` - 1
Returns:
  a token stream from term vectors. Null if no term vectors with the right options.
Throws:
  `IOException`

### getAnyTokenStream

@Deprecated public static TokenStream getAnyTokenStream(IndexReader reader, int docId, String field, Document document, Analyzer analyzer) throws IOException
Deprecated.
A convenience method that tries to first get a `TokenStreamFromTermVector` for the specified docId, then, falls back to using the passed in `Document` to retrieve the TokenStream. This is useful when you already have the document, but would prefer to use the vector first.

Parameters:
  `reader` - The `IndexReader` to use to try and get the vector from
  `docId` - The docId to retrieve.
  `field` - The field to retrieve on the document
  `document` - The document to fall back on
  `analyzer` - The analyzer to use for creating the TokenStream if the vector doesn't exist
Returns:
  The `TokenStream` for the `IndexableField` on the `Document`
Throws:
  `IOException` - if there was an error loading

### getAnyTokenStream

@Deprecated public static TokenStream getAnyTokenStream(IndexReader reader, int docId, String field, Analyzer analyzer) throws IOException
Deprecated.
A convenience method that tries a number of approaches to getting a token stream. The cost of finding there are no termVectors in the index is minimal (1000 invocations still registers 0 ms). So this "lazy" (flexible?) approach to coding is probably acceptable

Returns:
  null if field not stored correctly
Throws:
  `IOException` - If there is a low-level I/O error

### getTokenStream

@Deprecated public static TokenStream getTokenStream(Terms vector, boolean tokenPositionsGuaranteedContiguous) throws IOException
Deprecated.
Simply calls `getTokenStream(org.apache.lucene.index.Terms)` now.

Throws:
  `IOException`

### getTokenStream

@Deprecated public static TokenStream getTokenStream(Terms tpv) throws IOException
Deprecated.
Returns a token stream generated from a `Terms`. This can be used to feed the highlighter with a pre-parsed token stream. The `Terms` must have offsets available. If there are no positions available, all tokens will have position increments reflecting adjacent tokens, or coincident when terms share a start offset. If there are stopwords filtered from the index, you probably want to ensure term vectors have positions so that phrase queries won't match across stopwords.

Throws:
  `IllegalArgumentException` - if no offsets are available
  `IOException`

### getTokenStreamWithOffsets

@Deprecated public static TokenStream getTokenStreamWithOffsets(IndexReader reader, int docId, String field) throws IOException
Deprecated.
Returns a `TokenStream` with positions and offsets constructed from field termvectors. If the field has no termvectors or offsets are not included in the termvector, return null. See `getTokenStream(org.apache.lucene.index.Terms)` for an explanation of what happens when positions aren't present.

Parameters:
  `reader` - the `IndexReader` to retrieve term vectors from
  `docId` - the document to retrieve termvectors for
  `field` - the field to retrieve termvectors for
Returns:
  a `TokenStream`, or null if offsets are not available
Throws:
  `IOException` - If there is a low-level I/O error
See Also:
  - `getTokenStream(org.apache.lucene.index.Terms)`

### getTokenStream

@Deprecated public static TokenStream getTokenStream(IndexReader reader, int docId, String field, Analyzer analyzer) throws IOException
Deprecated.

Throws:
  `IOException`

### getTokenStream

@Deprecated public static TokenStream getTokenStream(Document doc, String field, Analyzer analyzer)
Deprecated.

### getTokenStream

@Deprecated public static TokenStream getTokenStream(String field, String contents, Analyzer analyzer)
Deprecated.