randomaccessfile.java

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    }

    /**
     * Reads a signed 64-bit integer from this file. This method reads eight
     * bytes from the file, starting at the current file pointer. 
     * If the bytes read, in order, are 
     * <code>b1</code>, <code>b2</code>, <code>b3</code>, 
     * <code>b4</code>, <code>b5</code>, <code>b6</code>, 
     * <code>b7</code>, and <code>b8,</code> where:
     * <blockquote><pre>
     *     0 &lt;= b1, b2, b3, b4, b5, b6, b7, b8 &lt;=255,
     * </pre></blockquote>
     * <p>
     * then the result is equal to:
     * <p><blockquote><pre>
     *     ((long)b1 &lt;&lt; 56) + ((long)b2 &lt;&lt; 48)
     *     + ((long)b3 &lt;&lt; 40) + ((long)b4 &lt;&lt; 32)
     *     + ((long)b5 &lt;&lt; 24) + ((long)b6 &lt;&lt; 16)
     *     + ((long)b7 &lt;&lt; 8) + b8
     * </pre></blockquote>
     * <p>
     * This method blocks until the eight bytes are read, the end of the 
     * stream is detected, or an exception is thrown. 
     *
     * @return     the next eight bytes of this file, interpreted as a
     *             <code>long</code>.
     * @exception  EOFException  if this file reaches the end before reading
     *               eight bytes.
     * @exception  IOException   if an I/O error occurs.
     */
    public final long readLong() throws IOException {
	return ((long)(readInt()) << 32) + (readInt() & 0xFFFFFFFFL);
    }

    /**
     * Reads a <code>float</code> from this file. This method reads an 
     * <code>int</code> value, starting at the current file pointer, 
     * as if by the <code>readInt</code> method 
     * and then converts that <code>int</code> to a <code>float</code> 
     * using the <code>intBitsToFloat</code> method in class 
     * <code>Float</code>. 
     * <p>
     * This method blocks until the four bytes are read, the end of the 
     * stream is detected, or an exception is thrown. 
     *
     * @return     the next four bytes of this file, interpreted as a
     *             <code>float</code>.
     * @exception  EOFException  if this file reaches the end before reading
     *             four bytes.
     * @exception  IOException   if an I/O error occurs.
     * @see        java.io.RandomAccessFile#readInt()
     * @see        java.lang.Float#intBitsToFloat(int)
     */
    public final float readFloat() throws IOException {
	return Float.intBitsToFloat(readInt());
    }

    /**
     * Reads a <code>double</code> from this file. This method reads a 
     * <code>long</code> value, starting at the current file pointer, 
     * as if by the <code>readLong</code> method 
     * and then converts that <code>long</code> to a <code>double</code> 
     * using the <code>longBitsToDouble</code> method in 
     * class <code>Double</code>.
     * <p>
     * This method blocks until the eight bytes are read, the end of the 
     * stream is detected, or an exception is thrown. 
     *
     * @return     the next eight bytes of this file, interpreted as a
     *             <code>double</code>.
     * @exception  EOFException  if this file reaches the end before reading
     *             eight bytes.
     * @exception  IOException   if an I/O error occurs.
     * @see        java.io.RandomAccessFile#readLong()
     * @see        java.lang.Double#longBitsToDouble(long)
     */
    public final double readDouble() throws IOException {
	return Double.longBitsToDouble(readLong());
    }

    /**
     * Reads the next line of text from this file.  This method successively
     * reads bytes from the file, starting at the current file pointer, 
     * until it reaches a line terminator or the end
     * of the file.  Each byte is converted into a character by taking the
     * byte's value for the lower eight bits of the character and setting the
     * high eight bits of the character to zero.  This method does not,
     * therefore, support the full Unicode character set.
     *
     * <p> A line of text is terminated by a carriage-return character
     * (<code>'&#92;r'</code>), a newline character (<code>'&#92;n'</code>), a
     * carriage-return character immediately followed by a newline character,
     * or the end of the file.  Line-terminating characters are discarded and
     * are not included as part of the string returned.
     *
     * <p> 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 file is reached, or an exception is thrown.
     *
     * @return     the next line of text from this file, or null if end
     *             of file is encountered before even one byte is read.
     * @exception  IOException  if an I/O error occurs.
     */

    public final String readLine() throws IOException {
	StringBuffer input = new StringBuffer();
	int c = -1;
	boolean eol = false;

	while (!eol) {
	    switch (c = read()) {
	    case -1:
	    case '\n':
		eol = true;
		break;
	    case '\r':
		eol = true;
		long cur = getFilePointer();
		if ((read()) != '\n') {
		    seek(cur);
		}
		break;
	    default:
		input.append((char)c);
		break;
	    }
	}

	if ((c == -1) && (input.length() == 0)) {
	    return null;
	}
	return input.toString();
    }

    /**
     * Reads in a string from this file. The string has been encoded 
     * using a modified UTF-8 format. 
     * <p>
     * The first two bytes are read, starting from the current file 
     * pointer, as if by 
     * <code>readUnsignedShort</code>. 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. 
     * <p>
     * This method blocks until all the bytes are read, the end of the 
     * stream is detected, or an exception is thrown. 
     *
     * @return     a Unicode string.
     * @exception  EOFException            if this file reaches the end before
     *               reading all the bytes.
     * @exception  IOException             if an I/O error occurs.
     * @exception  UTFDataFormatException  if the bytes do not represent 
     *               valid UTF-8 encoding of a Unicode string.
     * @see        java.io.RandomAccessFile#readUnsignedShort()
     */
    public final String readUTF() throws IOException {
	return DataInputStream.readUTF(this);
    }

