Package org.apache.tika.detect

Interface EncodingDetector

All Superinterfaces:

SelfConfiguring, Serializable

All Known Subinterfaces:

MetaEncodingDetector

All Known Implementing Classes:

BOMDetector, CompositeEncodingDetector, DefaultEncodingDetector, HtmlEncodingDetector, Icu4jEncodingDetector, JunkFilterEncodingDetector, MetadataCharsetDetector, MojibusterEncodingDetector, NaiveBayesBigramEncodingDetector, OverrideEncodingDetector, StandardHtmlEncodingDetector, UniversalEncodingDetector, Utf16SpecialistEncodingDetector

public interface EncodingDetector
extends Serializable, SelfConfiguring

Character encoding detector. Implementations use various heuristics to detect the character encoding of a text document based on given input metadata or the first few bytes of the document stream.

Detectors return a ranked list of EncodingResults in descending confidence order. An empty list means no opinion. Results carry a EncodingResult.ResultType indicating the nature of the evidence: DECLARATIVE (BOM, HTML meta charset), STRUCTURAL (byte-grammar proof), or STATISTICAL (probabilistic model). A MetaEncodingDetector uses these types to arbitrate when detectors disagree.

Since:

Apache Tika 0.4

Method Summary

Modifier and Type	Method	Description
List<EncodingResult>	detect(TikaInputStream tis, Metadata metadata, ParseContext parseContext)	Detects the character encoding of the given text document.

Method Details

detect

List<EncodingResult> detect(TikaInputStream tis,
 Metadata metadata,
 ParseContext parseContext)
                     throws IOException

Detects the character encoding of the given text document.

Returns an empty list if the encoding cannot be determined. Returns a ranked list of candidates in descending confidence order otherwise. The first entry is always the best guess.

If the document input stream is not available, then the first argument may be null. Otherwise the detector may read bytes from the start of the stream to help in encoding detection. The given stream is guaranteed to support the mark feature and the detector is expected to mark the stream before reading any bytes from it, and to reset the stream before returning. The stream must not be closed by the detector.

The given input metadata is only read, not modified, by the detector.

Parameters:

tis - text document input stream, or null

metadata - input metadata for the document

parseContext - the parse context

Returns:

ranked list of encoding results, empty if unknown; never null

Throws:

IOException - if the document input stream could not be read