Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.iapi.services.io.ArrayInputStream

Modifier and Type	Field and Description
private int	end
private ErrorObjectInput	oi
private byte[]	pageData
private int	position
private int	start

Access	Constructor and Description
public	ArrayInputStream() Create an ArrayInputStream with a zero length byte array.
public	ArrayInputStream(byte[] The data in the stream data) Create an ArrayInputStream with the passed in data.

Method Summary

Modifier and Type	Method and Description
public int	available() Overrides java.io.InputStream.available. Implements java.io.ObjectInput.available. Returns the number of bytes that can be read without blocking.
public final int	clearLimit() Implements org.apache.derby.iapi.services.io.Limit.clearLimit. Clears the limit by setting the limit to be the entire byte array.
public byte[]	Returns: the data in the stream getData() Return a reference to the array of bytes this stream is going to read from so that caller may load it with stuff
public String	getErrorInfo() Implements org.apache.derby.iapi.services.io.ErrorObjectInput.getErrorInfo.
public Exception	getNestedException() Implements org.apache.derby.iapi.services.io.ErrorObjectInput.getNestedException.
public int	getPosition()
public int	read() Implements abstract java.io.InputStream.read. Implements java.io.ObjectInput.read. Reads a byte of data.
public int	read(byte[] the buffer into which the data is read b, int the start offset of the data off, int the maximum number of bytes read len) Overrides java.io.InputStream.read. Implements java.io.ObjectInput.read. Reads into an array of bytes.
public final 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 final byte	readByte() Implements java.io.DataInput.readByte. Reads and returns one input byte.
public final char	readChar() Implements java.io.DataInput.readChar. Reads two input bytes and returns a `char` value.
public final int	Returns: the uncompressed int readCompressedInt() Read a compressed int from the stream.
public final long	Returns: the uncompressed long readCompressedLong() Read a compressed long from the stream.
public final int	Returns: The the number of valid char's in the returned char[]. readDerbyUTF(char[][] This parameter uses a element array to implement an in/out function parameter. The char[] array in rawData_array[0] is used to read the data into unless it is not big enough, then a new array is allocated and the old one discarded. In either case on return rawData_array[0] contains the filled in char[] - caller must allow that the array may or may not be different from the one passed in. rawData_array, int the byte length of the value, or `0` if unknown utflen) read in a Derby UTF formated string into a char[].
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 final void	readFully(byte[] the buffer into which the data is read. 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[] the buffer into which the data is read. b, int an int specifying the offset in the data array `b`. off, int an int specifying the number of bytes to read. len) Implements java.io.DataInput.readFully. Reads `len` bytes from an input stream.
public final int	readInt() Implements java.io.DataInput.readInt. Reads four input bytes and returns an `int` value.
public final String	readLine() Implements java.io.DataInput.readLine. Reads the next line of text from the input stream.
public final long	readLong() Implements java.io.DataInput.readLong. Reads eight input bytes and returns a `long` value.
public Object	readObject() Implements java.io.ObjectInput.readObject. Read and return an object.
public final 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 final String	readUTF() Implements java.io.DataInput.readUTF. Reads in a string that has been encoded using a modified UTF-8 format.
public void	setData(byte[] The data in the stream data) Set the array of bytes to be read.
public void	setLimit(int Offset into the stream offset, int New length length) A setLimit which also sets the position to be offset.
public final void	setLimit(int The length to set length) Implements org.apache.derby.iapi.services.io.Limit.setLimit. Set the limit of the data that can be read or written.
public final void	setPosition(int newPosition)
public long	Returns: the number of bytes that were skipped skip(long the number of bytes to skip count) Overrides java.io.InputStream.skip. Implements java.io.ObjectInput.skip. Skip as many bytes as possible, but no more than `count`.
public final int	Returns: the number of bytes that were skipped skipBytes(int the number of bytes to skip n) Implements java.io.DataInput.skipBytes. Skip as many bytes as possible, but no more than `n`.

Inherited from java.io.InputStream:: close mark markSupported nullInputStream read readAllBytes readNBytes readNBytes reset skipNBytes transferTo

end	back to summary
private int end

oi	back to summary
private ErrorObjectInput oi

pageData	back to summary
private byte[] pageData

position	back to summary
private int position

start	back to summary
private int start

ArrayInputStream	back to summary
public ArrayInputStream() Create an ArrayInputStream with a zero length byte array. The position is set to 0 and the limit is the entire byte array.