    /**
     * Writes a <code>boolean</code> to the file as a one-byte value. The 
     * value <code>true</code> is written out as the value 
     * <code>(byte)1</code>; the value <code>false</code> is written out 
     * as the value <code>(byte)0</code>. The write starts at 
     * the current position of the file pointer.
     *
     * @param      v   a <code>boolean</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeBoolean(boolean v) throws IOException {
	write(v ? 1 : 0);
	//written++;
    }

    /**
     * Writes a <code>byte</code> to the file as a one-byte value. The 
     * write starts at the current position of the file pointer.
     *
     * @param      v   a <code>byte</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeByte(int v) throws IOException {
	write(v);
	//written++;
    }

    /**
     * Writes a <code>short</code> to the file as two bytes, high byte first. 
     * The write starts at the current position of the file pointer.
     *
     * @param      v   a <code>short</code> to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeShort(int v) throws IOException {
	write((v >>> 8) & 0xFF);
	write((v >>> 0) & 0xFF);
	//written += 2;
    }

    /**
     * Writes a <code>char</code> to the file as a two-byte value, high
     * byte first. The write starts at the current position of the 
     * file pointer.
     *
     * @param      v   a <code>char</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeChar(int v) throws IOException {
	write((v >>> 8) & 0xFF);
	write((v >>> 0) & 0xFF);
	//written += 2;
    }

    /**
     * Writes an <code>int</code> to the file as four bytes, high byte first. 
     * The write starts at the current position of the file pointer.
     *
     * @param      v   an <code>int</code> to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeInt(int v) throws IOException {
	write((v >>> 24) & 0xFF);
	write((v >>> 16) & 0xFF);
	write((v >>>  8) & 0xFF);
	write((v >>>  0) & 0xFF);
	//written += 4;
    }

    /**
     * Writes a <code>long</code> to the file as eight bytes, high byte first. 
     * The write starts at the current position of the file pointer.
     *
     * @param      v   a <code>long</code> to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeLong(long v) throws IOException {
	write((int)(v >>> 56) & 0xFF);
	write((int)(v >>> 48) & 0xFF);
	write((int)(v >>> 40) & 0xFF);
	write((int)(v >>> 32) & 0xFF);
	write((int)(v >>> 24) & 0xFF);
	write((int)(v >>> 16) & 0xFF);
	write((int)(v >>>  8) & 0xFF);
	write((int)(v >>>  0) & 0xFF);
	//written += 8;
    }

    /**
     * Converts the float argument to an <code>int</code> using the 
     * <code>floatToIntBits</code> method in class <code>Float</code>, 
     * and then writes that <code>int</code> value to the file as a 
     * four-byte quantity, high byte first. The write starts at the 
     * current position of the file pointer.
     *
     * @param      v   a <code>float</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.lang.Float#floatToIntBits(float)
     */
    public final void writeFloat(float v) throws IOException {
	writeInt(Float.floatToIntBits(v));
    }

    /**
     * Converts the double argument to a <code>long</code> using the 
     * <code>doubleToLongBits</code> method in class <code>Double</code>, 
     * and then writes that <code>long</code> value to the file as an 
     * eight-byte quantity, high byte first. The write starts at the current 
     * position of the file pointer.
     *
     * @param      v   a <code>double</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.lang.Double#doubleToLongBits(double)
     */
    public final void writeDouble(double v) throws IOException {
	writeLong(Double.doubleToLongBits(v));
    }

    /**
     * Writes the string to the file as a sequence of bytes. Each 
     * character in the string is written out, in sequence, by discarding 
     * its high eight bits. The write starts at the current position of 
     * the file pointer.
     *
     * @param      s   a string of bytes to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeBytes(String s) throws IOException {
	int len = s.length();

	char[] val = new char[len];
	s.getChars(0, len, val, 0);

	byte[] b = new byte[len];

        for (int i = 0; i < len; ++i) {
            b[i] = (byte)val[i];
        }

	writeBytes(b, 0, len);

    }

    /**
     * Writes a string to the file as a sequence of characters. Each 
     * character is written to the data output stream as if by the 
     * <code>writeChar</code> method. The write starts at the current 
     * position of the file pointer.
     *
     * @param      s   a <code>String</code> value to be written.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.RandomAccessFile#writeChar(int)
     */
    public final void writeChars(String s) throws IOException {
	int clen = s.length();
	int blen = 2*clen;
	byte[] b = new byte[blen];
	char[] c = new char[clen];
	s.getChars(0, clen, c, 0);
	for (int i = 0, j = 0; i < clen; i++) {
	    b[j++] = (byte)(c[i] >>> 8);
	    b[j++] = (byte)(c[i] >>> 0);
	}
	writeBytes(b, 0, blen);
    }

    /**
     * Writes a string to the file using UTF-8 encoding in a 
     * machine-independent manner. 
     * <p>
     * First, two bytes are written to the file, starting at the 
     * current file pointer, as if by the 
     * <code>writeShort</code> 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. 
     *
     * @param      str   a string to be written.
     * @exception  IOException  if an I/O error occurs.
     */
    public final void writeUTF(String str) throws IOException {
        DataOutputStream.writeUTF(str, this);
    }

    private static native void initIDs();

    private native void close0() throws IOException;

    static {
	initIDs();
    }

}