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java.lang.Object | +----java.io.RandomAccessFile
RandomAccessFile(File, String)
File argument.
RandomAccessFile(String, String)
close()
getFD()
getFilePointer()
length()
read()
read(byte[])
b.length bytes of data from this file
into an array of bytes.
read(byte[], int, int)
len bytes of data from this file into an
array of bytes.
readBoolean()
boolean from this file.
readByte()
readChar()
readDouble()
double from this file.
readFloat()
float from this file.
readFully(byte[])
b.length bytes from this file into the byte
array.
readFully(byte[], int, int)
len bytes from this file into the byte
array.
readInt()
readLine()
readLong()
readShort()
readUnsignedByte()
readUnsignedShort()
readUTF()
seek(long)
skipBytes(int)
n bytes of input.
write(byte[])
b.length bytes from the specified byte array
starting at offset off to this file.
write(byte[], int, int)
len bytes from the specified byte array
starting at offset off to this file.
write(int)
writeBoolean(boolean)
boolean to the file as a 1-byte value.
writeByte(int)
byte to the file as a 1-byte value.
writeBytes(String)
writeChar(int)
char to the file as a 2-byte value, high
byte first.
writeChars(String)
writeDouble(double)
long using the
doubleToLongBits method in class Double,
and then writes that long value to the file as an
8-byte quantity, high byte first.
writeFloat(float)
int using the
floatToIntBits method in class Float,
and then writes that int value to the file as a
4-byte quantity, high byte first.
writeInt(int)
int to the file as four bytes, high byte first.
writeLong(long)
long to the file as eight bytes, high byte first.
writeShort(int)
short to the file as two bytes, high byte first.
writeUTF(String)
RandomAccessFile
public RandomAccessFile(String name,
String mode) throws IOException
The mode argument must either be equal to "r" or
"rw", indicating either to open the file for input or
for both input and output.
"r" or to "rw".
checkRead method is called with the name
argument to see if the application is allowed read access
to the file. If the mode argument is equal to
"rw", its checkWrite method also
is called with the name argument to see if the application
is allowed write access to the file. Either of these may
result in a security exception.
RandomAccessFile
public RandomAccessFile(File file,
String mode) throws IOException
File argument.
The mode argument must either be equal to "r" or to
"rw", indicating either to open the file for input,
or for both input and output, respectively.
"r" or to "rw".
checkRead method is called with the pathname
of the File argument to see if the
application is allowed read access to the file. If the
mode argument is equal to "rw", its
checkWrite method also is called with the
pathname to see if the application is allowed write access
to the file.
getFD
public final FileDescriptor getFD() throws IOException
read
public native int read() throws IOException
-1 if the end of the
file is reached.
read
public int read(byte b[],
int off,
int len) throws IOException
len bytes of data from this file into an
array of bytes. This method blocks until at least one byte of input
is available.
-1 if there is no more data because the end of
the file has been reached.
read
public int read(byte b[]) throws IOException
b.length bytes of data from this file
into an array of bytes. This method blocks until at least one byte
of input is available.
-1 if there is no more data because the end of
this file has been reached.
readFully
public final void readFully(byte b[]) throws IOException
b.length bytes from this file into the byte
array. This method reads repeatedly from the file until all the
bytes are read. This method blocks until all the bytes are read,
the end of the stream is detected, or an exception is thrown.
readFully
public final void readFully(byte b[],
int off,
int len) throws IOException
len bytes from this file into the byte
array. This method reads repeatedly from the file until all the
bytes are read. This method blocks until all the bytes are read,
the end of the stream is detected, or an exception is thrown.
skipBytes
public int skipBytes(int n) throws IOException
n bytes of input.
This method blocks until all the bytes are skipped, the end of the stream is detected, or an exception is thrown.
n.
write
public native void write(int b) throws IOException
byte to be written.
write
public void write(byte b[]) throws IOException
b.length bytes from the specified byte array
starting at offset off to this file.
write
public void write(byte b[],
int off,
int len) throws IOException
len bytes from the specified byte array
starting at offset off to this file.
getFilePointer
public native long getFilePointer() throws IOException
seek
public native void seek(long pos) throws IOException
length
public native long length() throws IOException
close
public native void close() throws IOException
readBoolean
public final boolean readBoolean() throws IOException
boolean from this file. This method reads a
single byte from the file. A value of 0 represents
false. Any other value represents true.
