org.apache.tika.parser.txt
Class CharsetMatch

java.lang.Object
  extended by org.apache.tika.parser.txt.CharsetMatch
All Implemented Interfaces:
java.lang.Comparable<CharsetMatch>

public class CharsetMatch
extends java.lang.Object
implements java.lang.Comparable<CharsetMatch>

This class represents a charset that has been identified by a CharsetDetector as a possible encoding for a set of input data. From an instance of this class, you can ask for a confidence level in the charset identification, or for Java Reader or String to access the original byte data in Unicode form.

Instances of this class are created only by CharsetDetectors.

Note: this class has a natural ordering that is inconsistent with equals. The natural ordering is based on the match confidence value.


Field Summary
static int BOM
          Bit flag indicating the match is based on the presence of a BOM.
static int DECLARED_ENCODING
          Bit flag indicating he match is based on the declared encoding.
static int ENCODING_SCHEME
          Bit flag indicating the match is based on the the encoding scheme.
static int LANG_STATISTICS
          Bit flag indicating the match is based on language statistics.
 
Method Summary
 int compareTo(CharsetMatch other)
          Compare to other CharsetMatch objects.
 int getConfidence()
          Get an indication of the confidence in the charset detected.
 java.lang.String getLanguage()
          Get the ISO code for the language of the detected charset.
 int getMatchType()
          Return flags indicating what it was about the input data that caused this charset to be considered as a possible match.
 java.lang.String getName()
          Get the name of the detected charset.
 java.io.Reader getReader()
          Create a java.io.Reader for reading the Unicode character data corresponding to the original byte data supplied to the Charset detect operation.
 java.lang.String getString()
          Create a Java String from Unicode character data corresponding to the original byte data supplied to the Charset detect operation.
 java.lang.String getString(int maxLength)
          Create a Java String from Unicode character data corresponding to the original byte data supplied to the Charset detect operation.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

ENCODING_SCHEME

public static final int ENCODING_SCHEME
Bit flag indicating the match is based on the the encoding scheme.

See Also:
getMatchType(), Constant Field Values

BOM

public static final int BOM
Bit flag indicating the match is based on the presence of a BOM.

See Also:
getMatchType(), Constant Field Values

DECLARED_ENCODING

public static final int DECLARED_ENCODING
Bit flag indicating he match is based on the declared encoding.

See Also:
getMatchType(), Constant Field Values

LANG_STATISTICS

public static final int LANG_STATISTICS
Bit flag indicating the match is based on language statistics.

See Also:
getMatchType(), Constant Field Values
Method Detail

getReader

public java.io.Reader getReader()
Create a java.io.Reader for reading the Unicode character data corresponding to the original byte data supplied to the Charset detect operation.

CAUTION: if the source of the byte data was an InputStream, a Reader can be created for only one matching char set using this method. If more than one charset needs to be tried, the caller will need to reset the InputStream and create InputStreamReaders itself, based on the charset name.

Returns:
the Reader for the Unicode character data.

getString

public java.lang.String getString()
                           throws java.io.IOException
Create a Java String from Unicode character data corresponding to the original byte data supplied to the Charset detect operation.

Returns:
a String created from the converted input data.
Throws:
java.io.IOException

getString

public java.lang.String getString(int maxLength)
                           throws java.io.IOException
Create a Java String from Unicode character data corresponding to the original byte data supplied to the Charset detect operation. The length of the returned string is limited to the specified size; the string will be trunctated to this length if necessary. A limit value of zero or less is ignored, and treated as no limit.

Parameters:
maxLength - The maximium length of the String to be created when the source of the data is an input stream, or -1 for unlimited length.
Returns:
a String created from the converted input data.
Throws:
java.io.IOException

getConfidence

public int getConfidence()
Get an indication of the confidence in the charset detected. Confidence values range from 0-100, with larger numbers indicating a better match of the input data to the characteristics of the charset.

Returns:
the confidence in the charset match

getMatchType

public int getMatchType()
Return flags indicating what it was about the input data that caused this charset to be considered as a possible match. The result is a bitfield containing zero or more of the flags ENCODING_SCHEME, BOM, DECLARED_ENCODING, and LANG_STATISTICS. A result of zero means no information is available.

Note: currently, this method always returns zero.

Returns:
the type of match found for this charset.

getName

public java.lang.String getName()
Get the name of the detected charset. The name will be one that can be used with other APIs on the platform that accept charset names. It is the "Canonical name" as defined by the class java.nio.charset.Charset; for charsets that are registered with the IANA charset registry, this is the MIME-preferred registerd name.

Returns:
The name of the charset.
See Also:
Charset, InputStreamReader

getLanguage

public java.lang.String getLanguage()
Get the ISO code for the language of the detected charset.

Returns:
The ISO code for the language or null if the language cannot be determined.

compareTo

public int compareTo(CharsetMatch other)
Compare to other CharsetMatch objects. Comparison is based on the match confidence value, which allows CharsetDetector.detectAll() to order its results.

Specified by:
compareTo in interface java.lang.Comparable<CharsetMatch>
Parameters:
o - the CharsetMatch object to compare against.
Returns:
a negative integer, zero, or a positive integer as the confidence level of this CharsetMatch is less than, equal to, or greater than that of the argument.
Throws:
java.lang.ClassCastException - if the argument is not a CharsetMatch.


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