Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.io.vfmem.VirtualRandomAccessFile

Modifier and Type	Field and Description
private final boolean	_readOnly whether the file is read-only
private final BlockedByteArrayInputStream	bIn Stream used to read from the source entry.
private final BlockedByteArrayOutputStream	bOut Stream used to write into the source entry.
private final DataInputStream	dIs Data input stream on top of the source input stream.
private final DataOutputStream	dOs Data output stream on top of the source output stream.
private final DataStoreEntry	entry The source entry.
private long	fp Current position / file pointer.

Access	Constructor and Description
public	VirtualRandomAccessFile(DataStoreEntry the source entry entry, boolean if the file should be opened read-only or not readOnly) Creates a new virtual random access file.

Method Summary

Modifier and Type	Method and Description
public VirtualRandomAccessFile	clone() Overrides java.lang.Object.clone. Implements org.apache.derby.io.StorageRandomAccessFile.clone. Clone this file abstraction
public void	close() Implements org.apache.derby.io.StorageRandomAccessFile.close. Closes this file.
public long	getFilePointer() Implements org.apache.derby.io.StorageRandomAccessFile.getFilePointer. Get the current offset in this file.
public long	length() Implements org.apache.derby.io.StorageRandomAccessFile.length. Gets the length of this file.
public int	read(byte[] the buffer into which the data is read. b, int the start offset in array `b` at which the data is written. off, int the maximum number of bytes read. len) Implements org.apache.derby.io.StorageRandomAccessFile.read. Reads up to `len` bytes of data from this file 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 double	readDouble() Implements java.io.DataInput.readDouble. Reads eight input bytes and returns a `double` value.
public float	readFloat() Implements java.io.DataInput.readFloat. Reads four input bytes and returns a `float` value.
public 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 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 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 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 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	seek(long the new file pointer, measured in bytes from the beginning of the file. newFilePointer) Implements org.apache.derby.io.StorageRandomAccessFile.seek. Set the file pointer.
public void	setLength(long The new file length. newLength) Implements org.apache.derby.io.StorageRandomAccessFile.setLength. Sets the length of this file, either extending or truncating it.
public int	skipBytes(int the number of bytes to be skipped. n) Implements java.io.DataInput.skipBytes. Makes an attempt to skip over `n` bytes of data from the input stream, discarding the skipped bytes.
public void	sync() Implements org.apache.derby.io.StorageRandomAccessFile.sync. Force any changes out to the persistent store.
public void	write(int the byte to be written. b) Implements java.io.DataOutput.write. Writes to the output stream the eight low-order bits of the argument `b`.
public void	write(byte[] the data. b) Implements java.io.DataOutput.write. Writes to the output stream all the bytes in array `b`.
public void	write(byte[] the data. b, int the start offset in the data. off, int the number of bytes to write. len) Implements java.io.DataOutput.write. Writes `len` bytes from array `b`, in order, to the output stream.
public void	writeBoolean(boolean the boolean to be written. v) Implements java.io.DataOutput.writeBoolean. Writes a `boolean` value to this output stream.
public void	writeByte(int the byte value to be written. v) Implements java.io.DataOutput.writeByte. Writes to the output stream the eight low-order bits of the argument `v`.
public void	writeBytes(String the string of bytes to be written. s) Implements java.io.DataOutput.writeBytes. Writes a string to the output stream.
public void	writeChar(int the `char` value to be written. v) Implements java.io.DataOutput.writeChar. Writes a `char` value, which is comprised of two bytes, to the output stream.
public void	writeChars(String the string value to be written. s) Implements java.io.DataOutput.writeChars. Writes every character in the string `s`, to the output stream, in order, two bytes per character.
public void	writeDouble(double the `double` value to be written. v) Implements java.io.DataOutput.writeDouble. Writes a `double` value, which is comprised of eight bytes, to the output stream.
public void	writeFloat(float the `float` value to be written. v) Implements java.io.DataOutput.writeFloat. Writes a `float` value, which is comprised of four bytes, to the output stream.
public void	writeInt(int the `int` value to be written. v) Implements java.io.DataOutput.writeInt. Writes an `int` value, which is comprised of four bytes, to the output stream.
public void	writeLong(long the `long` value to be written. v) Implements java.io.DataOutput.writeLong. Writes a `long` value, which is comprised of eight bytes, to the output stream.
public void	writeShort(int the `short` value to be written. v) Implements java.io.DataOutput.writeShort. Writes two bytes to the output stream to represent the value of the argument.
public void	writeUTF(String the string value to be written. s) Implements java.io.DataOutput.writeUTF. Writes two bytes of length information to the output stream, followed by the modified UTF-8 representation of every character in the string `s`.

