Package com.fasterxml.jackson.core.json

Class ByteSourceJsonBootstrapper

java.lang.Object

com.fasterxml.jackson.core.json.ByteSourceJsonBootstrapper

public final class ByteSourceJsonBootstrapper
extends Object

This class is used to determine the encoding of byte stream that is to contain JSON content. Rules are fairly simple, and defined in JSON specification (RFC-4627 or newer), except for BOM handling, which is a property of underlying streams.

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	_bigEndian	Whether input has been detected to be in Big-Endian encoding or not.
private final boolean	_bufferRecyclable	Flag that indicates whether buffer above is to be recycled after being used or not.
private int	_bytesPerChar
private final IOContext	_context
private final InputStream	_in
private final byte[]	_inputBuffer
private int	_inputEnd
private int	_inputPtr
private static final int	STRING_READER_BYTE_ARRAY_LENGTH_LIMIT
static final byte	UTF8_BOM_1
static final byte	UTF8_BOM_2
static final byte	UTF8_BOM_3

Constructor Summary

Constructors

Constructor	Description
ByteSourceJsonBootstrapper(IOContext ctxt, byte[] inputBuffer, int inputStart, int inputLen)
ByteSourceJsonBootstrapper(IOContext ctxt, InputStream in)

Method Summary

Modifier and Type	Method	Description
private boolean	checkUTF16(int i16)
private boolean	checkUTF32(int quad)
JsonParser	constructParser(int parserFeatures, ObjectCodec codec, ByteQuadsCanonicalizer rootByteSymbols, CharsToNameCanonicalizer rootCharSymbols, int factoryFeatures)
Reader	constructReader()
JsonEncoding	detectEncoding()	Method that should be called after constructing an instace.
protected boolean	ensureLoaded(int minimum)
private boolean	handleBOM(int quad)
static MatchStrength	hasJSONFormat(InputAccessor acc)	Current implementation is not as thorough as other functionality (ByteSourceJsonBootstrapper); supports UTF-8, for example.
private void	reportWeirdUCS4(String type)
private static int	skipSpace(InputAccessor acc)
private static int	skipSpace(InputAccessor acc, byte b)
static int	skipUTF8BOM(DataInput input)	Helper method that may be called to see if given DataInput has BOM marker, and if so, to skip it.
private static MatchStrength	tryMatch(InputAccessor acc, String matchStr, MatchStrength fullMatchStrength)

Methods inherited from class java.lang.Object

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

Field Details

UTF8_BOM_1

public static final byte UTF8_BOM_1

See Also:

• Constant Field Values

UTF8_BOM_2

public static final byte UTF8_BOM_2

See Also:

• Constant Field Values

UTF8_BOM_3

public static final byte UTF8_BOM_3

See Also:

• Constant Field Values

STRING_READER_BYTE_ARRAY_LENGTH_LIMIT

private static final int STRING_READER_BYTE_ARRAY_LENGTH_LIMIT

See Also:

• Constant Field Values

_context

private final IOContext _context

_in

private final InputStream _in

_inputBuffer

private final byte[] _inputBuffer

_inputPtr

private int _inputPtr

_inputEnd

private int _inputEnd

_bufferRecyclable

private final boolean _bufferRecyclable

Flag that indicates whether buffer above is to be recycled after being used or not.

_bigEndian

private boolean _bigEndian

Whether input has been detected to be in Big-Endian encoding or not.

_bytesPerChar

private int _bytesPerChar

Constructor Details

ByteSourceJsonBootstrapper

public ByteSourceJsonBootstrapper(IOContext ctxt,
 InputStream in)

ByteSourceJsonBootstrapper

public ByteSourceJsonBootstrapper(IOContext ctxt,
 byte[] inputBuffer,
 int inputStart,
 int inputLen)

Method Details

detectEncoding

public JsonEncoding detectEncoding()
                            throws IOException

Method that should be called after constructing an instace. It will figure out encoding that content uses, to allow for instantiating a proper scanner object.

Returns:

JsonEncoding detected, if any; JsonEncoding.UTF8 otherwise

Throws:

IOException - If read from underlying input source fails

skipUTF8BOM

public static int skipUTF8BOM(DataInput input)
                       throws IOException

Helper method that may be called to see if given DataInput has BOM marker, and if so, to skip it.

Parameters:

input - DataInput to read content from

Returns:

Byte (as unsigned int) read after possible UTF-8 BOM

Throws:

IOException - If read from underlying input source fails

Since:

2.8

constructReader

public Reader constructReader()
                       throws IOException

Throws:

IOException

constructParser

public JsonParser constructParser(int parserFeatures,
 ObjectCodec codec,
 ByteQuadsCanonicalizer rootByteSymbols,
 CharsToNameCanonicalizer rootCharSymbols,
 int factoryFeatures)
                           throws IOException

Throws:

IOException

hasJSONFormat

public static MatchStrength hasJSONFormat(InputAccessor acc)
                                   throws IOException

Current implementation is not as thorough as other functionality (ByteSourceJsonBootstrapper); supports UTF-8, for example. But it should work, for now, and can be improved as necessary.

Parameters:

acc - InputAccessor to use for accessing content to check

Returns:

Strength of match (never null)

Throws:

IOException - if input access fails due to read problem

tryMatch

private static MatchStrength tryMatch(InputAccessor acc,
 String matchStr,
 MatchStrength fullMatchStrength)
                               throws IOException

Throws:

IOException

skipSpace

private static int skipSpace(InputAccessor acc)
                      throws IOException

Throws:

IOException

skipSpace

private static int skipSpace(InputAccessor acc,
 byte b)
                      throws IOException

Throws:

IOException

handleBOM

private boolean handleBOM(int quad)
                   throws IOException

Returns:

True if a BOM was succesfully found, and encoding thereby recognized.

Throws:

IOException

checkUTF32

private boolean checkUTF32(int quad)
                    throws IOException

Throws:

IOException

checkUTF16

private boolean checkUTF16(int i16)

reportWeirdUCS4

private void reportWeirdUCS4(String type)
                      throws IOException

Throws:

IOException

ensureLoaded

protected boolean ensureLoaded(int minimum)
                        throws IOException

Throws:

IOException