Top Description Fields Constructors Methods
org.hsqldb.lib

public Class HsqlByteArrayInputStream

extends InputStream
implements DataInput
Class Inheritance
All Implemented Interfaces
java.io.DataInput
Known Direct Subclasses
org.hsqldb.rowio.RowInputBase
Imports
java.io.DataInput, .EOFException, .IOException, .InputStream

This class is a replacement for both java.io.ByteArrayInputStream (without synchronization) and java.io.DataInputStream
Author
Fred Toussi (fredt@users dot sourceforge.net)
Since
1.7.2
Version
2.4.0

Field Summary

Modifier and TypeField and Description
protected byte[]
protected int
protected int
protected int

Constructor Summary

AccessConstructor and Description
public
public
HsqlByteArrayInputStream(byte[] buf, int offset, int length)

Method Summary

Modifier and TypeMethod and Description
public int
available()

Overrides java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.

public void
close()

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Closes this input stream and releases any system resources associated with the stream.

public final long
public void
mark(int readAheadLimit)

Overrides java.io.InputStream.mark.

Marks the current position in this input stream.

public boolean
markSupported()

Overrides java.io.InputStream.markSupported.

Tests if this input stream supports the mark and reset methods.

public int
read()

Implements abstract java.io.InputStream.read.

Reads the next byte of data from the input stream.

public int
read(byte[] b, int off, int len)

Overrides java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes.

public boolean
readBoolean()

Implements java.io.DataInput.readBoolean.

Reads one input byte and returns true if that byte is nonzero, false if that byte is zero.

public byte
readByte()

Implements java.io.DataInput.readByte.

Reads and returns one input byte.

public char
readChar()

Implements java.io.DataInput.readChar.

Reads two input bytes and returns a char value.

public final double
readDouble()

Implements java.io.DataInput.readDouble.

Reads eight input bytes and returns a double value.

public final float
readFloat()

Implements java.io.DataInput.readFloat.

Reads four input bytes and returns a float value.

public void
readFully(byte[] b)

Implements java.io.DataInput.readFully.

Reads some bytes from an input stream and stores them into the buffer array b.

public final void
readFully(byte[] b, int off, int len)

Implements java.io.DataInput.readFully.

Reads len bytes from an input stream.

public int
readInt()

Implements java.io.DataInput.readInt.

Reads four input bytes and returns an int value.

public String
readLine()

Implements java.io.DataInput.readLine.

Reads the next line of text from the input stream.

public long
readLong()

Implements java.io.DataInput.readLong.

Reads eight input bytes and returns a long value.

public short
readShort()

Implements java.io.DataInput.readShort.

Reads two input bytes and returns a short value.

public final int
readUnsignedByte()

Implements java.io.DataInput.readUnsignedByte.

Reads one input byte, zero-extends it to type int, and returns the result, which is therefore in the range 0 through 255.

public final int
readUnsignedShort()

Implements java.io.DataInput.readUnsignedShort.

Reads two input bytes and returns an int value in the range 0 through 65535.

public String
readUTF()

Implements java.io.DataInput.readUTF.

Reads in a string that has been encoded using a modified UTF-8 format.

public void
reset()

Overrides java.io.InputStream.reset.

Repositions this stream to the position at the time the mark method was last called on this input stream.

public long
skip(long n)

Overrides java.io.InputStream.skip.

Skips over and discards n bytes of data from this input stream.

public int
skipBytes(int n)

Implements java.io.DataInput.skipBytes.

Makes an attempt to skip over n bytes of data from the input stream, discarding the skipped bytes.

Inherited from java.io.InputStream:
nullInputStreamreadreadAllBytesreadNBytesreadNBytesskipNBytestransferTo

Field Detail

bufferback to summary
protected byte[] buffer
countback to summary
protected int count
markback to summary
protected int mark
posback to summary
protected int pos

Constructor Detail

HsqlByteArrayInputStreamback to summary
public HsqlByteArrayInputStream(byte[] buf)
HsqlByteArrayInputStreamback to summary
public HsqlByteArrayInputStream(byte[] buf, int offset, int length)

Method Detail

availableback to summary
public int available()

Overrides java.io.InputStream.available.

Doc from java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected. The read might be on the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

Note that while some implementations of InputStream will return the total number of bytes in the stream, many will not. It is never correct to use the return value of this method to allocate a buffer intended to hold all data in this stream.

A subclass's implementation of this method may choose to throw an IOException if this input stream has been closed by invoking the close() method.

closeback to summary
public void close()

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Doc from java.io.InputStream.close.

Closes this input stream and releases any system resources associated with the stream.

getPosback to summary
public final long getPos()
markback to summary
public void mark(int readAheadLimit)

Overrides java.io.InputStream.mark.

Doc from java.io.InputStream.mark.

Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called.

Marking a closed stream should not have any effect on the stream.

markSupportedback to summary
public boolean markSupported()

Overrides java.io.InputStream.markSupported.

Doc from java.io.InputStream.markSupported.

Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance.

readback to summary
public int read()

Implements abstract java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

readback to summary
public int read(byte[] b, int off, int len)

Overrides java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off-1] and elements b[off+len] through b[b.length-1] are unaffected.

readBooleanback to summary
public boolean readBoolean() throws IOException

Implements java.io.DataInput.readBoolean.

Doc from java.io.DataInput.readBoolean.

Reads one input byte and returns true if that byte is nonzero, false if that byte is zero. This method is suitable for reading the byte written by the writeBoolean method of interface DataOutput.

Exceptions
IOException:
if an I/O error occurs.
readByteback to summary
public byte readByte() throws IOException

Implements java.io.DataInput.readByte.

Doc from java.io.DataInput.readByte.

Reads and returns one input byte. The byte is treated as a signed value in the range -128 through 127, inclusive. This method is suitable for reading the byte written by the writeByte method of interface DataOutput.

Exceptions
IOException:
if an I/O error occurs.
readCharback to summary
public char readChar() throws IOException

Implements java.io.DataInput.readChar.

Doc from java.io.DataInput.readChar.

Reads two input bytes and returns a char value. Let a be the first byte read and b be the second byte. The value returned is:

(char)((a << 8) | (b & 0xff))
This method is suitable for reading bytes written by the writeChar method of interface DataOutput.
Exceptions
IOException:
if an I/O error occurs.
readDoubleback to summary
public final double readDouble() throws IOException

Implements java.io.DataInput.readDouble.

Doc from java.io.DataInput.readDouble.

Reads eight input bytes and returns a double value. It does this by first constructing a long value in exactly the manner of the readLong method, then converting this long value to a double in exactly the manner of the method Double.longBitsToDouble. This method is suitable for reading bytes written by the writeDouble method of interface DataOutput.

Exceptions
IOException:
if an I/O error occurs.
readFloatback to summary
public final float readFloat() throws IOException

Implements java.io.DataInput.readFloat.

Doc from java.io.DataInput.readFloat.

Reads four input bytes and returns a float value. It does this by first constructing an int value in exactly the manner of the readInt method, then converting this int value to a float in exactly the manner of the method Float.intBitsToFloat. This method is suitable for reading bytes written by the writeFloat method of interface DataOutput.

Exceptions
IOException:
if an I/O error occurs.
readFullyback to summary
public void readFully(byte[] b) throws IOException

Implements java.io.DataInput.readFully.

Doc from java.io.DataInput.readFully.

Reads some bytes from an input stream and stores them into the buffer array b. The number of bytes read is equal to the length of b.

This method blocks until one of the following conditions occurs:

  • b.length bytes of input data are available, in which case a normal return is made.
  • End of file is detected, in which case an EOFException is thrown.
  • An I/O error occurs, in which case an IOException other than EOFException is thrown.

If b is null, a NullPointerException is thrown. If b.length is zero, then no bytes are read. Otherwise, the first byte read is stored into element b[0], the next one into b[1], and so on. If an exception is thrown from this method, then it may be that some but not all bytes of b have been updated with data from the input stream.

Exceptions
IOException:
if an I/O error occurs.
readFullyback to summary
public final void readFully(byte[] b, int off, int len) throws IOException

Implements java.io.DataInput.readFully.

Doc from java.io.DataInput.readFully.

Reads len bytes from an input stream.

This method blocks until one of the following conditions occurs:

  • len bytes of input data are available, in which case a normal return is made.
  • End of file is detected, in which case an EOFException is thrown.
  • An I/O error occurs, in which case an IOException other than EOFException is thrown.

If b is null, a NullPointerException is thrown. If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown. If len is zero, then no bytes are read. Otherwise, the first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len.

Exceptions
IOException:
if an I/O error occurs.
readIntback to summary
public int readInt() throws IOException

Implements java.io.DataInput.readInt.

Doc from java.io.DataInput.readInt.

Reads four input bytes and returns an int value. Let a-d be the first through fourth bytes read. The value returned is:

(((a & 0xff) << 24) | ((b & 0xff) << 16) |
 ((c & 0xff) <<  8) | (d & 0xff))
This method is suitable for reading bytes written by the writeInt method of interface DataOutput.
Exceptions
IOException:
if an I/O error occurs.
readLineback to summary
public String readLine()

Implements java.io.DataInput.readLine.

Doc from java.io.DataInput.readLine.

Reads the next line of text from the input stream. It reads successive bytes, converting each byte separately into a character, until it encounters a line terminator or end of file; the characters read are then returned as a String. Note that because this method processes bytes, it does not support input of the full Unicode character set.

If end of file is encountered before even one byte can be read, then null is returned. Otherwise, each byte that is read is converted to type char by zero-extension. If the character '\n' is encountered, it is discarded and reading ceases. If the character '\r' is encountered, it is discarded and, if the following byte converts to the character '\n', then that is discarded also; reading then ceases. If end of file is encountered before either of the characters '\n' and '\r' is encountered, reading ceases. Once reading has ceased, a String is returned that contains all the characters read and not discarded, taken in order. Note that every character in this string will have a value less than \u0100, that is, (char)256.

readLongback to summary
public long readLong() throws IOException

Implements java.io.DataInput.readLong.

Doc from java.io.DataInput.readLong.