Inherited from java.lang.Object:: equals finalize getClass hashCode notify notifyAll toString wait wait wait

_readOnly	back to summary
private final boolean _readOnly whether the file is read-only

bIn	back to summary
private final BlockedByteArrayInputStream bIn Stream used to read from the source entry.

bOut	back to summary
private final BlockedByteArrayOutputStream bOut Stream used to write into the source entry. Will be `null` if the file is opened in read-only mode.

dIs	back to summary
private final DataInputStream dIs Data input stream on top of the source input stream.

dOs	back to summary
private final DataOutputStream dOs Data output stream on top of the source output stream. Will be `null` if the file is opened in read-only mode.

entry	back to summary
private final DataStoreEntry entry The source entry.

fp	back to summary
private long fp Current position / file pointer.

VirtualRandomAccessFile	back to summary
public VirtualRandomAccessFile(DataStoreEntry entry, boolean readOnly) throws FileNotFoundException Creates a new virtual random access file. Parameters entry:DataStoreEntry the source entry readOnly:boolean if the file should be opened read-only or not Exceptions FileNotFoundException: if the denoted path is a directory, or the denoted file has been marked read-only and the file is opened for writing

Method Detail

clone	back to summary
public VirtualRandomAccessFile clone() Overrides java.lang.Object.clone. Implements org.apache.derby.io.StorageRandomAccessFile.clone. Doc from org.apache.derby.io.StorageRandomAccessFile.clone. Clone this file abstraction Returns:VirtualRandomAccessFile Doc from java.lang.Object.clone. a clone of this instance.

clone

back to summary

public VirtualRandomAccessFile clone()

Overrides java.lang.Object.clone.

Implements org.apache.derby.io.StorageRandomAccessFile.clone.

Doc from org.apache.derby.io.StorageRandomAccessFile.clone.

Clone this file abstraction

Returns:VirtualRandomAccessFile

Doc from java.lang.Object.clone.

a clone of this instance.

close	back to summary
public void close() throws IOException Implements org.apache.derby.io.StorageRandomAccessFile.close. Doc from org.apache.derby.io.StorageRandomAccessFile.close. Closes this file. Exceptions IOException: - if an I/O error occurs.

back to summary

public void close() throws IOException

Implements org.apache.derby.io.StorageRandomAccessFile.close.

Doc from org.apache.derby.io.StorageRandomAccessFile.close.

Closes this file.

Exceptions

IOException:: - if an I/O error occurs.

getFilePointer	back to summary
public long getFilePointer() Implements org.apache.derby.io.StorageRandomAccessFile.getFilePointer. Doc from org.apache.derby.io.StorageRandomAccessFile.getFilePointer. Get the current offset in this file. Returns:long the current file pointer.

getFilePointer

back to summary

public long getFilePointer()

Implements org.apache.derby.io.StorageRandomAccessFile.getFilePointer.

Doc from org.apache.derby.io.StorageRandomAccessFile.getFilePointer.

Get the current offset in this file.

Returns:long: the current file pointer.

length	back to summary
public long length() Implements org.apache.derby.io.StorageRandomAccessFile.length. Doc from org.apache.derby.io.StorageRandomAccessFile.length. Gets the length of this file. Returns:long the number of bytes this file.

length

back to summary

public long length()

Implements org.apache.derby.io.StorageRandomAccessFile.length.

Doc from org.apache.derby.io.StorageRandomAccessFile.length.

Gets the length of this file.

Returns:long: the number of bytes this file.

read back to summary

read	back to summary
public int read(byte[] b, int off, int len) throws IOException Implements org.apache.derby.io.StorageRandomAccessFile.read. Doc from org.apache.derby.io.StorageRandomAccessFile.read. Reads up to `len` bytes of data from this file into an array of bytes. This method blocks until at least one byte of input is available. Parameters b:byte[] the buffer into which the data is read. off:int the start offset in array `b` at which the data is written. 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 file has been reached. Exceptions IOException: If the first byte cannot be read for any reason other than end of file, or if the random access file has been closed, or if some other I/O error occurs.