ArrayInputStream	back to summary
public ArrayInputStream(byte[] data) Create an ArrayInputStream with the passed in data. The position is set to 0 and the limit is the entire byte array. Parameters data:byte[] The data in the stream

Method Detail

available	back to summary
public int available() throws IOException Overrides java.io.InputStream.available. Implements java.io.ObjectInput.available. Doc from java.io.ObjectInput.available. Returns the number of bytes that can be read without blocking. Returns:int the number of available bytes. Exceptions IOException: If an I/O error has occurred.

available

back to summary

public int available() throws IOException

Overrides java.io.InputStream.available.

Implements java.io.ObjectInput.available.

Doc from java.io.ObjectInput.available.

Returns the number of bytes that can be read without blocking.

Returns:int

the number of available bytes.

Exceptions

IOException:: If an I/O error has occurred.

clearLimit back to summary

clearLimit	back to summary
public final int clearLimit() Implements org.apache.derby.iapi.services.io.Limit.clearLimit. Clears the limit by setting the limit to be the entire byte array. Returns:int Doc from org.apache.derby.iapi.services.io.Limit.clearLimit. the number of bytes within the limit that have not been read or written. See Also `Limit#clearLimit`

public final int clearLimit()

Implements org.apache.derby.iapi.services.io.Limit.clearLimit.

Clears the limit by setting the limit to be the entire byte array.

Returns:int

Doc from org.apache.derby.iapi.services.io.Limit.clearLimit.

the number of bytes within the limit that have not been read or written.

See Also

Limit#clearLimit

getData	back to summary
public byte[] getData() Return a reference to the array of bytes this stream is going to read from so that caller may load it with stuff Returns:byte[] the data in the stream

getData

back to summary

public byte[] getData()

Return a reference to the array of bytes this stream is going to read from so that caller may load it with stuff

Returns:byte[]: the data in the stream

getErrorInfo	back to summary
public String getErrorInfo() Implements org.apache.derby.iapi.services.io.ErrorObjectInput.getErrorInfo.

getNestedException	back to summary
public Exception getNestedException() Implements org.apache.derby.iapi.services.io.ErrorObjectInput.getNestedException.

getPosition	back to summary
public int getPosition()

read	back to summary
public int read() throws IOException Implements abstract java.io.InputStream.read. Implements java.io.ObjectInput.read. Doc from java.io.ObjectInput.read. Reads a byte of data. This method will block if no input is available. Returns:int the byte read, or -1 if the end of the stream is reached. Exceptions IOException: If an I/O error has occurred.

read

back to summary

public int read() throws IOException

Implements abstract java.io.InputStream.read.

Implements java.io.ObjectInput.read.

Doc from java.io.ObjectInput.read.

Reads a byte of data. This method will block if no input is available.

Returns:int

the byte read, or -1 if the end of the stream is reached.

Exceptions

IOException:: If an I/O error has occurred.

read back to summary

read	back to summary
public int read(byte[] b, int off, int len) throws IOException Overrides java.io.InputStream.read. Implements java.io.ObjectInput.read. Doc from java.io.ObjectInput.read. Reads into an array of bytes. This method will block until some input is available. Parameters b:byte[] the buffer into which the data is read off:int the start offset of the data len:int the maximum number of bytes read Returns:int the total number of bytes read into the buffer, or `-1` if there is no more data because the end of the stream has been reached. Exceptions IOException: If an I/O error has occurred.

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

Overrides java.io.InputStream.read.

Implements java.io.ObjectInput.read.

Doc from java.io.ObjectInput.read.

Reads into an array of bytes. This method will block until some input is available.

Parameters

b:byte[]: the buffer into which the data is read
off:int: the start offset of the data
len:int: the maximum number of bytes read

Returns:int

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Exceptions

IOException:: If an I/O error has occurred.

readBoolean back to summary

readBoolean	back to summary
public final 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`. Returns:boolean the `boolean` value read. Exceptions IOException: if an I/O error occurs.

public final 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.

Returns:boolean

the boolean value read.

Exceptions

IOException:: if an I/O error occurs.

readByte back to summary

readByte	back to summary
public final 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`. Returns:byte the 8-bit value read. Exceptions IOException: if an I/O error occurs.

public final 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.

