Interface AbstractDataInput

public int read()
            throws IOException

Read a single byte.

Returns:

a byte, extracted from the stream or -1 if EOF has been reached.

Throws:

IOException -

public int read(byte[] b)
            throws IOException

This method reads bytes from the underlying stream into the specified byte array buffer. It will attempt to fill the buffer completely, but may return a short count if there is insufficient data remaining to be read to fill the buffer.

Parameters:

b - The buffer into which bytes will be read.

Returns:

The actual number of bytes read, or -1 if end of stream reached before reading any bytes.

Throws:

IOException - If an error occurs.

public int read(byte[] b,
                int off,
                int len)
            throws IOException

This method reads bytes from the underlying stream into the specified byte array buffer. It will attempt to read len bytes and will start storing them at position off into the buffer. This method can return a short count if there is insufficient data remaining to be read to complete the desired read length.

Parameters:

b - The buffer into which bytes will be read.

off - The offset into the buffer to start storing bytes.

len - The requested number of bytes to read.

Returns:

The actual number of bytes read, or -1 if end of stream reached before reading any bytes.

Throws:

IOException - If an error occurs.

public boolean readBoolean()
            throws IOException

This method reads a Java boolean value from an input stream. It does so by reading a single byte of data. If that byte is zero, then the value returned is false. If the byte is non-zero, then the value returned is true.

This method can read a boolean written by an object implementing the writeBoolean() method in the DataOutput interface.

Returns:

The boolean value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeBoolean

public byte readByte()
            throws IOException

This method reads a Java byte value from an input stream. The value is in the range of -128 to 127.

This method can read a byte written by an object implementing the writeByte() method in the DataOutput interface.

Returns:

The byte value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeByte

public char readChar()
            throws IOException

This method reads a Java char value from an input stream. It operates by reading two bytes from the stream and converting them to a single 16-bit Java char. The two bytes are stored most significant byte first (i.e., "big endian") regardless of the native host byte ordering.

As an example, if byte1 and byte2 represent the first and second byte read from the stream respectively, they will be transformed to a char in the following manner:

(char)(((byte1 & 0xFF) << 8) | (byte2 & 0xFF)

This method can read a char written by an object implementing the writeChar() method in the DataOutput interface.

Returns:

The char value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeChar

public double readDouble()
            throws IOException

This method reads a Java double value from an input stream. It operates by first reading a long value from the stream by calling the readLong() method in this interface, then converts that long to a double using the longBitsToDouble method in the class java.lang.Double

This method can read a double written by an object implementing the writeDouble() method in the DataOutput interface.

Returns:

The double value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeDouble, Double.longBitsToDouble(long)

public float readFloat()
            throws IOException

This method reads a Java float value from an input stream. It operates by first reading an int value from the stream by calling the readInt() method in this interface, then converts that int to a float using the intBitsToFloat method in the class java.lang.Float

This method can read a float written by an object implementing the writeFloat() method in the DataOutput interface.

Returns:

The float value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeFloat, Float.intBitsToFloat(int)

public void readFully(byte[] b)
            throws IOException

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. Note also that zero length buffers are permitted. In this case, the method will return immediately without reading any bytes from the stream.

Parameters:

b - The buffer into which to read the data

Throws:

IOException - If any other error occurs

public int readInt()
            throws IOException

This method reads a Java int value from an input stream It operates by reading four bytes from the stream and converting them to a single Java int. The bytes are stored most significant byte first (i.e., "big endian") regardless of the native host byte ordering.

As an example, if byte1 through byte4 represent the first four bytes read from the stream, they will be transformed to an int in the following manner:

(int)(((byte1 & 0xFF) << 24) + ((byte2 & 0xFF) << 16) + ((byte3 & 0xFF)<< 8) + (byte4 & 0xFF)))

The value returned is in the range of -2147483648 to 2147483647.

This method can read an int written by an object implementing the writeInt() method in the DataOutput interface.

Returns:

The int value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeInt

public long readLong()
            throws IOException

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 long. The bytes are stored most significant byte first (i.e., "big endian") regardless of the native host byte ordering.

As an example, if byte1 through byte8 represent the first eight bytes read from the stream, they will be transformed to an long in the following manner:

(long)(((byte1 & 0xFF) << 56) + ((byte2 & 0xFF) << 48) + ((byte3 & 0xFF) << 40) + ((byte4 & 0xFF) << 32) + ((byte5 & 0xFF) << 24) + ((byte6 & 0xFF) << 16) + ((byte7 & 0xFF) << 8) + (byte8 & 0xFF)))

The value returned is in the range of -9223372036854775808 to 9223372036854775807.

This method can read an long written by an object implementing the writeLong() method in the DataOutput interface.

Returns:

The long value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeLong

public short readShort()
            throws IOException

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 short. The two bytes are stored most significant byte first (i.e., "big endian") regardless of the native host byte ordering.

As an example, if byte1 and byte2 represent the first and second byte read from the stream respectively, they will be transformed to a short. in the following manner:

(short)(((byte1 & 0xFF) << 8) | (byte2 & 0xFF))

The value returned is in the range of -32768 to 32767.

This method can read a short written by an object implementing the writeShort() method in the DataOutput interface.

Returns:

The short value read

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeShort

public int readUnsignedByte()
            throws IOException

This method reads 8 unsigned bits into a Java int value from the stream. The value returned is in the range of 0 to 255.

This method can read an unsigned byte written by an object implementing the writeUnsignedByte() method in the DataOutput interface.

Returns:

The unsigned bytes value read as a Java int.

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeByte

public int readUnsignedShort()
            throws IOException

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 int The two bytes are stored most significant byte first (i.e., "big endian") regardless of the native host byte ordering.

As an example, if byte1 and byte2 represent the first and second byte read from the stream respectively, they will be transformed to an int in the following manner:

(int)(((byte1 & 0xFF) << 8) + (byte2 & 0xFF))

The value returned is in the range of 0 to 65535.

This method can read an unsigned short written by an object implementing the writeUnsignedShort() method in the DataOutput interface.

Returns:

The unsigned short value read as a Java int

Throws:

IOException - If any other error occurs

See Also:

DataOutput.writeShort

public int skipBytes(int n)
            throws IOException

This method attempts to skip and discard the specified number of bytes in the input stream. It may actually skip fewer bytes than requested. This method will not skip any bytes if passed a negative number of bytes to skip.

Parameters:

n - The requested number of bytes to skip.

Returns:

The requested number of bytes to skip.

Throws:

IOException - If an error occurs.