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

Implements org.apache.derby.io.StorageRandomAccessFile.read.

Doc from org.apache.derby.io.StorageRandomAccessFile.read.

Reads up to len bytes of data from this file into an array of bytes. This method blocks until at least one byte of input is available.

Parameters

b:byte[]: the buffer into which the data is read.
off:int: the start offset in array b at which the data is written.
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 file has been reached.

Exceptions

IOException:: If the first byte cannot be read for any reason other than end of file, or if the random access file has been closed, or if some other I/O error occurs.

readBoolean back to summary

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

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.

Returns:boolean

the boolean value read.

Exceptions

IOException:: if an I/O error occurs.

readByte back to summary

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

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.

Returns:byte

the 8-bit value read.

Exceptions

IOException:: if an I/O error occurs.

readChar back to summary

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

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.

Returns:char

the char value read.

Exceptions

IOException:: if an I/O error occurs.

readDouble back to summary

readDouble	back to summary
public 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 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 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 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 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 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 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 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 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 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 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 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 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 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.

readShort back to summary

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

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.

Returns:short

the 16-bit value read.

Exceptions

IOException:: if an I/O error occurs.

readUnsignedByte back to summary

readUnsignedByte	back to summary
public 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 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 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 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 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 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.

seek	back to summary
public void seek(long newFilePointer) throws IOException Implements org.apache.derby.io.StorageRandomAccessFile.seek. Doc from org.apache.derby.io.StorageRandomAccessFile.seek. Set the file pointer. It may be moved beyond the end of the file, but this does not change the length of the file. The length of the file is not changed until data is actually written.. Parameters newFilePointer:long the new file pointer, measured in bytes from the beginning of the file. Exceptions IOException: - if newFilePointer is less than 0 or an I/O error occurs.

seek

back to summary

public void seek(long newFilePointer) throws IOException

Implements org.apache.derby.io.StorageRandomAccessFile.seek.

Doc from org.apache.derby.io.StorageRandomAccessFile.seek.

Set the file pointer. It may be moved beyond the end of the file, but this does not change the length of the file. The length of the file is not changed until data is actually written..

Parameters

newFilePointer:long: the new file pointer, measured in bytes from the beginning of the file.

Exceptions

IOException:: - if newFilePointer is less than 0 or an I/O error occurs.

setLength	back to summary
public void setLength(long newLength) Implements org.apache.derby.io.StorageRandomAccessFile.setLength. Doc from org.apache.derby.io.StorageRandomAccessFile.setLength. Sets the length of this file, either extending or truncating it. If the file is extended then the contents of the extension are not defined. If the file is truncated and the file pointer is greater than the new length then the file pointer is set to the new length. Parameters newLength:long The new file length.

setLength

back to summary

public void setLength(long newLength)

Implements org.apache.derby.io.StorageRandomAccessFile.setLength.

Doc from org.apache.derby.io.StorageRandomAccessFile.setLength.

Sets the length of this file, either extending or truncating it.

If the file is extended then the contents of the extension are not defined.

If the file is truncated and the file pointer is greater than the new length then the file pointer is set to the new length.

Parameters

newLength:long: The new file length.

skipBytes back to summary

skipBytes	back 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. Parameters n:int the number of bytes to be skipped. Returns:int the number of bytes actually skipped.

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.

Parameters

n:int: the number of bytes to be skipped.

Returns:int

the number of bytes actually skipped.

sync	back to summary
public void sync() Implements org.apache.derby.io.StorageRandomAccessFile.sync. Doc from org.apache.derby.io.StorageRandomAccessFile.sync. Force any changes out to the persistent store. If the database is to be transient, that is, if the database does not survive a restart, then the sync method implementation need not do anything.

sync

back to summary

public void sync()

Implements org.apache.derby.io.StorageRandomAccessFile.sync.

Doc from org.apache.derby.io.StorageRandomAccessFile.sync.

