randomaccessfile.java

gcc的组建

  /**
   * This method reads a Java <code>char</code> value from an input stream.  
   * It operates by reading two bytes from the stream and converting them to 
   * a single 16-bit Java <code>char</code>  The two bytes are stored most
   * significant byte first (i.e., "big endian") regardless of the native
   * host byte ordering. 
   * <p>
   * As an example, if <code>byte1</code> and <code>byte2</code> represent 
   * the first
   * and second byte read from the stream respectively, they will be
   * transformed to a <code>char</code> in the following manner:
   * <p>
   * <code>(char)(((byte1 &amp; 0xFF) &lt;&lt; 8) | (byte2 &amp; 0xFF)</code>
   * <p>
   * This method can read a <code>char</code> written by an object 
   * implementing the
   * <code>writeChar()</code> method in the <code>DataOutput</code> interface.
   *
   * @return The <code>char</code> value read 
   *
   * @exception EOFException If end of file is reached before reading the char
   * @exception IOException If any other error occurs
   *
   * @see DataOutput
   */
  public final char readChar () throws IOException
  {
    return in.readChar();
  }

  /**
   * This method reads a Java double value from an input stream.  It operates
   * by first reading a <code>logn</code> value from the stream by calling the
   * <code>readLong()</code> method in this interface, then 
   * converts that <code>long</code>
   * to a <code>double</code> using the <code>longBitsToDouble</code> 
   * method in the class <code>java.lang.Double</code>
   * <p>
   * This method can read a <code>double</code> written by an object 
   * implementing the
   * <code>writeDouble()</code> method in the <code>DataOutput</code> 
   * interface.
   *
   * @return The <code>double</code> value read
   *
   * @exception EOFException If end of file is reached before reading 
   * the double
   * @exception IOException If any other error occurs
   *
   * @see java.lang.Double
   * @see DataOutput
   */
  public final double readDouble () throws IOException
  {
    return in.readDouble ();
  }

  /**
   * This method reads a Java float value from an input stream.  It operates
   * by first reading an <code>int</code> value from the stream by calling the
   * <code>readInt()</code> method in this interface, then converts 
   * that <code>int</code>
   * to a <code>float</code> using the <code>intBitsToFloat</code> method in 
   * the class <code>java.lang.Float</code>
   * <p>
   * This method can read a <code>float</code> written by an object 
   * implementing the
   * <code>writeFloat()</code> method in the <code>DataOutput</code> interface.
   *
   * @return The <code>float</code> value read
   *
   * @exception EOFException If end of file is reached before reading the float
   * @exception IOException If any other error occurs
   *
   * @see java.lang.Float
   * @see DataOutput
   */
  public final float readFloat () throws IOException
  {
    return in.readFloat();
  }

  /**
   * This method reads raw bytes into the passed array until the array is
   * full.  Note that this method blocks until the data is available and
   * throws an exception if there is not enough data left in the stream to
   * fill the buffer
   *
   * @param buffer The buffer into which to read the data
   *
   * @exception EOFException If end of file is reached before filling the 
   * buffer
   * @exception IOException If any other error occurs
   */
  public final void readFully (byte[] buffer) throws IOException
  {
    in.readFully(buffer);
  }

  /**
   * This method reads raw bytes into the passed array <code>buf</code> 
   * starting
   * <code>offset</code> bytes into the buffer.  The number of bytes read 
   * will be
   * exactly <code>len</code>  Note that this method blocks until the data is 
   * available and throws an exception if there is not enough data left in 
   * the stream to read <code>len</code> bytes.
   *
   * @param buffer The buffer into which to read the data
   * @param offset The offset into the buffer to start storing data
   * @param count The number of bytes to read into the buffer
   *
   * @exception EOFException If end of file is reached before filling 
   * the buffer
   * @exception IOException If any other error occurs
   */
  public final void readFully (byte[] buffer, int offset, int count)
    throws IOException
  {
    in.readFully (buffer, offset, count);
  }

