java.io
Class DataOutputStream

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

All Implemented Interfaces:

Closeable, DataOutput, Flushable

public class DataOutputStream
extends FilterOutputStream
implements DataOutput

DataOutputStream is a filter class which can write typed data to a Stream. Typically, this stream can be read in by a DataInputStream. Types that can be written include byte, 16-bit short, 32-bit int, 32-bit float, 64-bit long, 64-bit double, byte strings, and UTF Strings.

See Also:

DataInputStream

Field Summary

(package private) static int	MAX_BUF_SIZE
protected int	written The number of bytes written out so far

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

DataOutputStream(OutputStream out)
Constructs a new DataOutputStream on the OutputStream out.

Method Summary

(package private) long	countUTFBytes(String str)
void	flush() Flush this DataOutputStream to ensure all pending data is sent out to the target OutputStream.
int	size() Returns the total number of bytes written to this stream thus far.
void	write(byte[] buffer, int offset, int count) Writes count bytes from the byte array buffer starting at offset index to the OutputStream.
void	write(int oneByte) Writes the specified byte to the OutputStream.
void	writeBoolean(boolean val) Writes a boolean to this output stream.
void	writeByte(int val) Writes a 8-bit byte to this output stream.
void	writeBytes(String str) Writes the low order 8-bit bytes from a String to this output stream.
void	writeChar(int val) Writes the specified 16-bit character to the OutputStream.
void	writeChars(String str) Writes the specified 16-bit characters contained in str to the OutputStream.
void	writeDouble(double val) Writes a 64-bit double to this output stream.
void	writeFloat(float val) Writes a 32-bit float to this output stream.
void	writeInt(int val) Writes a 32-bit int to this output stream.
void	writeLong(long val) Writes a 64-bit long to this output stream.
void	writeShort(int val) Writes the specified 16-bit short to the OutputStream.
void	writeUTF(String str) Writes the specified String out in UTF format.
(package private) void	writeUTFBytes(String str, long count)

Methods inherited from class java.io.FilterOutputStream

close, write

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.io.DataOutput

write

Field Detail

written

protected int written

The number of bytes written out so far

MAX_BUF_SIZE

static final int MAX_BUF_SIZE

See Also:

Constant Field Values

Constructor Detail

DataOutputStream

public DataOutputStream(OutputStream out)

Constructs a new DataOutputStream on the OutputStream out. All writes can now be filtered through this stream. Note that data written by this Stream is not in a human readable format but can be reconstructed by using a DataInputStream on the resulting output.

Parameters:

out - the target OutputStream to filter writes on.

Method Detail

flush

public void flush()
           throws IOException

Flush this DataOutputStream to ensure all pending data is sent out to the target OutputStream. This implementation flushes the target OutputStream.

Specified by:

flush in interface Flushable

Overrides:

flush in class FilterOutputStream

Throws:

IOException - If an error occurs attempting to flush this DataOutputStream.

size

public final int size()

Returns the total number of bytes written to this stream thus far.

Returns:

the number of bytes written to this DataOutputStream.

write

public void write(byte[] buffer,
                  int offset,
                  int count)
           throws IOException

Writes count bytes from the byte array buffer starting at offset index to the OutputStream.

Specified by:

write in interface DataOutput

Overrides:

write in class FilterOutputStream

Parameters:

buffer - the buffer to be written

offset - offset in buffer to get bytes

count - number of bytes in buffer to write

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readFully(byte[]), DataInput.readFully(byte[], int, int)

write

public void write(int oneByte)
           throws IOException

Writes the specified byte to the OutputStream.

Specified by:

write in interface DataOutput

Overrides:

write in class FilterOutputStream

Parameters:

oneByte - the byte to be written

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readByte()

writeBoolean

public final void writeBoolean(boolean val)
                        throws IOException

Writes a boolean to this output stream.

Specified by:

writeBoolean in interface DataOutput

Parameters:

val - the boolean value to write to the OutputStream

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readBoolean()

writeByte

public final void writeByte(int val)
                     throws IOException

Writes a 8-bit byte to this output stream.

Specified by:

writeByte in interface DataOutput

Parameters:

val - the byte value to write to the OutputStream

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readByte(), DataInput.readUnsignedByte()

writeBytes

public final void writeBytes(String str)
                      throws IOException

Writes the low order 8-bit bytes from a String to this output stream.

Specified by:

writeBytes in interface DataOutput

Parameters:

str - the String containing the bytes to write to the OutputStream

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readFully(byte[]), DataInput.readFully(byte[],int,int)

writeChar

public final void writeChar(int val)
                     throws IOException

Writes the specified 16-bit character to the OutputStream. Only the lower 2 bytes are written with the higher of the 2 bytes written first. This represents the Unicode value of val.

Specified by:

writeChar in interface DataOutput

Parameters:

val - the character to be written

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readChar()

writeChars

public final void writeChars(String str)
                      throws IOException

Writes the specified 16-bit characters contained in str to the OutputStream. Only the lower 2 bytes of each character are written with the higher of the 2 bytes written first. This represents the Unicode value of each character in str.

Specified by:

writeChars in interface DataOutput

Parameters:

str - the String whose characters are to be written.

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readChar()

writeDouble

public final void writeDouble(double val)
                       throws IOException

Writes a 64-bit double to this output stream. The resulting output is the 8 bytes resulting from calling Double.doubleToLongBits().

Specified by:

writeDouble in interface DataOutput

Parameters:

val - the double to be written.

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readDouble()

writeFloat

public final void writeFloat(float val)
                      throws IOException

Writes a 32-bit float to this output stream. The resulting output is the 4 bytes resulting from calling Float.floatToIntBits().

Specified by:

writeFloat in interface DataOutput

Parameters:

val - the float to be written.

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readFloat()

writeInt

public final void writeInt(int val)
                    throws IOException

Writes a 32-bit int to this output stream. The resulting output is the 4 bytes, highest order first, of val.

Specified by:

writeInt in interface DataOutput

Parameters:

val - the int to be written.

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readInt()

writeLong

public final void writeLong(long val)
                     throws IOException

Writes a 64-bit long to this output stream. The resulting output is the 8 bytes, highest order first, of val.

Specified by:

writeLong in interface DataOutput

Parameters:

val - the long to be written.

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readLong()

writeShort

public final void writeShort(int val)
                      throws IOException

Writes the specified 16-bit short to the OutputStream. Only the lower 2 bytes are written with the higher of the 2 bytes written first.

Specified by:

writeShort in interface DataOutput

Parameters:

val - the short to be written

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readShort(), DataInput.readUnsignedShort()

writeUTF

public final void writeUTF(String str)
                    throws IOException

Writes the specified String out in UTF format.

Specified by:

writeUTF in interface DataOutput

Parameters:

str - the String to be written in UTF format.

Throws:

IOException - If an error occurs attempting to write to this DataOutputStream.

See Also:

DataInput.readUTF()

countUTFBytes

long countUTFBytes(String str)

writeUTFBytes

void writeUTFBytes(String str,
                   long count)
             throws IOException

Throws:

IOException