Force any changes out to the persistent store. If the database is to be transient, that is, if the database does not survive a restart, then the sync method implementation need not do anything.

write back to summary

write	back to summary
public void write(int b) throws IOException Implements java.io.DataOutput.write. Doc from java.io.DataOutput.write. Writes to the output stream the eight low-order bits of the argument `b`. The 24 high-order bits of `b` are ignored. Parameters b:int the byte to be written. Exceptions IOException: if an I/O error occurs.

public void write(int b) throws IOException

Implements java.io.DataOutput.write.

Doc from java.io.DataOutput.write.

Writes to the output stream the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

Parameters

b:int: the byte to be written.

Exceptions

IOException:: if an I/O error occurs.

write back to summary

write	back to summary
public void write(byte[] b) throws IOException Implements java.io.DataOutput.write. Doc from java.io.DataOutput.write. Writes to the output stream all the bytes in array `b`. If `b` is `null`, a `NullPointerException` is thrown. If `b.length` is zero, then no bytes are written. Otherwise, the byte `b[0]` is written first, then `b[1]`, and so on; the last byte written is `b[b.length-1]`. Parameters b:byte[] the data. Exceptions IOException: if an I/O error occurs.

public void write(byte[] b) throws IOException

Implements java.io.DataOutput.write.

Doc from java.io.DataOutput.write.

Writes to the output stream all the bytes in array b. If b is null, a NullPointerException is thrown. If b.length is zero, then no bytes are written. Otherwise, the byte b[0] is written first, then b[1], and so on; the last byte written is b[b.length-1].

Parameters

b:byte[]: the data.

Exceptions

IOException:: if an I/O error occurs.

write back to summary

write	back to summary
public void write(byte[] b, int off, int len) throws IOException Implements java.io.DataOutput.write. Doc from java.io.DataOutput.write. Writes `len` bytes from array `b`, in order, to the output stream. 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 written. Otherwise, the byte `b[off]` is written first, then `b[off+1]`, and so on; the last byte written is `b[off+len-1]`. Parameters b:byte[] the data. off:int the start offset in the data. len:int the number of bytes to write. Exceptions IOException: if an I/O error occurs.

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

Implements java.io.DataOutput.write.

Doc from java.io.DataOutput.write.

Writes len bytes from array b, in order, to the output stream. 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 written. Otherwise, the byte b[off] is written first, then b[off+1], and so on; the last byte written is b[off+len-1].

Parameters

b:byte[]: the data.
off:int: the start offset in the data.
len:int: the number of bytes to write.

Exceptions

IOException:: if an I/O error occurs.

writeBoolean back to summary

writeBoolean	back to summary
public void writeBoolean(boolean v) throws IOException Implements java.io.DataOutput.writeBoolean. Doc from java.io.DataOutput.writeBoolean. Writes a `boolean` value to this output stream. If the argument `v` is `true`, the value `(byte)1` is written; if `v` is `false`, the value `(byte)0` is written. The byte written by this method may be read by the `readBoolean` method of interface `DataInput`, which will then return a `boolean` equal to `v`. Parameters v:boolean the boolean to be written. Exceptions IOException: if an I/O error occurs.

public void writeBoolean(boolean v) throws IOException

Implements java.io.DataOutput.writeBoolean.

Doc from java.io.DataOutput.writeBoolean.

Writes a boolean value to this output stream. If the argument v is true, the value (byte)1 is written; if v is false, the value (byte)0 is written. The byte written by this method may be read by the readBoolean method of interface DataInput, which will then return a boolean equal to v.

Parameters

v:boolean: the boolean to be written.

Exceptions

IOException:: if an I/O error occurs.

writeByte back to summary

writeByte	back to summary
public void writeByte(int v) throws IOException Implements java.io.DataOutput.writeByte. Doc from java.io.DataOutput.writeByte. Writes to the output stream the eight low-order bits of the argument `v`. The 24 high-order bits of `v` are ignored. (This means that `writeByte` does exactly the same thing as `write` for an integer argument.) The byte written by this method may be read by the `readByte` method of interface `DataInput`, which will then return a `byte` equal to `(byte)v`. Parameters v:int the byte value to be written. Exceptions IOException: if an I/O error occurs.

public void writeByte(int v) throws IOException

Implements java.io.DataOutput.writeByte.

Doc from java.io.DataOutput.writeByte.

