com.fasterxml.jackson.core.format

Class DataFormatDetector

java.lang.Object

com.fasterxml.jackson.core.format.DataFormatDetector

public class DataFormatDetector
extends Object

Simple helper class that allows data format (content type) auto-detection, given an ordered set of JsonFactory instances to use for actual low-level detection.

Field Summary

Fields

Modifier and Type	Field and Description
protected JsonFactory[]	_detectors Ordered list of factories which both represent data formats to detect (in precedence order, starting with highest) and are used for actual detection.
protected int	_maxInputLookahead Maximum number of leading bytes of the input that we can read to determine data format.
protected MatchStrength	_minimalMatch Strength of minimal match we accept as the answer, unless better matches are found.
protected MatchStrength	_optimalMatch Strength of match we consider to be good enough to be used without checking any other formats.
static int	DEFAULT_MAX_INPUT_LOOKAHEAD By default we will look ahead at most 64 bytes; in most cases, much less (4 bytes or so) is needed, but we will allow bit more leniency to support data formats that need more complex heuristics.

Constructor Summary

Constructors

Constructor and Description
DataFormatDetector(Collection<JsonFactory> detectors)
DataFormatDetector(JsonFactory... detectors)

Method Summary

Methods

Modifier and Type	Method and Description
DataFormatMatcher	findFormat(byte[] fullInputData) Method to call to find format that given content (full document) has, as per configuration of this detector instance.
DataFormatMatcher	findFormat(byte[] fullInputData, int offset, int len) Method to call to find format that given content (full document) has, as per configuration of this detector instance.
DataFormatMatcher	findFormat(InputStream in) Method to call to find format that content (accessible via given InputStream) given has, as per configuration of this detector instance.
String	toString()
DataFormatDetector	withMaxInputLookahead(int lookaheadBytes) Method that will return a detector instance that allows detectors to read up to specified number of bytes when determining format match strength.
DataFormatDetector	withMinimalMatch(MatchStrength minMatch) Method that will return a detector instance that uses given minimal match level; match that may be returned unless a stronger match is found with other format detectors.
DataFormatDetector	withOptimalMatch(MatchStrength optMatch) Method that will return a detector instance that uses given optimal match level (match that is considered sufficient to return, without trying to find stronger matches with other formats).

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_MAX_INPUT_LOOKAHEAD

public static final int DEFAULT_MAX_INPUT_LOOKAHEAD

By default we will look ahead at most 64 bytes; in most cases, much less (4 bytes or so) is needed, but we will allow bit more leniency to support data formats that need more complex heuristics.

See Also:

Constant Field Values

_detectors

protected final JsonFactory[] _detectors

Ordered list of factories which both represent data formats to detect (in precedence order, starting with highest) and are used for actual detection.

_optimalMatch

protected final MatchStrength _optimalMatch

Strength of match we consider to be good enough to be used without checking any other formats. Default value is MatchStrength.SOLID_MATCH,

_minimalMatch

protected final MatchStrength _minimalMatch

Strength of minimal match we accept as the answer, unless better matches are found. Default value is MatchStrength.WEAK_MATCH,

_maxInputLookahead

protected final int _maxInputLookahead

Maximum number of leading bytes of the input that we can read to determine data format.

Default value is DEFAULT_MAX_INPUT_LOOKAHEAD.

Constructor Detail

DataFormatDetector

public DataFormatDetector(JsonFactory... detectors)

DataFormatDetector

public DataFormatDetector(Collection<JsonFactory> detectors)

Method Detail

withOptimalMatch

public DataFormatDetector withOptimalMatch(MatchStrength optMatch)

Method that will return a detector instance that uses given optimal match level (match that is considered sufficient to return, without trying to find stronger matches with other formats).

withMinimalMatch

public DataFormatDetector withMinimalMatch(MatchStrength minMatch)

Method that will return a detector instance that uses given minimal match level; match that may be returned unless a stronger match is found with other format detectors.

withMaxInputLookahead

public DataFormatDetector withMaxInputLookahead(int lookaheadBytes)

Method that will return a detector instance that allows detectors to read up to specified number of bytes when determining format match strength.

findFormat

public DataFormatMatcher findFormat(InputStream in)
                             throws IOException

Method to call to find format that content (accessible via given InputStream) given has, as per configuration of this detector instance.

Returns:

Matcher object which contains result; never null, even in cases where no match (with specified minimal match strength) is found.

Throws:

IOException

findFormat

public DataFormatMatcher findFormat(byte[] fullInputData)
                             throws IOException

Method to call to find format that given content (full document) has, as per configuration of this detector instance.

Returns:

Matcher object which contains result; never null, even in cases where no match (with specified minimal match strength) is found.

Throws:

IOException

findFormat

public DataFormatMatcher findFormat(byte[] fullInputData,
                           int offset,
                           int len)
                             throws IOException

Method to call to find format that given content (full document) has, as per configuration of this detector instance.

Returns:

Matcher object which contains result; never null, even in cases where no match (with specified minimal match strength) is found.

Throws:

IOException

Since:

2.1

toString

public String toString()

Overrides:

toString in class Object