Returns:byte

the 8-bit value read.

Exceptions

IOException:: if an I/O error occurs.

readChar back to summary

readChar	back to summary
public final 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`. Returns:char the `char` value read. Exceptions IOException: if an I/O error occurs.

public final 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.

Returns:char

the char value read.

Exceptions

IOException:: if an I/O error occurs.

readCompressedInt	back to summary
public final int readCompressedInt() throws IOException Read a compressed int from the stream. Read a compressed int from the stream, which is assumed to have been written by a call to CompressNumber.writeInt(). Code from CompressedNumber is inlined here so that these fields can be read from the array with a minimum of function calls. The format of a compressed int is as follows: Formats are (with x representing value bits): 1 Byte- 00xxxxxx val <= 63 (0x3f) 2 Byte- 01xxxxxx xxxxxxxx val > 63 && <= 16383 (0x3fff) 4 byte- 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx val > 16383 && <= MAX_INT Returns:int the uncompressed int Exceptions IOException: if an I/O error happens

readCompressedInt

back to summary

public final int readCompressedInt() throws IOException

Read a compressed int from the stream.

Read a compressed int from the stream, which is assumed to have been written by a call to CompressNumber.writeInt().

Code from CompressedNumber is inlined here so that these fields can be read from the array with a minimum of function calls.

The format of a compressed int is as follows: Formats are (with x representing value bits):

1 Byte- 00xxxxxx                            val <= 63 (0x3f)
2 Byte- 01xxxxxx xxxxxxxx                   val > 63 && <= 16383 (0x3fff)
4 byte- 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx val > 16383 && <= MAX_INT

Returns:int

the uncompressed int

Exceptions

IOException:: if an I/O error happens

readCompressedLong	back to summary
public final long readCompressedLong() throws IOException Read a compressed long from the stream. Read a compressed long from the stream, which is assumed to have been written by a call to CompressNumber.writeLong(). Code from CompressedNumber is inlined here so that these fields can be read from the array with a minimum of function calls. The format of a compressed int is as follows: Formats are (with x representing value bits): value >= 16383 (0x3fff): 2 byte - 00xxxxxx xxxxxxxx value > 16383 && <= 0x3fffffff: 4 byte - 01xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx value < 0x3fffffff &< <= MAX_LONG: 8 byte - 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx Returns:long the uncompressed long Exceptions IOException: on error

readCompressedLong

back to summary

public final long readCompressedLong() throws IOException

Read a compressed long from the stream.

Read a compressed long from the stream, which is assumed to have been written by a call to CompressNumber.writeLong().

Code from CompressedNumber is inlined here so that these fields can be read from the array with a minimum of function calls.

The format of a compressed int is as follows: Formats are (with x representing value bits):

value >= 16383 (0x3fff): 
    2 byte - 00xxxxxx xxxxxxxx 

value > 16383 && <= 0x3fffffff:
    4 byte - 01xxxxxx xxxxxxxx xxxxxxxx xxxxxxxx

value < 0x3fffffff &< <= MAX_LONG:
    8 byte - 1xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx

Returns:long

the uncompressed long

Exceptions

IOException:: on error

readDerbyUTF back to summary

readDerbyUTF	back to summary
public final int readDerbyUTF(char[][] rawData_array, int utflen) throws IOException read in a Derby UTF formated string into a char[]. This routine inline's the code to read a UTF format string from a byte[] array (pageData), into a char[] array. The string will be read into the char[] array passed into this routine through rawData_array[0] if it is big enough. If it is not big enough a new char[] will be alocated and returned to the caller by putting it into rawData_array[0]. To see detailed description of the Derby UTF format see the writeExternal() routine of SQLChar. The routine returns the number of char's read into the returned char[], note that this length may smaller than the actual length of the char[] array. The stream must be positioned on the first user byte when this method is invoked. Parameters rawData_array:char[][] This parameter uses a element array to implement an in/out function parameter. The char[] array in rawData_array[0] is used to read the data into unless it is not big enough, then a new array is allocated and the old one discarded. In either case on return rawData_array[0] contains the filled in char[] - caller must allow that the array may or may not be different from the one passed in. utflen:int the byte length of the value, or `0` if unknown Returns:int The the number of valid char's in the returned char[]. Exceptions IOException: if an I/O error happens

public final int readDerbyUTF(char[][] rawData_array, int utflen) throws IOException

read in a Derby UTF formated string into a char[].