Writes to the output stream the eight low-order bits of the argument v. The 24 high-order bits of v are ignored. (This means that writeByte does exactly the same thing as write for an integer argument.) The byte written by this method may be read by the readByte method of interface DataInput, which will then return a byte equal to (byte)v.

Parameters

v:int: the byte value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeBytes back to summary

writeBytes	back to summary
public void writeBytes(String s) throws IOException Implements java.io.DataOutput.writeBytes. Doc from java.io.DataOutput.writeBytes. Writes a string to the output stream. For every character in the string `s`, taken in order, one byte is written to the output stream. If `s` is `null`, a `NullPointerException` is thrown. If `s.length` is zero, then no bytes are written. Otherwise, the character `s[0]` is written first, then `s[1]`, and so on; the last character written is `s[s.length-1]`. For each character, one byte is written, the low-order byte, in exactly the manner of the `writeByte` method . The high-order eight bits of each character in the string are ignored. Parameters s:String the string of bytes to be written. Exceptions IOException: if an I/O error occurs.

public void writeBytes(String s) throws IOException

Implements java.io.DataOutput.writeBytes.

Doc from java.io.DataOutput.writeBytes.

Writes a string to the output stream. For every character in the string s, taken in order, one byte is written to the output stream. If s is null, a NullPointerException is thrown.

If s.length is zero, then no bytes are written. Otherwise, the character s[0] is written first, then s[1], and so on; the last character written is s[s.length-1]. For each character, one byte is written, the low-order byte, in exactly the manner of the writeByte method . The high-order eight bits of each character in the string are ignored.

Parameters

s:String: the string of bytes to be written.

Exceptions

IOException:: if an I/O error occurs.

writeChar back to summary

writeChar	back to summary
public void writeChar(int v) throws IOException Implements java.io.DataOutput.writeChar. Doc from java.io.DataOutput.writeChar. Writes a `char` value, which is comprised of two bytes, to the output stream. The byte values to be written, in the order shown, are: `(byte)(0xff & (v >> 8)) (byte)(0xff & v)` The bytes written by this method may be read by the `readChar` method of interface `DataInput`, which will then return a `char` equal to `(char)v`. Parameters v:int the `char` value to be written. Exceptions IOException: if an I/O error occurs.

public void writeChar(int v) throws IOException

Implements java.io.DataOutput.writeChar.

Doc from java.io.DataOutput.writeChar.

Writes a char value, which is comprised of two bytes, to the output stream. The byte values to be written, in the order shown, are:

(byte)(0xff & (v >> 8))
(byte)(0xff & v)

The bytes written by this method may be read by the readChar method of interface DataInput, which will then return a char equal to (char)v.

Parameters

v:int: the char value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeChars back to summary

writeChars	back to summary
public void writeChars(String s) throws IOException Implements java.io.DataOutput.writeChars. Doc from java.io.DataOutput.writeChars. Writes every character in the string `s`, to the output stream, in order, two bytes per character. If `s` is `null`, a `NullPointerException` is thrown. If `s.length` is zero, then no characters are written. Otherwise, the character `s[0]` is written first, then `s[1]`, and so on; the last character written is `s[s.length-1]`. For each character, two bytes are actually written, high-order byte first, in exactly the manner of the `writeChar` method. Parameters s:String the string value to be written. Exceptions IOException: if an I/O error occurs.

public void writeChars(String s) throws IOException

Implements java.io.DataOutput.writeChars.

Doc from java.io.DataOutput.writeChars.

Writes every character in the string s, to the output stream, in order, two bytes per character. If s is null, a NullPointerException is thrown. If s.length is zero, then no characters are written. Otherwise, the character s[0] is written first, then s[1], and so on; the last character written is s[s.length-1]. For each character, two bytes are actually written, high-order byte first, in exactly the manner of the writeChar method.

Parameters

s:String: the string value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeDouble back to summary

writeDouble	back to summary
public void writeDouble(double v) throws IOException Implements java.io.DataOutput.writeDouble. Doc from java.io.DataOutput.writeDouble. Writes a `double` value, which is comprised of eight bytes, to the output stream. It does this as if it first converts this `double` value to a `long` in exactly the manner of the `Double.doubleToLongBits` method and then writes the `long` value in exactly the manner of the `writeLong` method. The bytes written by this method may be read by the `readDouble` method of interface `DataInput`, which will then return a `double` equal to `v`. Parameters v:double the `double` value to be written. Exceptions IOException: if an I/O error occurs.

public void writeDouble(double v) throws IOException

Implements java.io.DataOutput.writeDouble.

