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# Class java.io.RandomAccessFile

    java.lang.Object
       |
       +----java.io.RandomAccessFile

public class RandomAccessFile
extends Object
implements DataOutput, DataInput

Random access files can be constructed from file descriptors, file names, or file objects. This class provides a sense of security by offering methods that allow specified mode accesses of read-only or read-write to files.

##

RandomAccessFile(File, String)
  Creates a RandomAccessFile from a specified File object and mode ("r" or "rw").
RandomAccessFile(String, String)
  Creates a RandomAccessFile with the specified system dependent file name and the specified mode.

##

close()
  Closes the file.
getFD()
  Returns the opaque file descriptor object.
getFilePointer()
  Returns the current location of the file pointer.
length()
  Returns the length of the file.
read()
  Reads a byte of data.
read(byte[])
  Reads data into an array of bytes.
read(byte[], int, int)
  Reads a sub array as a sequence of bytes.
readBoolean()
  Reads a boolean.
readByte()
  Reads a byte.
readChar()
  Reads a 16 bit char.
readDouble()
  Reads a 64 bit double.
readFloat()
  Reads a 32 bit float.
readFully(byte[])
  Reads bytes, blocking until all bytes are read.
readFully(byte[], int, int)
  Reads bytes, blocking until all bytes are read.
readInt()
  Reads a 32 bit int.
readLine()
  Reads a line terminated by a '\n' or EOF.
readLong()
  Reads a 64 bit long.
readShort()
  Reads 16 bit short.
readUnsignedByte()
  Reads an unsigned 8 bit byte.
readUnsignedShort()
  Reads 16 bit short.
readUTF()
  Reads a UTF formatted String.
seek(long)
  Sets the file pointer to the specified absolute position.
skipBytes(int)
write(byte[])
  Writes an array of bytes.
write(byte[], int, int)
  Wrotes a sub array of bytes.
write(int)
  Writes a byte of data.
writeBoolean(boolean)
  Writes a boolean.
writeByte(int)
  Writes a byte.
writeBytes(String)
  Writes a String as a sequence of bytes.
writeChar(int)
  Writes a character.
writeChars(String)
  Writes a String as a sequence of chars.
writeDouble(double)
writeFloat(float)
writeInt(int)
  Writes an integer.
writeLong(long)
  Writes a long.
writeShort(int)
  Writes a short.
writeUTF(String)
  Writes a String in UTF format.

##

RandomAccessFile

      public RandomAccessFile(String name,
                              String mode) throws IOException

  Creates a RandomAccessFile with the specified system dependent file name and the specified mode. Mode "r" is for read-only and mode "rw" is for read+write.

  Parameters:
    name - the system dependent file name
    mode - the access mode
  Throws: IOException
    If an I/O error has occurred.

RandomAccessFile

      public RandomAccessFile(File file,
                              String mode) throws IOException

  Creates a RandomAccessFile from a specified File object and mode ("r" or "rw").

  Parameters:
    file - the file object
    mode - the access mode

##

getFD

      public final FileDescriptor getFD() throws IOException

  Returns the opaque file descriptor object.

  Returns:
    the file descriptor.

read

      public int read() throws IOException

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

  Returns:
    the byte read, or -1 if the end of the stream is reached.
  Throws: IOException
    If an I/O error has occurred.

read

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

  Reads a sub array as a sequence of bytes.

  Parameters:
    b - the data to be written
    off - the start offset in the data
    len - the number of bytes that are written
  Throws: IOException
    If an I/O error has occurred.

read

      public int read(byte b[]) throws IOException

  Reads data into an array of bytes. This method blocks until some input is available.

  Returns:
    the actual number of bytes read, -1 is returned when the end of the stream is reached.
  Throws: IOException
    If an I/O error has occurred.

readFully

      public final void readFully(byte b[]) throws IOException

  Reads bytes, blocking until all bytes are read.

  Parameters:
    b - the buffer into which the data is read
  Returns:
    the actual number of bytes read, -1 is returned when the end of the stream is reached.
  Throws: IOException
    If an I/O error has occurred.

readFully

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

  Reads bytes, blocking until all bytes are read.