This routine inline's the code to read a UTF format string from a byte[] array (pageData), into a char[] array. The string will be read into the char[] array passed into this routine through rawData_array[0] if it is big enough. If it is not big enough a new char[] will be alocated and returned to the caller by putting it into rawData_array[0].

To see detailed description of the Derby UTF format see the writeExternal() routine of SQLChar.

The routine returns the number of char's read into the returned char[], note that this length may smaller than the actual length of the char[] array.

The stream must be positioned on the first user byte when this method is invoked.

Parameters

rawData_array:char[][]: This parameter uses a element array to implement an in/out function parameter. The char[] array in rawData_array[0] is used to read the data into unless it is not big enough, then a new array is allocated and the old one discarded. In either case on return rawData_array[0] contains the filled in char[] - caller must allow that the array may or may not be different from the one passed in.
utflen:int: the byte length of the value, or 0 if unknown

Returns:int

The the number of valid char's in the returned char[].

Exceptions

IOException:: if an I/O error happens

readDouble back to summary

readDouble	back 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`. Returns:double the `double` value read. Exceptions IOException: if an I/O error occurs.

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.

Returns:double

the double value read.

Exceptions

IOException:: if an I/O error occurs.

readFloat back to summary

readFloat	back 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`. Returns:float the `float` value read. Exceptions IOException: if an I/O error occurs.

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.

Returns:float

the float value read.

Exceptions

IOException:: if an I/O error occurs.

readFully back to summary

readFully	back to summary
public final 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. Parameters b:byte[] the buffer into which the data is read. Exceptions IOException: if an I/O error occurs.

public final 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.

Parameters

b:byte[]: the buffer into which the data is read.

Exceptions

IOException:: if an I/O error occurs.

readFully back to summary

readFully	back 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`. Parameters b:byte[] the buffer into which the data is read. off:int an int specifying the offset in the data array `b`. len:int an int specifying the number of bytes to read. Exceptions IOException: if an I/O error occurs.

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.

Parameters

b:byte[]: the buffer into which the data is read.
off:int: an int specifying the offset in the data array b.
len:int: an int specifying the number of bytes to read.

Exceptions

IOException:: if an I/O error occurs.

readInt back to summary

readInt	back to summary
public final 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`. Returns:int the `int` value read. Exceptions IOException: if an I/O error occurs.

public final 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.

Returns:int

the int value read.

Exceptions

IOException:: if an I/O error occurs.

readLine back to summary

readLine	back to summary
public final String readLine() throws IOException 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`. Returns:String the next line of text from the input stream, or `null` if the end of file is encountered before a byte can be read. Exceptions IOException: if an I/O error occurs.

public final String readLine() throws IOException

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.

Returns:String

the next line of text from the input stream, or null if the end of file is encountered before a byte can be read.

Exceptions

IOException:: if an I/O error occurs.

readLong back to summary

readLong	back to summary
public final 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`. Returns:long the `long` value read. Exceptions IOException: if an I/O error occurs.

public final 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.

Returns:long

the long value read.

Exceptions

IOException:: if an I/O error occurs.

readObject	back to summary
public Object readObject() throws ClassNotFoundException, IOException Implements java.io.ObjectInput.readObject. Doc from java.io.ObjectInput.readObject. Read and return an object. The class that implements this interface defines where the object is "read" from. Returns:Object the object read from the stream Exceptions ClassNotFoundException: If the class of a serialized object cannot be found. IOException: If any of the usual Input/Output related exceptions occur.

readObject

back to summary

public Object readObject() throws ClassNotFoundException, IOException

Implements java.io.ObjectInput.readObject.

Doc from java.io.ObjectInput.readObject.

Read and return an object. The class that implements this interface defines where the object is "read" from.

Returns:Object

the object read from the stream

Exceptions

ClassNotFoundException:: If the class of a serialized object cannot be found.
IOException:: If any of the usual Input/Output related exceptions occur.

readShort back to summary

readShort	back to summary
public final 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`. Returns:short the 16-bit value read. Exceptions IOException: if an I/O error occurs.

public final 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.

Returns:short

the 16-bit value read.

Exceptions

IOException:: if an I/O error occurs.

readUnsignedByte back to summary

readUnsignedByte	back 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`. Returns:int the unsigned 8-bit value read. Exceptions IOException: if an I/O error occurs.