  /**
   * This method reads a Java <code>int</code> value from an input stream
   * It operates by reading four bytes from the stream and converting them to 
   * a single Java <code>int</code>  The bytes are stored most
   * significant byte first (i.e., "big endian") regardless of the native
   * host byte ordering. 
   * <p>
   * As an example, if <code>byte1</code> through <code>byte4</code> 
   * represent the first
   * four bytes read from the stream, they will be
   * transformed to an <code>int</code> in the following manner:
   * <p>
   * <code>(int)(((byte1 &amp; 0xFF) &lt;&lt; 24) + ((byte2 &amp; 0xFF) &lt;&lt; 16) + 
   * ((byte3 &amp; 0xFF) &lt;&lt; 8) + (byte4 &amp; 0xFF)))</code>
   * <p>
   * The value returned is in the range of 0 to 65535.
   * <p>
   * This method can read an <code>int</code> written by an object 
   * implementing the
   * <code>writeInt()</code> method in the <code>DataOutput</code> interface.
   *
   * @return The <code>int</code> value read
   *
   * @exception EOFException If end of file is reached before reading the int
   * @exception IOException If any other error occurs
   *
   * @see DataOutput
   */
  public final int readInt () throws IOException
  {
    return in.readInt();
  }

  /**
   * This method reads the next line of text data from an input stream.
   * It operates by reading bytes and converting those bytes to 
   * <code>char</code>
   * values by treating the byte read as the low eight bits of the 
   * <code>char</code>
   * and using <code>0</code> as the high eight bits.  Because of this, it does
   * not support the full 16-bit Unicode character set.
   * <p>
   * The reading of bytes ends when either the end of file or a line terminator
   * is encountered.  The bytes read are then returned as a <code>String</code>
   * A line terminator is a byte sequence consisting of either 
   * <code>\r</code> <code>\n</code> or <code>\r\n</code>  These 
   * termination charaters are
   * discarded and are not returned as part of the string.
   * <p>
   * This method can read data that was written by an object implementing the
   * <code>writeLine()</code> method in <code>DataOutput</code>
   *
   * @return The line read as a <code>String</code>
   *
   * @exception IOException If an error occurs
   *
   * @see DataOutput
   */
  public final String readLine () throws IOException
  {
    return in.readLine ();
  }

  /**
   * This method reads a Java long value from an input stream
   * It operates by reading eight bytes from the stream and converting them to 
   * a single Java <code>long</code>  The bytes are stored most
   * significant byte first (i.e., "big endian") regardless of the native
   * host byte ordering. 
   * <p>
   * As an example, if <code>byte1</code> through <code>byte8</code> 
   * represent the first
   * eight bytes read from the stream, they will be
   * transformed to an <code>long</code> in the following manner:
   * <p>
   * <code>
   * (long)((((long)byte1 &amp; 0xFF) &lt;&lt; 56) + (((long)byte2 &amp; 0xFF) &lt;&lt; 48) + 
   * (((long)byte3 &amp; 0xFF) &lt;&lt; 40) + (((long)byte4 &amp; 0xFF) &lt;&lt; 32) + 
   * (((long)byte5 &amp; 0xFF) &lt;&lt; 24) + (((long)byte6 &amp; 0xFF) &lt;&lt; 16) + 
   * (((long)byte7 &amp; 0xFF) &lt;&lt; 8) + ((long)byte9 &amp; 0xFF)))</code>
   * <p>
   * The value returned is in the range of 0 to 65535.
   * <p>
   * This method can read an <code>long</code> written by an object 
   * implementing the
   * <code>writeLong()</code> method in the <code>DataOutput</code> interface.
   *
   * @return The <code>long</code> value read
   *
   * @exception EOFException If end of file is reached before reading the long
   * @exception IOException If any other error occurs
   *
   * @see DataOutput
   */
  public final long readLong () throws IOException
  {
    return in.readLong();
  }

