Package org.apache.tika.parser.html.charsetdetector

Class StandardHtmlEncodingDetector

java.lang.Object
org.apache.tika.parser.html.charsetdetector.StandardHtmlEncodingDetector
All Implemented Interfaces:
Serializable, EncodingDetector
public final class StandardHtmlEncodingDetector extends Object implements EncodingDetector
An encoding detector that tries to respect the spirit of the HTML spec part 12.2.3 "The input byte stream", or at least the part that is compatible with the implementation of tika.

https://html.spec.whatwg.org/multipage/parsing.html#the-input-byte-stream

If a resource was fetched over HTTP, then HTTP headers should be added to tika metadata when using detect(java.io.InputStream, org.apache.tika.metadata.Metadata), especially HttpHeaders.CONTENT_TYPE, as it may contain charset information.

This encoding detector may return null if no encoding is detected. It is meant to be used inside a CompositeEncodingDetector. For instance: 

 
     EncodingDetector detector = new CompositeEncodingDetector(
       Arrays.asList(
         new StandardHtmlEncodingDetector(),
         new Icu4jEncodingDetector()));

See Also:

  • Constructor Details

    • StandardHtmlEncodingDetector

      public StandardHtmlEncodingDetector()

  • Method Details

    • detect

      public Charset detect(InputStream input, Metadata metadata) throws IOException
      Description copied from interface: EncodingDetector
      Detects the character encoding of the given text document, or null if the encoding of the document can not be detected.

      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.

      Specified by:
      detect in interface EncodingDetector
      Parameters:
      input - text document input stream, or null
      metadata - input metadata for the document
      Returns:
      detected character encoding, or null
      Throws:
      IOException - if the document input stream could not be read

    • getMarkLimit

      public int getMarkLimit()

    • setMarkLimit

      @Field public void setMarkLimit(int markLimit)
      How far into the stream to read for charset detection. Default is 8192.