Java IO.pdf - Nguyen Dang Binh

public RandomAccessFile(File file, String mode) throws IOException
Java I/O
The first argument to the constructor is the file you want to access. The second argument is
the mode for access. The mode should be either the string literal "r" for read-only access or
the string "rw" for read/write access. Java does not support write-only access. For example:
RandomAccessFile raf = new RandomAccessFile("29.html", "r");
An IllegalArgumentException is thrown if anything other than the strings "rw" or "r" is
passed as the second argument to this constructor. A security exception is thrown if the
security manager does not allow the requested file to be read. A security exception is also
thrown if you request read/write access, but only read access is allowed. Security checks are
made only when the object is constructed. It is assumed that the security manger's policy
won't change while the program is running. Finally, an IOException is thrown if the
operating system doesn't allow the file to be accessed or some other I/O problem occurs.
The getFilePointer() and seek() methods allow you to determine and modify the position
in the file at which reads and writes occur. Attempts to seek (position the file pointer) past the
end of the file just move the file pointer to the end of the file. Attempts to write from the end
of the file extend the file.
public native long getFilePointer() throws IOException
public native void seek(long pos) throws IOException
Attempts to read from the end of the file throw an EOFException (a subclass of
IOException). You can determine the length of the file with the length() method:
public native long length() throws IOException
The RandomAccessFile class implements both the DataInput and DataOutput interfaces.
Therefore, reads and writes use methods exactly like the methods of the DataInputStream
and DataOutputStream classes, such as read(), readFully(), readBoolean(),
writeBoolean(), and so on.
public native int read() throws IOException
public int read(byte[] data, int offset, int length) throws IOException
public int read(byte[] data) throws IOException
public final void readFully(byte[] data) throws IOException
public final void readFully(byte[] data, int offset, int length)
throws IOException
public native void write(int b) throws IOException
public void write(byte[] data) throws IOException
public void write(byte[] data, int offset, int length) throws IOException
public final boolean readBoolean() throws IOException
public final byte readByte() throws IOException
public final int readUnsignedByte() throws IOException
public final short readShort() throws IOException
public final int readUnsignedShort() throws IOException
public final char readChar() throws IOException
public final int readInt() throws IOException
public final long readLong() throws IOException
public final float readFloat() throws IOException
public final double readDouble() throws IOException
public final String readLine() throws IOException
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