Class UTF32Reader

java.lang.Object

java.io.Reader

tools.jackson.core.io.UTF32Reader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

public class UTF32Reader
extends Reader

Since JDK does not come with UTF-32/UCS-4, let's implement a simple decoder to use.

Field Summary

Fields

Modifier and Type	Field	Description
private final boolean	_autoClose	Whether underlying InputStream (if any) should be closed when this Reader is closed or not.
protected final boolean	_bigEndian
protected byte[]	_buffer
protected int	_byteCount	Total read byte count; used for error reporting purposes
protected int	_charCount	Total read character count; used for error reporting purposes
protected final IOContext	_context
protected InputStream	_in
protected int	_length
protected final boolean	_managedBuffers
protected int	_ptr
protected char	_surrogate	Although input is fine with full Unicode set, Java still uses 16-bit chars, so we may have to split high-order chars into surrogate pairs.
protected char[]	_tmpBuf
protected static final int	LAST_VALID_UNICODE_CHAR	JSON actually limits available Unicode range in the high end to the same as xml (to basically limit UTF-8 max byte sequence length to 4)
protected static final char	NC

Fields inherited from class Reader

lock

Constructor Summary

Constructors

Constructor	Description
UTF32Reader(IOContext ctxt, InputStream in, boolean autoClose, byte[] buf, int ptr, int len, boolean isBigEndian)

Method Summary

Modifier and Type	Method	Description
void	close()
private void	freeBuffers()	This method should be called along with (or instead of) normal close.
private boolean	loadMore(int available)
int	read()	Although this method is implemented by the base class, AND it should never be called by main code, let's still implement it bit more efficiently just in case
int	read(char[] cbuf, int start, int len)
private void	reportBounds(char[] cbuf, int start, int len)
private void	reportInvalid(int value, int offset, String msg)
private void	reportStrangeStream()
private void	reportUnexpectedEOF(int gotBytes, int needed)

Methods inherited from class Reader

mark, markSupported, nullReader, of, read, read, readAllAsString, readAllLines, ready, reset, skip, transferTo

Methods inherited from class Object

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

Field Details

LAST_VALID_UNICODE_CHAR

protected static final int LAST_VALID_UNICODE_CHAR

JSON actually limits available Unicode range in the high end to the same as xml (to basically limit UTF-8 max byte sequence length to 4)

See Also:

• Constant Field Values

NC

protected static final char NC

See Also:

• Constant Field Values

_context

protected final IOContext _context

_in

protected InputStream _in

_autoClose

private final boolean _autoClose

Whether underlying InputStream (if any) should be closed when this Reader is closed or not.

_buffer

protected byte[] _buffer

_ptr

protected int _ptr

_length

protected int _length

_bigEndian

protected final boolean _bigEndian

_surrogate

protected char _surrogate

Although input is fine with full Unicode set, Java still uses 16-bit chars, so we may have to split high-order chars into surrogate pairs.

_charCount

protected int _charCount

Total read character count; used for error reporting purposes

_byteCount

protected int _byteCount

Total read byte count; used for error reporting purposes

_managedBuffers

protected final boolean _managedBuffers

_tmpBuf

protected char[] _tmpBuf

Constructor Details

UTF32Reader

public UTF32Reader(IOContext ctxt,
 InputStream in,
 boolean autoClose,
 byte[] buf,
 int ptr,
 int len,
 boolean isBigEndian)

Method Details

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class Reader

Throws:

IOException

read

public int read()
         throws IOException

Although this method is implemented by the base class, AND it should never be called by main code, let's still implement it bit more efficiently just in case

Overrides:

read in class Reader

Throws:

IOException

read

public int read(char[] cbuf,
 int start,
 int len)
         throws IOException

Specified by:

read in class Reader

Throws:

IOException

reportUnexpectedEOF

private void reportUnexpectedEOF(int gotBytes,
 int needed)
                          throws IOException

Throws:

IOException

reportInvalid

private void reportInvalid(int value,
 int offset,
 String msg)
                    throws IOException

Throws:

IOException

loadMore

private boolean loadMore(int available)
                  throws IOException

Parameters:

available - Number of "unused" bytes in the input buffer

Returns:

True, if enough bytes were read to allow decoding of at least one full character; false if EOF was encountered instead.

Throws:

IOException

freeBuffers

private void freeBuffers()

This method should be called along with (or instead of) normal close. After calling this method, no further reads should be tried. Method will try to recycle read buffers (if any).

reportBounds

private void reportBounds(char[] cbuf,
 int start,
 int len)
                   throws IOException

Throws:

IOException

reportStrangeStream

private void reportStrangeStream()
                          throws IOException

Throws:

IOException