Reads eight input bytes and returns a long value. Let a-h be the first through eighth bytes read. The value returned is:

(((long)(a & 0xff) << 56) |
 ((long)(b & 0xff) << 48) |
 ((long)(c & 0xff) << 40) |
 ((long)(d & 0xff) << 32) |
 ((long)(e & 0xff) << 24) |
 ((long)(f & 0xff) << 16) |
 ((long)(g & 0xff) <<  8) |
 ((long)(h & 0xff)))

This method is suitable for reading bytes written by the writeLong method of interface DataOutput.

Exceptions
IOException:
if an I/O error occurs.
readShortback to summary
public short readShort() throws IOException

Implements java.io.DataInput.readShort.

Doc from java.io.DataInput.readShort.

Reads two input bytes and returns a short value. Let a be the first byte read and b be the second byte. The value returned is:

(short)((a << 8) | (b & 0xff))
This method is suitable for reading the bytes written by the writeShort method of interface DataOutput.
Exceptions
IOException:
if an I/O error occurs.
readUnsignedByteback to summary
public final int readUnsignedByte() throws IOException

Implements java.io.DataInput.readUnsignedByte.

Doc from java.io.DataInput.readUnsignedByte.

Reads one input byte, zero-extends it to type int, and returns the result, which is therefore in the range 0 through 255. This method is suitable for reading the byte written by the writeByte method of interface DataOutput if the argument to writeByte was intended to be a value in the range 0 through 255.

Exceptions
IOException:
if an I/O error occurs.
readUnsignedShortback to summary
public final int readUnsignedShort() throws IOException

Implements java.io.DataInput.readUnsignedShort.

Doc from java.io.DataInput.readUnsignedShort.

Reads two input bytes and returns an int value in the range 0 through 65535. Let a be the first byte read and b be the second byte. The value returned is:

(((a & 0xff) << 8) | (b & 0xff))
This method is suitable for reading the bytes written by the writeShort method of interface DataOutput if the argument to writeShort was intended to be a value in the range 0 through 65535.
Exceptions
IOException:
if an I/O error occurs.
readUTFback to summary
public String readUTF() throws IOException

Implements java.io.DataInput.readUTF.

Doc from java.io.DataInput.readUTF.

Reads in a string that has been encoded using a modified UTF-8 format. The general contract of readUTF is that it reads a representation of a Unicode character string encoded in modified UTF-8 format; this string of characters is then returned as a String.

First, two bytes are read and used to construct an unsigned 16-bit integer in exactly the manner of the readUnsignedShort method . This integer value is called the UTF length and specifies the number of additional bytes to be read. These bytes are then converted to characters by considering them in groups. The length of each group is computed from the value of the first byte of the group. The byte following a group, if any, is the first byte of the next group.

If the first byte of a group matches the bit pattern 0xxxxxxx (where x means "may be 0 or 1"), then the group consists of just that byte. The byte is zero-extended to form a character.

If the first byte of a group matches the bit pattern 110xxxxx, then the group consists of that byte a and a second byte b. If there is no byte b (because byte a was the last of the bytes to be read), or if byte b does not match the bit pattern 10xxxxxx, then a UTFDataFormatException is thrown. Otherwise, the group is converted to the character:

(char)(((a & 0x1F) << 6) | (b & 0x3F))
If the first byte of a group matches the bit pattern 1110xxxx, then the group consists of that byte a and two more bytes b and c. If there is no byte c (because byte a was one of the last two of the bytes to be read), or either byte b or byte c does not match the bit pattern 10xxxxxx, then a UTFDataFormatException is thrown. Otherwise, the group is converted to the character:
(char)(((a & 0x0F) << 12) | ((b & 0x3F) << 6) | (c & 0x3F))
If the first byte of a group matches the pattern 1111xxxx or the pattern 10xxxxxx, then a UTFDataFormatException is thrown.

If end of file is encountered at any time during this entire process, then an EOFException is thrown.

After every group has been converted to a character by this process, the characters are gathered, in the same order in which their corresponding groups were read from the input stream, to form a String, which is returned.

The writeUTF method of interface DataOutput may be used to write data that is suitable for reading by this method.

Exceptions
IOException:
if an I/O error occurs.
resetback to summary
public void reset()

Overrides java.io.InputStream.reset.

Doc from java.io.InputStream.reset.

Repositions this stream to the position at the time the mark method was last called on this input stream.

The general contract of reset is:

  • If the method markSupported returns true, then:
    • If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown.
    • If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
  • If the method markSupported returns false, then:
    • The call to reset may throw an IOException.
    • If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.
skipback to summary
public long skip(long n)

Overrides java.io.InputStream.skip.

Doc from java.io.InputStream.skip.

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, the skip method for class InputStream always returns 0, and no bytes are skipped. Subclasses may handle the negative value differently.

skipBytesback to summary
public int skipBytes(int n)

Implements java.io.DataInput.skipBytes.

Doc from java.io.DataInput.skipBytes.

Makes an attempt to skip over n bytes of data from the input stream, discarding the skipped bytes. However, it may skip over some smaller number of bytes, possibly zero. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. This method never throws an EOFException. The actual number of bytes skipped is returned.