  /**
   * This method reads a signed 16-bit value into a Java in from the stream.
   * It operates by reading two bytes from the stream and converting them to 
   * a single 16-bit Java <code>short</code>  The two bytes are stored most
   * significant byte first (i.e., "big endian") regardless of the native
   * host byte ordering. 
   * <p>
   * As an example, if <code>byte1</code> and <code>byte2</code> 
   * represent the first
   * and second byte read from the stream respectively, they will be
   * transformed to a <code>short</code> in the following manner:
   * <p>
   * <code>(short)(((byte1 &amp; 0xFF) &lt;&lt; 8) | (byte2 &amp; 0xFF)</code>
   * <p>
   * The value returned is in the range of -32768 to 32767.
   * <p>
   * This method can read a <code>short</code> written by an object 
   * implementing the
   * <code>writeShort()</code> method in the <code>DataOutput</code> interface.
   *
   * @return The <code>short</code> value read
   *
   * @exception EOFException If end of file is reached before reading the value
   * @exception IOException If any other error occurs
   *
   * @see DataOutput
   */
  public final short readShort () throws IOException
  {
    return in.readShort();
  }

  /**
   * This method reads 8 unsigned bits into a Java <code>int</code> value 
   * from the 
   * stream. The value returned is in the range of 0 to 255.
   * <p>
   * This method can read an unsigned byte written by an object implementing 
   * the <code>writeUnsignedByte()</code> method in the 
   * <code>DataOutput</code> interface.
   *
   * @return The unsigned bytes value read as a Java <code>int</code>
   *
   * @exception EOFException If end of file is reached before reading the value
   * @exception IOException If any other error occurs
   *
   * @see DataOutput
   */
  public final int readUnsignedByte () throws IOException
  {
    return in.readUnsignedByte();
  }

  /**
   * This method reads 16 unsigned bits into a Java int value from the stream.
   * It operates by reading two bytes from the stream and converting them to 
   * a single Java <code>int</code>  The two bytes are stored most
   * significant byte first (i.e., "big endian") regardless of the native
   * host byte ordering. 
   * <p>
   * As an example, if <code>byte1</code> and <code>byte2</code> 
   * represent the first
   * and second byte read from the stream respectively, they will be
   * transformed to an <code>int</code> in the following manner:
   * <p>
   * <code>(int)(((byte1 &amp; 0xFF) &lt;&lt; 8) + (byte2 &amp; 0xFF))</code>
   * <p>
   * The value returned is in the range of 0 to 65535.
   * <p>
   * This method can read an unsigned short written by an object implementing
   * the <code>writeUnsignedShort()</code> method in the 
   * <code>DataOutput</code> interface.
   *
   * @return The unsigned short value read as a Java <code>int</code>
   *
   * @exception EOFException If end of file is reached before reading the value
   * @exception IOException If any other error occurs
   */
  public final int readUnsignedShort () throws IOException
  {
    return in.readUnsignedShort();
  }

  /**
   * This method reads a <code>String</code> from an input stream that 
   * is encoded in
   * a modified UTF-8 format.  This format has a leading two byte sequence
   * that contains the remaining number of bytes to read.  This two byte
   * sequence is read using the <code>readUnsignedShort()</code> method of this
   * interface.
   * <p>
   * After the number of remaining bytes have been determined, these bytes
   * are read an transformed into <code>char</code> values.  
   * These <code>char</code> values
   * are encoded in the stream using either a one, two, or three byte format.
   * The particular format in use can be determined by examining the first
   * byte read.  
   * <p>
   * If the first byte has a high order bit of 0 then
   * that character consists on only one byte.  This character value consists
   * of seven bits that are at positions 0 through 6 of the byte.  As an
   * example, if <code>byte1</code> is the byte read from the stream, it would
   * be converted to a <code>char</code> like so:
   * <p>
   * <code>(char)byte1</code>
   * <p>
   * If the first byte has <code>110</code> as its high order bits, then the 
   * character consists of two bytes.  The bits that make up the character
   * value are in positions 0 through 4 of the first byte and bit positions