Doc from java.io.DataOutput.writeDouble.

Writes a double value, which is comprised of eight bytes, to the output stream. It does this as if it first converts this double value to a long in exactly the manner of the Double.doubleToLongBits method and then writes the long value in exactly the manner of the writeLong method. The bytes written by this method may be read by the readDouble method of interface DataInput, which will then return a double equal to v.

Parameters

v:double: the double value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeFloat back to summary

writeFloat	back to summary
public void writeFloat(float v) throws IOException Implements java.io.DataOutput.writeFloat. Doc from java.io.DataOutput.writeFloat. Writes a `float` value, which is comprised of four bytes, to the output stream. It does this as if it first converts this `float` value to an `int` in exactly the manner of the `Float.floatToIntBits` method and then writes the `int` value in exactly the manner of the `writeInt` method. The bytes written by this method may be read by the `readFloat` method of interface `DataInput`, which will then return a `float` equal to `v`. Parameters v:float the `float` value to be written. Exceptions IOException: if an I/O error occurs.

public void writeFloat(float v) throws IOException

Implements java.io.DataOutput.writeFloat.

Doc from java.io.DataOutput.writeFloat.

Writes a float value, which is comprised of four bytes, to the output stream. It does this as if it first converts this float value to an int in exactly the manner of the Float.floatToIntBits method and then writes the int value in exactly the manner of the writeInt method. The bytes written by this method may be read by the readFloat method of interface DataInput, which will then return a float equal to v.

Parameters

v:float: the float value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeInt back to summary

writeInt	back to summary
public void writeInt(int v) throws IOException Implements java.io.DataOutput.writeInt. Doc from java.io.DataOutput.writeInt. Writes an `int` value, which is comprised of four bytes, to the output stream. The byte values to be written, in the order shown, are: `(byte)(0xff & (v >> 24)) (byte)(0xff & (v >> 16)) (byte)(0xff & (v >> 8)) (byte)(0xff & v)` The bytes written by this method may be read by the `readInt` method of interface `DataInput`, which will then return an `int` equal to `v`. Parameters v:int the `int` value to be written. Exceptions IOException: if an I/O error occurs.

public void writeInt(int v) throws IOException

Implements java.io.DataOutput.writeInt.

Doc from java.io.DataOutput.writeInt.

Writes an int value, which is comprised of four bytes, to the output stream. The byte values to be written, in the order shown, are:

(byte)(0xff & (v >> 24))
(byte)(0xff & (v >> 16))
(byte)(0xff & (v >>  8))
(byte)(0xff & v)

The bytes written by this method may be read by the readInt method of interface DataInput, which will then return an int equal to v.

Parameters

v:int: the int value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeLong back to summary

writeLong	back to summary
public void writeLong(long v) throws IOException Implements java.io.DataOutput.writeLong. Doc from java.io.DataOutput.writeLong. Writes a `long` value, which is comprised of eight bytes, to the output stream. The byte values to be written, in the order shown, are: `(byte)(0xff & (v >> 56)) (byte)(0xff & (v >> 48)) (byte)(0xff & (v >> 40)) (byte)(0xff & (v >> 32)) (byte)(0xff & (v >> 24)) (byte)(0xff & (v >> 16)) (byte)(0xff & (v >> 8)) (byte)(0xff & v)` The bytes written by this method may be read by the `readLong` method of interface `DataInput`, which will then return a `long` equal to `v`. Parameters v:long the `long` value to be written. Exceptions IOException: if an I/O error occurs.

public void writeLong(long v) throws IOException

Implements java.io.DataOutput.writeLong.

Doc from java.io.DataOutput.writeLong.

Writes a long value, which is comprised of eight bytes, to the output stream. The byte values to be written, in the order shown, are:

(byte)(0xff & (v >> 56))
(byte)(0xff & (v >> 48))
(byte)(0xff & (v >> 40))
(byte)(0xff & (v >> 32))
(byte)(0xff & (v >> 24))
(byte)(0xff & (v >> 16))
(byte)(0xff & (v >>  8))
(byte)(0xff & v)

The bytes written by this method may be read by the readLong method of interface DataInput, which will then return a long equal to v.

