java.io.DataInput#readChar ( )源码实例Demo

@Override
public void readFields(DataInput in) throws IOException {
	_numRows = in.readInt();
	int numCols = in.readInt();
	int numVals = in.readInt();

	// read col indices
	_colIndexes = new int[numCols];
	for(int i = 0; i < numCols; i++)
		_colIndexes[i] = in.readInt();

	// read distinct values
	_values = new double[numVals * numCols];
	for(int i = 0; i < numVals * numCols; i++)
		_values[i] = in.readDouble();

	// read data
	_data = new char[_numRows];
	for(int i = 0; i < _numRows; i++)
		_data[i] = in.readChar();
}
 

private String readStringFromDataInput(DataInput in) throws IOException {
  byte[] data;
  char firstBytes = in.readChar();

  if (firstBytes == FIRST_MAGIC_BYTES) {
    byte nextByte = in.readByte();
    if (nextByte == NEXT_MAGIC_BYTE) {
      // After those three magic bytes the real input begins
      return readChunks(in);
    } else {
      data = new byte[3];
      data[0] = (byte) (firstBytes >> 8);
      data[1] = (byte) firstBytes;
      data[2] = nextByte;
    }
  } else {
    data = new byte[firstBytes + 2];
    data[0] = (byte) (firstBytes >> 8);
    data[1] = (byte) firstBytes;
    in.readFully(data, 2, firstBytes);
  }

  // In case the read bytes are not from the new input format, back up and
  // return the result readUTF would have returned
  return new DataInputStream(new ByteArrayInputStream(data)).readUTF();
}
 

/**
 * Reads an array of <code>char</code>s from a
 * <code>DataInput</code>.
 *
 * @throws IOException
 *         A problem occurs while reading from <code>in</code>
 *
 * @see #writeCharArray
 * @since 5.7 
 */
public static char[] readCharArray(DataInput in)
  throws IOException {

  InternalDataSerializer.checkIn(in);

  int length = InternalDataSerializer.readArrayLength(in);
  if (length == -1) {
    return null;
  } else {
    char[] array = new char[length];
    for (int i = 0; i < length; i++) {
      array[i] = in.readChar();
    }

    if (DEBUG) {
      InternalDataSerializer.logger.info( LocalizedStrings.DEBUG, "Read char array of length " + length);
    }

    return array;
  }
}
 

@Override
public void readFields(DataInput in) throws IOException {
	_numRows = in.readInt();
	int numCols = in.readInt();
	int numVals = in.readInt();

	// read col indices
	_colIndexes = new int[numCols];
	for(int i = 0; i < numCols; i++)
		_colIndexes[i] = in.readInt();

	// read distinct values
	double[] values = new double[numVals * numCols];
	for(int i = 0; i < numVals * numCols; i++)
		values[i] = in.readDouble();
	_dict = new Dictionary(values);
	
	// read data
	_data = new char[_numRows];
	for(int i = 0; i < _numRows; i++)
		_data[i] = in.readChar();
}
 

@Override
public char[] read(DataInput in) throws IOException {
    final int length = lengthSerializer.read(in);
    final char[] values = new char[length];
    for (int i = 0; i < values.length; i++) {
        values[i] = in.readChar();
    }
    return values;
}
 

@Nullable
public static String readString(@Nonnull final DataInput in) throws IOException {
    final int len = in.readInt();
    if (len == -1) {
        return null;
    }
    final char[] ch = new char[len];
    for (int i = 0; i < len; i++) {
        ch[i] = in.readChar();
    }
    return new String(ch);
}
 

/**
 * Reads a primitive <code>char</code> from a
 * <code>DataInput</code>.
 *
 * @throws IOException
 *         A problem occurs while reading from <code>in</code>
 * @see DataInput#readChar
 * @since 5.1
 */
public static char readPrimitiveChar(DataInput in) throws IOException {
  InternalDataSerializer.checkIn(in);

  char value = in.readChar();
  if (DEBUG) {
    InternalDataSerializer.logger.info( LocalizedStrings.DEBUG, "Read Char " + value);
  }
  return value;
}
 

/**
 * Construct a Row object from input carried in via the given input stream.
 * 
 * @param is the input stream
 * @exception IOException if an I/O error occurs
 */
public Row(DataInput is) throws IOException {
  for (int i = is.readInt(); i > 0; i--) {
    char ch = is.readChar();
    Cell c = new Cell();
    c.cmd = is.readInt();
    c.cnt = is.readInt();
    c.ref = is.readInt();
    c.skip = is.readInt();
    cells.put(ch, c);
  }
}
 

@Nullable
public static String readString(@Nonnull final DataInput in) throws IOException {
    final int len = in.readInt();
    if (len == -1) {
        return null;
    }
    final char[] ch = new char[len];
    for (int i = 0; i < len; i++) {
        ch[i] = in.readChar();
    }
    return new String(ch);
}
 

