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public interface DataOutput
DataInput
interface.
DataInput
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public void write(byte[] buf) throws IOException
This method writes the raw byte array passed in to the output stream.
- Parameters:
buf
- The byte array to write
- Throws:
IOException
- If an error occurs
public void write(byte[] buf, int offset, int len) throws IOException
This method writes raw bytes from the passed arraybuf
startingoffset
bytes into the buffer. The number of bytes written will be exactlylen
.
- Parameters:
buf
- The buffer from which to write the dataoffset
- The offset into the buffer to start writing data fromlen
- The number of bytes to write from the buffer to the output stream
- Throws:
IOException
- If any other error occurs
public void write(int value) throws IOException
This method writes an 8-bit value (passed into the method as a Javaint
) to an output stream. The low 8 bits of the passed value are written.
- Parameters:
value
- Thebyte
to write to the output stream
- Throws:
IOException
- If an error occurs
public void writeBoolean(boolean value) throws IOException
This method writes a Java boolean value to an output stream. Ifvalue
istrue
, a byte with the value of 1 will be written, otherwise a byte with the value of 0 will be written. The value written can be read using thereadBoolean
method inDataInput
.
- Parameters:
value
- The boolean value to write
- Throws:
IOException
- If an error occurs
- See Also:
DataInput.readBoolean()
public void writeByte(int value) throws IOException
This method writes a Java byte value to an output stream. The byte to be written will be in the lowest 8 bits of theint
value passed. The value written can be read using thereadByte
orreadUnsignedByte
methods inDataInput
.
- Parameters:
value
- The int value to write
- Throws:
IOException
- If an error occurs
public void writeBytes(String value) throws IOException
This method writes all the bytes in aString
out to the stream. One byte is written for each character in theString
. The high eight bits of each character are discarded, thus this method is inappropriate for completely representing Unicode characters.
- Parameters:
value
- TheString
to write
- Throws:
IOException
- If an error occurs
public void writeChar(int value) throws IOException
This method writes a Java char value to an output stream. The char to be written will be in the lowest 16 bits of theint
value passed. These bytes will be written "big endian". That is, with the high byte written first in the following manner:
byte0 = (byte)((value & 0xFF00) >> 8);
byte1 = (byte)(value & 0x00FF);The value written can be read using the
readChar
method inDataInput
.
- Parameters:
value
- The char value to write
- Throws:
IOException
- If an error occurs
- See Also:
DataInput.readChar()
public void writeChars(String value) throws IOException
This method writes all the characters of aString
to an output stream as an array ofchar
's. Each character is written using the method specified in thewriteChar
method.
- Parameters:
value
- The String to write
- Throws:
IOException
- If an error occurs
- See Also:
writeChar(int)
public void writeDouble(double value) throws IOException
This method writes a Javadouble
value to the stream. This value is written by first calling the methodDouble.doubleToLongBits
to retrieve anlong
representing the floating point number, then writing thislong
value to the stream exactly the same as thewriteLong()
method does. The value written can be read using thereadDouble
method inDataInput
.
- Parameters:
value
- The double value to write
- Throws:
IOException
- If any other error occurs
public void writeFloat(float value) throws IOException
This method writes a Javafloat
value to the stream. This value is written by first calling the methodFloat.floatToIntBits
to retrieve anint
representing the floating point number, then writing thisint
value to the stream exactly the same as thewriteInt()
method does. The value written can be read using thereadFloat
method inDataInput
.
- Parameters:
value
- The float value to write
- Throws:
IOException
- If an error occurs
public void writeInt(int value) throws IOException
This method writes a Java int value to an output stream. The 4 bytes of the passed value will be written "big endian". That is, with the high byte written first in the following manner:
byte0 = (byte)((value & 0xFF000000) >> 24);
byte1 = (byte)((value & 0x00FF0000) >> 16);
byte2 = (byte)((value & 0x0000FF00) >> 8);
byte3 = (byte)(value & 0x000000FF);The value written can be read using the
readInt
method inDataInput
.
- Parameters:
value
- The int value to write
- Throws:
IOException
- If an error occurs
- See Also:
DataInput.readInt()
public void writeLong(long value) throws IOException
This method writes a Java long value to an output stream. The 8 bytes of the passed value will be written "big endian". That is, with the high byte written first in the following manner:
byte0 = (byte)((value & 0xFF00000000000000L) >> 56);
byte1 = (byte)((value & 0x00FF000000000000L) >> 48);
byte2 = (byte)((value & 0x0000FF0000000000L) >> 40);
byte3 = (byte)((value & 0x000000FF00000000L) >> 32);
byte4 = (byte)((value & 0x00000000FF000000L) >> 24);
byte5 = (byte)((value & 0x0000000000FF0000L) >> 16);
byte6 = (byte)((value & 0x000000000000FF00L) >> 8);
byte7 = (byte)(value & 0x00000000000000FFL);The value written can be read using the
readLong
method inDataInput
.
- Parameters:
value
- The long value to write
- Throws:
IOException
- If an error occurs
- See Also:
DataInput.readLong()
public void writeShort(int value) throws IOException
This method writes a Java short value to an output stream. The char to be written will be in the lowest 16 bits of theint
value passed. These bytes will be written "big endian". That is, with the high byte written first in the following manner:
byte0 = (byte)((value & 0xFF00) >> 8);
byte1 = (byte)(value & 0x00FF);The value written can be read using the
readShort
andreadUnsignedShort
methods inDataInput
.
- Parameters:
value
- The int value to write as a 16-bit value
- Throws:
IOException
- If an error occurs
public void writeUTF(String value) throws IOException
This method writes a JavaString
to the stream in a modified UTF-8 format. First, two bytes are written to the stream indicating the number of bytes to follow. This is written in the form of a Javashort
value in the same manner used by thewriteShort
method. Note that this is the number of bytes in the encodedString
not theString
length. Next come the encoded characters. Each character in theString
is encoded as either one, two or three bytes. For characters in the range of\u0001
to\u007F
, one byte is used. The character value goes into bits 0-7 and bit eight is 0. For characters in the range of\u0080
to\u007FF
, two bytes are used. Bits 6-10 of the character value are encoded bits 0-4 of the first byte, with the high bytes having a value of "110". Bits 0-5 of the character value are stored in bits 0-5 of the second byte, with the high bits set to "10". This type of encoding is also done for the null character\u0000
. This eliminates any C style NUL character values in the output. All remaining characters are stored as three bytes. Bits 12-15 of the character value are stored in bits 0-3 of the first byte. The high bits of the first bytes are set to "1110". Bits 6-11 of the character value are stored in bits 0-5 of the second byte. The high bits of the second byte are set to "10". And bits 0-5 of the character value are stored in bits 0-5 of byte three, with the high bits of that byte set to "10". The value written can be read using thereadUTF
method inDataInput
.
- Parameters:
value
- TheString
to write
- Throws:
IOException
- If an error occurs
- See Also:
DataInput.readUTF()