Package net.sf.basedb.util.charset

Class CharsetDetector

java.lang.Object

net.sf.basedb.util.charset.CharsetDetector

public class CharsetDetector
extends Object

Utility class for testing if a text stream can be parsed using a given character set. There are two sides of the testing: The technical side which checks for invalid byte sequences, etc. This works well for UTF-8 but it is, for example, not able to discriminate betwee different ISO-8859-? or Windows-? encoding. The content side which can check that the parsed content contains some expected text strings. This can be used to discriminate between diffent ISO-8859-? or Windows-? encoding by using careful choices of text strings to look for.

Since:

3.15

Author:

nicklas

Field Summary

Fields

Modifier and Type	Field	Description
private final Charset	charset
private final StringDetector	lineTester
private long	parsedBytes
private int	parsedLines
private IOException	parsingFailure

Constructor Summary

Constructors

Constructor	Description
CharsetDetector(Charset charset)	Create a detector for the given character set that only detects technical issues.
CharsetDetector(Charset charset, StringDetector lineTester)	Create a detector for the given character set that uses technical an content-based detection.

Method Summary

Modifier and Type	Method	Description
Charset	getCharset()	Get the character set this detector is configured to use.
long	getParsedBytes()	Get the number of bytes that the last test operation parsed.
int	getParsedLines()
IOException	getParsingFailure()	If the last test failed, get the exception that was thrown by the parser.
boolean	testIt(InputStream in)	Test if the given input stream can be parsed with the configured character set.
boolean	testIt(InputStream in, long maxBytes, int maxLines)	Test if the given input stream can be parsed with the configured character set.

Methods inherited from class java.lang.Object

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

Field Details

charset

private final Charset charset

lineTester

private final StringDetector lineTester

parsingFailure

private IOException parsingFailure

parsedBytes

private long parsedBytes

parsedLines

private int parsedLines

Constructor Details

CharsetDetector

public CharsetDetector(Charset charset)

Create a detector for the given character set that only detects technical issues. Useful for UTF-8.

CharsetDetector

public CharsetDetector(Charset charset,
 StringDetector lineTester)

Create a detector for the given character set that uses technical an content-based detection. If no lineTester is given it will use only technical detection.

Method Details

getCharset

public Charset getCharset()

Get the character set this detector is configured to use.

testIt

public boolean testIt(InputStream in)

Test if the given input stream can be parsed with the configured character set. The stream is read until the end is reached or until there is a decoding failure.

testIt

public boolean testIt(InputStream in,
 long maxBytes,
 int maxLines)

Test if the given input stream can be parsed with the configured character set. The stream is read until maxBytes bytes has been parsed or until there is a decoding failure.

Parameters:

maxBytes - Max number of bytes to parse or -1 to not use a limit

maxLines - Max number of lines to parse or -1 to not use a limit

getParsedBytes

public long getParsedBytes()

Get the number of bytes that the last test operation parsed.

getParsedLines

public int getParsedLines()

getParsingFailure

public IOException getParsingFailure()

If the last test failed, get the exception that was thrown by the parser.