/**
 * Reads a primitive <code>char</code> from a
 * <code>DataInput</code>.
 *
 * @throws IOException
 *         A problem occurs while reading from <code>in</code>
 * @see DataInput#readChar
 * @since 5.1
 */
public static char readPrimitiveChar(DataInput in) throws IOException {
  InternalDataSerializer.checkIn(in);

  char value = in.readChar();
  if (DEBUG) {
    InternalDataSerializer.logger.info( LocalizedStrings.DEBUG, "Read Char " + value);
  }
  return value;
}
 

public static ResultLob newLob(DataInput dataInput,
                               boolean readTerminate) throws IOException {

    ResultLob result = new ResultLob();

    result.databaseID = dataInput.readInt();
    result.sessionID  = dataInput.readLong();
    result.lobID      = dataInput.readLong();
    result.subType    = dataInput.readInt();

    switch (result.subType) {

        case LobResultTypes.REQUEST_CREATE_BYTES :
        case LobResultTypes.REQUEST_CREATE_CHARS :
            result.blockOffset = dataInput.readLong();
            result.blockLength = dataInput.readLong();
            break;

        case LobResultTypes.REQUEST_GET_LOB :
        case LobResultTypes.REQUEST_DUPLICATE_LOB :

        //
        case LobResultTypes.REQUEST_GET_BYTES :
        case LobResultTypes.REQUEST_GET_CHARS :
            result.blockOffset = dataInput.readLong();
            result.blockLength = dataInput.readLong();
            break;

        case LobResultTypes.REQUEST_SET_BYTES :
        case LobResultTypes.REQUEST_GET_BYTE_PATTERN_POSITION :
            result.blockOffset = dataInput.readLong();
            result.blockLength = dataInput.readLong();
            result.byteBlock   = new byte[(int) result.blockLength];

            dataInput.readFully(result.byteBlock);
            break;

        case LobResultTypes.REQUEST_SET_CHARS :
        case LobResultTypes.REQUEST_GET_CHAR_PATTERN_POSITION :
            result.blockOffset = dataInput.readLong();
            result.blockLength = dataInput.readLong();
            result.charBlock   = new char[(int) result.blockLength];

            for (int i = 0; i < result.charBlock.length; i++) {
                result.charBlock[i] = dataInput.readChar();
            }
            break;

        case LobResultTypes.REQUEST_GET_LENGTH :
        case LobResultTypes.REQUEST_TRUNCATE :
            result.blockOffset = dataInput.readLong();
            break;

        case LobResultTypes.RESPONSE_GET_BYTES :
            result.blockOffset = dataInput.readLong();
            result.blockLength = dataInput.readLong();
            result.byteBlock   = new byte[(int) result.blockLength];

            dataInput.readFully(result.byteBlock);
            break;

        case LobResultTypes.RESPONSE_GET_CHARS :
            result.blockOffset = dataInput.readLong();
            result.blockLength = dataInput.readLong();
            result.charBlock   = new char[(int) result.blockLength];

            for (int i = 0; i < result.charBlock.length; i++) {
                result.charBlock[i] = dataInput.readChar();
            }
            break;

        case LobResultTypes.RESPONSE_SET :
        case LobResultTypes.RESPONSE_CREATE_BYTES :
        case LobResultTypes.RESPONSE_CREATE_CHARS :
        case LobResultTypes.RESPONSE_TRUNCATE :
            result.blockLength = dataInput.readLong();
            break;

        case LobResultTypes.RESPONSE_GET_BYTE_PATTERN_POSITION :
        case LobResultTypes.RESPONSE_GET_CHAR_PATTERN_POSITION :
            result.blockOffset = dataInput.readLong();
            break;

        default :
            throw Error.runtimeError(ErrorCode.U_S0500, "ResultLob");
    }

    if (readTerminate) {
        dataInput.readByte();
    }

    return result;
}
 

/** Read ArithmeticProgression from DataInput */
private static ArithmeticProgression read(DataInput in) throws IOException {
  return new ArithmeticProgression(in.readChar(),
      in.readLong(), in.readLong(), in.readLong());
}
 

private void readCharArray(DataInput in) throws IOException {
  char[] v = (char[]) value;
  for (int i = 0; i < length; i++)
    v[i] = in.readChar(); 
}
 

public static Character readCharacter(DataInput input) throws IOException
{
	return input.readChar();
}
 

@Override
public void read(DataInput in) throws IOException {
	this.value = in.readChar();
}
 

/** Read ArithmeticProgression from DataInput */
private static ArithmeticProgression read(DataInput in) throws IOException {
  return new ArithmeticProgression(in.readChar(),
      in.readLong(), in.readLong(), in.readLong());
}
 

private void readCharArray(DataInput in) throws IOException {
  char[] v = (char[]) value;
  for (int i = 0; i < length; i++)
    v[i] = in.readChar(); 
}
 

public static Character readCharacter(DataInput input) throws IOException
{
	return input.readChar();
}
 

@Override
public Character read(final DataInput in) throws IOException {
    return in.readChar();
}
 

@Override
public void read(DataInput in) throws IOException {
	this.value = in.readChar();
}