Parameters

v:long: the long value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeShort back to summary

writeShort	back to summary
public void writeShort(int v) throws IOException Implements java.io.DataOutput.writeShort. Doc from java.io.DataOutput.writeShort. Writes two bytes to the output stream to represent the value of the argument. The byte values to be written, in the order shown, are: `(byte)(0xff & (v >> 8)) (byte)(0xff & v)` The bytes written by this method may be read by the `readShort` method of interface `DataInput`, which will then return a `short` equal to `(short)v`. Parameters v:int the `short` value to be written. Exceptions IOException: if an I/O error occurs.

public void writeShort(int v) throws IOException

Implements java.io.DataOutput.writeShort.

Doc from java.io.DataOutput.writeShort.

Writes two bytes to the output stream to represent the value of the argument. The byte values to be written, in the order shown, are:

(byte)(0xff & (v >> 8))
(byte)(0xff & v)

The bytes written by this method may be read by the readShort method of interface DataInput, which will then return a short equal to (short)v.

Parameters

v:int: the short value to be written.

Exceptions

IOException:: if an I/O error occurs.

writeUTF back to summary

writeUTF	back to summary
public void writeUTF(String s) throws IOException Implements java.io.DataOutput.writeUTF. Doc from java.io.DataOutput.writeUTF. Writes two bytes of length information to the output stream, followed by the modified UTF-8 representation of every character in the string `s`. If `s` is `null`, a `NullPointerException` is thrown. Each character in the string `s` is converted to a group of one, two, or three bytes, depending on the value of the character. If a character `c` is in the range `\u0001` through `\u007f`, it is represented by one byte: (byte)c If a character `c` is `\u0000` or is in the range `\u0080` through `\u07ff`, then it is represented by two bytes, to be written in the order shown: `(byte)(0xc0 \| (0x1f & (c >> 6))) (byte)(0x80 \| (0x3f & c))` If a character `c` is in the range `\u0800` through `uffff`, then it is represented by three bytes, to be written in the order shown: `(byte)(0xe0 \| (0x0f & (c >> 12))) (byte)(0x80 \| (0x3f & (c >> 6))) (byte)(0x80 \| (0x3f & c))` First, the total number of bytes needed to represent all the characters of `s` is calculated. If this number is larger than `65535`, then a `UTFDataFormatException` is thrown. Otherwise, this length is written to the output stream in exactly the manner of the `writeShort` method; after this, the one-, two-, or three-byte representation of each character in the string `s` is written. The bytes written by this method may be read by the `readUTF` method of interface `DataInput`, which will then return a `String` equal to `s`. Parameters s:String the string value to be written. Exceptions IOException: if an I/O error occurs.

public void writeUTF(String s) throws IOException

Implements java.io.DataOutput.writeUTF.

Doc from java.io.DataOutput.writeUTF.

Writes two bytes of length information to the output stream, followed by the modified UTF-8 representation of every character in the string s. If s is null, a NullPointerException is thrown. Each character in the string s is converted to a group of one, two, or three bytes, depending on the value of the character.

If a character c is in the range \u0001 through \u007f, it is represented by one byte:

(byte)c

If a character c is \u0000 or is in the range \u0080 through \u07ff, then it is represented by two bytes, to be written in the order shown:

(byte)(0xc0 | (0x1f & (c >> 6)))
(byte)(0x80 | (0x3f & c))

If a character c is in the range \u0800 through uffff, then it is represented by three bytes, to be written in the order shown:

(byte)(0xe0 | (0x0f & (c >> 12)))
(byte)(0x80 | (0x3f & (c >>  6)))
(byte)(0x80 | (0x3f & c))

First, the total number of bytes needed to represent all the characters of s is calculated. If this number is larger than 65535, then a UTFDataFormatException is thrown. Otherwise, this length is written to the output stream in exactly the manner of the writeShort method; after this, the one-, two-, or three-byte representation of each character in the string s is written.

The bytes written by this method may be read by the readUTF method of interface DataInput, which will then return a String equal to s.

Parameters

s:String: the string value to be written.

Exceptions

IOException:: if an I/O error occurs.

public Class VirtualRandomAccessFile

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