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.

Returns:int

the unsigned 8-bit value read.

Exceptions

IOException:: if an I/O error occurs.

readUnsignedShort back to summary

readUnsignedShort	back 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`. Returns:int the unsigned 16-bit value read. Exceptions IOException: if an I/O error occurs.

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.

Returns:int

the unsigned 16-bit value read.

Exceptions

IOException:: if an I/O error occurs.

readUTF back to summary

readUTF	back to summary
public final 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. Returns:String a Unicode string. Exceptions IOException: if an I/O error occurs.

public final 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.

Returns:String

a Unicode string.

Exceptions

IOException:: if an I/O error occurs.

setData	back to summary
public void setData(byte[] data) Set the array of bytes to be read. Position is set to zero. Parameters data:byte[] The data in the stream

setData

back to summary

public void setData(byte[] data)

Set the array of bytes to be read. Position is set to zero.

Parameters

data:byte[]: The data in the stream

setLimit	back to summary
public void setLimit(int offset, int length) throws IOException A setLimit which also sets the position to be offset. Parameters offset:int Offset into the stream length:int New length Exceptions IOException: limit is out of range

setLimit

back to summary

public void setLimit(int offset, int length) throws IOException

A setLimit which also sets the position to be offset.

Parameters

offset:int: Offset into the stream
length:int: New length

Exceptions

IOException:: limit is out of range

setLimit	back to summary
public final void setLimit(int length) throws IOException Implements org.apache.derby.iapi.services.io.Limit.setLimit. Doc from org.apache.derby.iapi.services.io.Limit.setLimit. Set the limit of the data that can be read or written. After this call up to and including length bytes can be read from or skipped in the stream. On input classes (e.g. InputStreams) any attempt to read or skip beyond the limit will result in an end of file indication (e.g. read() methods returning -1 or throwing EOFException). On output classes (e.g. OutputStream) any attempt to write more beyond the limit will result in an EOFException Parameters length:int The length to set Exceptions IOException: IOException from some underlying stream

setLimit

back to summary

public final void setLimit(int length) throws IOException

Implements org.apache.derby.iapi.services.io.Limit.setLimit.

Doc from org.apache.derby.iapi.services.io.Limit.setLimit.

Set the limit of the data that can be read or written. After this call up to and including length bytes can be read from or skipped in the stream.

On input classes (e.g. InputStreams) any attempt to read or skip beyond the limit will result in an end of file indication (e.g. read() methods returning -1 or throwing EOFException).

On output classes (e.g. OutputStream) any attempt to write more beyond the limit will result in an EOFException

Parameters

length:int: The length to set

Exceptions

IOException:: IOException from some underlying stream

setPosition	back to summary
public final void setPosition(int newPosition) throws IOException

skip back to summary

skip	back to summary
public long skip(long count) throws IOException Overrides java.io.InputStream.skip. Implements java.io.ObjectInput.skip. Skip as many bytes as possible, but no more than `count`. Parameters count:long the number of bytes to skip Returns:long the number of bytes that were skipped Exceptions IOException: Doc from java.io.ObjectInput.skip. If an I/O error has occurred.

public long skip(long count) throws IOException

Overrides java.io.InputStream.skip.

Implements java.io.ObjectInput.skip.

Skip as many bytes as possible, but no more than count.

Parameters

count:long: the number of bytes to skip

Returns:long

the number of bytes that were skipped

Exceptions

IOException:

Doc from java.io.ObjectInput.skip.

If an I/O error has occurred.

skipBytes back to summary

skipBytes	back to summary
public final int skipBytes(int n) throws IOException Implements java.io.DataInput.skipBytes. Skip as many bytes as possible, but no more than `n`. Parameters n:int the number of bytes to skip Returns:int the number of bytes that were skipped Exceptions IOException: Doc from java.io.DataInput.skipBytes. if an I/O error occurs.

public final int skipBytes(int n) throws IOException

Implements java.io.DataInput.skipBytes.

Skip as many bytes as possible, but no more than n.

Parameters

n:int: the number of bytes to skip

Returns:int

the number of bytes that were skipped

Exceptions

IOException:

Doc from java.io.DataInput.skipBytes.

if an I/O error occurs.

public final Class ArrayInputStream

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