This method blocks until the byte is read, the end of the stream
is detected, or an exception is thrown.
boolean value read.
readByte
public final byte readByte() throws IOException
b, where
0 <= b <= 255,
then the result is:
(byte)(b)
This method blocks until the byte is read, the end of the stream is detected, or an exception is thrown.
byte.
readUnsignedByte
public final int readUnsignedByte() throws IOException
This method blocks until the byte is read, the end of the stream is detected, or an exception is thrown.
readShort
public final short readShort() throws IOException
b1 and b2, where each of the two values is
between 0 and 255, inclusive, then the
result is equal to:
(short)((b1 << 8) | b2)
This method blocks until the two bytes are read, the end of the stream is detected, or an exception is thrown.
readUnsignedShort
public final int readUnsignedShort() throws IOException
b1 and b2, where
0 <= b1, b2 <= 255,
then the result is equal to:
(b1 << 8) | b2
This method blocks until the two bytes are read, the end of the stream is detected, or an exception is thrown.
readChar
public final char readChar() throws IOException
b1 and b2, where
0 <= b1, b2 <= 255,
then the result is equal to:
(char)((b1 << 8) | b2)
This method blocks until the two bytes are read, the end of the stream is detected, or an exception is thrown.
readInt
public final int readInt() throws IOException
b1,
b2, b3, and b4, where
0 <= b1, b2, b3, b4 <= 255,
then the result is equal to:
(b1 << 24) | (b2 << 16) + (b3 << 8) + b4
This method blocks until the four bytes are read, the end of the stream is detected, or an exception is thrown.
int.
readLong
public final long readLong() throws IOException
b1, b2, b3,
b4, b5, b6,
b7, and b8, where:
0 <= b1, b2, b3, b4, b5, b6, b7, b8 <=255,
then the result is equal to:
((long)b1 << 56) + ((long)b2 << 48)
+ ((long)b3 << 40) + ((long)b4 << 32)
+ ((long)b5 << 24) + ((long)b6 << 16)
+ ((long)b7 << 8) + b8
This method blocks until the eight bytes are read, the end of the stream is detected, or an exception is thrown.
long.
readFloat
public final float readFloat() throws IOException
float from this file. This method reads an
int value as if by the readInt method
and then converts that int to a float
using the intBitsToFloat method in class
Float.
This method blocks until the four bytes are read, the end of the stream is detected, or an exception is thrown.
float.
readDouble
public final double readDouble() throws IOException
double from this file. This method reads a
long value as if by the readLong method
and then converts that long to a double
using the longBitsToDouble method in
class Double.
This method blocks until the eight bytes are read, the end of the stream is detected, or an exception is thrown.
double.
readLine
public final String readLine() throws IOException
A line of text is terminated by a carriage-return character
('\r'), a newline character ('\n'), a
carriage-return character immediately followed by a newline
character, or the end of the input stream. The line-terminating
character(s), if any, are included as part of the string returned.
This method blocks until a newline character is read, a carriage return and the byte following it are read (to see if it is a newline), the end of the stream is detected, or an exception is thrown.
readUTF
public final String readUTF() throws IOException
The first two bytes are read as if by
readUnsignedShort. This value gives the number of
following bytes that are in the encoded string, not
the length of the resulting string. The following bytes are then
interpreted as bytes encoding characters in the UTF-8 format
and are converted into characters.
This method blocks until all the bytes are read, the end of the stream is detected, or an exception is thrown.
writeBoolean
public final void writeBoolean(boolean v) throws IOException
boolean to the file as a 1-byte value. The
value true is written out as the value
(byte)1; the value false is written out
as the value (byte)0.
boolean value to be written.
writeByte
public final void writeByte(int v) throws IOException
byte to the file as a 1-byte value.
byte value to be written.
writeShort
public final void writeShort(int v) throws IOException
short to the file as two bytes, high byte first.
short to be written.
writeChar
public final void writeChar(int v) throws IOException
char to the file as a 2-byte value, high
byte first.
char value to be written.
writeInt
public final void writeInt(int v) throws IOException
int to the file as four bytes, high byte first.
int to be written.
writeLong
public final void writeLong(long v) throws IOException
long to the file as eight bytes, high byte first.
long to be written.
writeFloat
public final void writeFloat(float v) throws IOException
int using the
floatToIntBits method in class Float,
and then writes that int value to the file as a
4-byte quantity, high byte first.
float value to be written.
writeDouble
public final void writeDouble(double v) throws IOException
long using the
doubleToLongBits method in class Double,
and then writes that long value to the file as an
8-byte quantity, high byte first.
double value to be written.
writeBytes
public final void writeBytes(String s) throws IOException
writeChars
public final void writeChars(String s) throws IOException
writeChar method.
String value to be written.
writeUTF
public final void writeUTF(String str) throws IOException
First, two bytes are written to the file as if by the
writeShort method giving the number of bytes to
follow. This value is the number of bytes actually written out,
not the length of the string. Following the length, each character
of the string is output, in sequence, using the UTF-8 encoding
for each character.
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