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Class java.io.RandomAccessFile

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

public class RandomAccessFile

extends Object

implements DataOutput, DataInput

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.

  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.

  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

  public final FileDescriptor getFD() throws IOException

Returns the opaque file descriptor object.

Returns:

the file descriptor.

  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.

  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.

  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.

  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.

  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.

  public int skipBytes(int n) throws IOException

  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.

  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.

  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.

  public long getFilePointer() throws IOException

Returns the current location of the file pointer.

  public void seek(long pos) throws IOException

Sets the file pointer to the specified absolute position.

Parameters:

pos - the absolute position

  public long length() throws IOException

Returns the length of the file.

  public void close() throws IOException

Closes the file.

Throws: IOException

If an I/O error has occurred.

  public final boolean readBoolean() throws IOException

Reads a boolean.

  public final byte readByte() throws IOException

Reads a byte.

  public final int readUnsignedByte() throws IOException

Reads an unsigned 8 bit byte.

Returns:

the 8 bit byte read.

  public final short readShort() throws IOException

Reads 16 bit short.

Returns:

the read 16 bit short.

  public final int readUnsignedShort() throws IOException

Reads 16 bit short.

Returns:

the read 16 bit short.

  public final char readChar() throws IOException

Reads a 16 bit char.

Returns:

the read 16 bit char.

  public final int readInt() throws IOException

Reads a 32 bit int.

Returns:

the read 32 bit integer.

  public final long readLong() throws IOException

Reads a 64 bit long.

Returns:

the read 64 bit long.

  public final float readFloat() throws IOException

Reads a 32 bit float.

Returns:

the read 32 bit float.

  public final double readDouble() throws IOException

Reads a 64 bit double.

Returns:

the read 64 bit double.

  public final String readLine() throws IOException

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

  public final String readUTF() throws IOException

Reads a UTF formatted String.

  public final void writeBoolean(boolean v) throws IOException

Writes a boolean.

Parameters:

v - the boolean value

  public final void writeByte(int v) throws IOException

Writes a byte.

Parameters:

v - the byte

  public final void writeShort(int v) throws IOException

Writes a short.

Parameters:

v - the short

  public final void writeChar(int v) throws IOException

Writes a character.

Parameters:

v - the char

  public final void writeInt(int v) throws IOException

Writes an integer.

Parameters:

v - the integer

  public final void writeLong(long v) throws IOException

Writes a long.

Parameters:

v - the long

  public final void writeFloat(float v) throws IOException

  public final void writeDouble(double v) throws IOException

  public final void writeBytes(String s) throws IOException

Writes a String as a sequence of bytes.

Parameters:

s - the String

  public final void writeChars(String s) throws IOException

Writes a String as a sequence of chars.

Parameters:

s - the String

  public final void writeUTF(String str) throws IOException

Writes a String in UTF format.

Parameters:

str - the String

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