  Parameters:
    b - the buffer into which the data is read
    off - the start offset of the data
    len - the maximum number of bytes read
  Returns:
    the actual number of bytes read, -1 is returned when the end of the stream is reached.
  Throws: IOException
    If an I/O error has occurred.

skipBytes

      public int skipBytes(int n) throws IOException

write

      public void write(int b) throws IOException

  Writes a byte of data. This method will block until the byte is actually written.

  Parameters:
    b - the byte to be written
  Throws: IOException
    If an I/O error has occurred.

write

      public void write(byte b[]) throws IOException

  Writes an array of bytes. Will block until the bytes are actually written.

  Parameters:
    b - the data to be written
  Throws: IOException
    If an I/O error has occurred.

write

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

  Wrotes a sub array of bytes.

  Parameters:
    b - the data to be written
    off - the start offset in the data
    len - the number of bytes that are written
  Throws: IOException
    If an I/O error has occurred.

getFilePointer

      public long getFilePointer() throws IOException

  Returns the current location of the file pointer.

seek

      public void seek(long pos) throws IOException

  Sets the file pointer to the specified absolute position.

  Parameters:
    pos - the absolute position

length

      public long length() throws IOException

  Returns the length of the file.

close

      public void close() throws IOException

  Closes the file.

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

readBoolean

      public final boolean readBoolean() throws IOException

  Reads a boolean.

readByte

      public final byte readByte() throws IOException

  Reads a byte.

readUnsignedByte

      public final int readUnsignedByte() throws IOException

  Reads an unsigned 8 bit byte.

  Returns:
    the 8 bit byte read.

readShort

      public final short readShort() throws IOException

  Reads 16 bit short.

  Returns:
    the read 16 bit short.

readUnsignedShort

      public final int readUnsignedShort() throws IOException

  Reads 16 bit short.

  Returns:
    the read 16 bit short.

readChar

      public final char readChar() throws IOException

  Reads a 16 bit char.

  Returns:
    the read 16 bit char.

readInt

      public final int readInt() throws IOException

  Reads a 32 bit int.

  Returns:
    the read 32 bit integer.

readLong

      public final long readLong() throws IOException

  Reads a 64 bit long.

  Returns:
    the read 64 bit long.

readFloat

      public final float readFloat() throws IOException

  Reads a 32 bit float.

  Returns:
    the read 32 bit float.

readDouble

      public final double readDouble() throws IOException

  Reads a 64 bit double.

  Returns:
    the read 64 bit double.

readLine

      public final String readLine() throws IOException

  Reads a line terminated by a '\n' or EOF.

readUTF

      public final String readUTF() throws IOException

  Reads a UTF formatted String.

writeBoolean

      public final void writeBoolean(boolean v) throws IOException

  Writes a boolean.

  Parameters:
    v - the boolean value

writeByte

      public final void writeByte(int v) throws IOException

  Writes a byte.

  Parameters:
    v - the byte

writeShort

      public final void writeShort(int v) throws IOException

  Writes a short.

  Parameters:
    v - the short

writeChar

      public final void writeChar(int v) throws IOException

  Writes a character.

  Parameters:
    v - the char

writeInt

      public final void writeInt(int v) throws IOException

  Writes an integer.

  Parameters:
    v - the integer

writeLong

      public final void writeLong(long v) throws IOException

  Writes a long.

  Parameters:
    v - the long

writeFloat

      public final void writeFloat(float v) throws IOException

writeDouble

      public final void writeDouble(double v) throws IOException

writeBytes

      public final void writeBytes(String s) throws IOException

  Writes a String as a sequence of bytes.

  Parameters:
    s - the String

writeChars

      public final void writeChars(String s) throws IOException

  Writes a String as a sequence of chars.

  Parameters:
    s - the String

writeUTF

      public final void writeUTF(String str) throws IOException

  Writes a String in UTF format.

  Parameters:
    str - the String

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