java.io
Class DataOutputStream

java.lang.Object
  java.io.OutputStream
      java.io.FilterOutputStream
          java.io.DataOutputStream

All Implemented Interfaces:

DataOutput

public class DataOutputStream
extends FilterOutputStream
implements DataOutput

Transmits java data types as bytes over an OutputStream.

Author:

Brian Bagnall, Sven Köhler

Field Summary

protected int

written

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

DataOutputStream(OutputStream out)

Method Summary

int	size() Returns the current value of the counter written, the number of bytes written to this data output stream so far.
void	write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to this output stream.
void	write(int b) Writes the specified byte to this output stream.
void	writeBoolean(boolean v) Writes a boolean to the underlying output stream as a 1-byte value.
void	writeByte(int v) Writes out a byte to the underlying output stream as a 1-byte value.
void	writeBytes(String s)
void	writeChar(int v) Writes a char to the underlying output stream as a 2-byte value, high byte first.
void	writeChars(String s)
void	writeDouble(double v) Converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the underlying output stream as an 8-byte quantity, high byte first.
void	writeFloat(float v) Converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the underlying output stream as a 4-byte quantity, high byte first.
void	writeInt(int v) Writes an int to the underlying output stream as four bytes, high byte first.
void	writeLong(long v) Writes a long to the underlying output stream as eight bytes, high byte first.
void	writeShort(int v) Writes a short to the underlying output stream as two bytes, high byte first.
void	writeUTF(String s)

Methods inherited from class java.io.FilterOutputStream

close, flush

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

written

protected int written

Constructor Detail

DataOutputStream

public DataOutputStream(OutputStream out)

Method Detail

size

public final int size()

Returns the current value of the counter written, the number of bytes written to this data output stream so far. If the counter overflows, it will be wrapped to Integer.MAX_VALUE.

Returns:

the value of the written field.

See Also:

written

write

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

Description copied from class: OutputStream

Writes len bytes from the specified byte array starting at offset off to this output stream. The general contract for write(b, off, len) is that some of the bytes in the array b are written to the output stream in order; element b[off] is the first byte written and b[off+len-1] is the last byte written by this operation.

The write method of OutputStream calls the write method of one argument on each of the bytes to be written out. Subclasses are encouraged to override this method and provide a more efficient implementation.

If b is null, a NullPointerException is thrown.

If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown.

Specified by:

write in interface DataOutput

Overrides:

write in class FilterOutputStream

Parameters:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

Throws:

IOException - if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed.

See Also:

FilterOutputStream.out

write

public void write(int b)
           throws IOException

Description copied from class: OutputStream

Writes the specified byte to this output stream. The general contract for write is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

Subclasses of OutputStream must provide an implementation for this method.

Specified by:

write in interface DataOutput

Overrides:

write in class FilterOutputStream

Parameters:

b - the byte.

Throws:

IOException - if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed.

See Also:

FilterOutputStream.out

writeBoolean

public final void writeBoolean(boolean v)
                        throws IOException

Description copied from interface: DataOutput

Writes a boolean to the underlying output stream as a 1-byte value. The value true is written out as the value (byte)1; the value false is written out as the value (byte)0. If no exception is thrown, the counter written is incremented by 1.

Specified by:

writeBoolean in interface DataOutput

Parameters:

v - a boolean value to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out

writeByte

public final void writeByte(int v)
                     throws IOException

Description copied from interface: DataOutput

Writes out a byte to the underlying output stream as a 1-byte value. If no exception is thrown, the counter written is incremented by 1.

Specified by:

writeByte in interface DataOutput

Parameters:

v - a byte value to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out

writeBytes

public final void writeBytes(String s)
                      throws IOException

Specified by:

writeBytes in interface DataOutput

Throws:

IOException

writeChar

public final void writeChar(int v)
                     throws IOException

Description copied from interface: DataOutput

Writes a char to the underlying output stream as a 2-byte value, high byte first. If no exception is thrown, the counter written is incremented by 2.

Specified by:

writeChar in interface DataOutput

Parameters:

v - a char value to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out

writeChars

public final void writeChars(String s)
                      throws IOException

Specified by:

writeChars in interface DataOutput

Throws:

IOException

writeDouble

public final void writeDouble(double v)
                       throws IOException

Description copied from interface: DataOutput

Converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the underlying output stream as an 8-byte quantity, high byte first. If no exception is thrown, the counter written is incremented by 8.

Specified by:

writeDouble in interface DataOutput

Parameters:

v - a double value to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out, Double.doubleToLongBits(double)

writeFloat

public final void writeFloat(float v)
                      throws IOException

Description copied from interface: DataOutput

Converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the underlying output stream as a 4-byte quantity, high byte first. If no exception is thrown, the counter written is incremented by 4.

Specified by:

writeFloat in interface DataOutput

Parameters:

v - a float value to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out, Float.floatToIntBits(float)

writeInt

public final void writeInt(int v)
                    throws IOException

Description copied from interface: DataOutput

Writes an int to the underlying output stream as four bytes, high byte first. If no exception is thrown, the counter written is incremented by 4.

Specified by:

writeInt in interface DataOutput

Parameters:

v - an int to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out

writeLong

public final void writeLong(long v)
                     throws IOException

Description copied from interface: DataOutput

Writes a long to the underlying output stream as eight bytes, high byte first. In no exception is thrown, the counter written is incremented by 8.

Specified by:

writeLong in interface DataOutput

Parameters:

v - a long to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out

writeShort

public final void writeShort(int v)
                      throws IOException

Description copied from interface: DataOutput

Writes a short to the underlying output stream as two bytes, high byte first. If no exception is thrown, the counter written is incremented by 2.

Specified by:

writeShort in interface DataOutput

Parameters:

v - a short to be written.

Throws:

IOException - if an I/O error occurs.

See Also:

FilterOutputStream.out

writeUTF

public final void writeUTF(String s)
                    throws IOException

Specified by:

writeUTF in interface DataOutput

Throws:

IOException