public class DataOutputStream extends FilterOutputStream implements DataOutput
A data output stream lets an application write primitive Java data types to an output stream in a portable way. An application can then use a data input stream to read the data back in.
DataInputStream
protected int written
The number of bytes written to the data output stream so far. If this counter overflows, it will be wrapped to Integer.MAX_VALUE.
public DataOutputStream(OutputStream out)
Creates a new data output stream to write data to the specified underlying output stream. The counter written
is set to zero.
out
- the underlying output stream, to be saved for later use.FilterOutputStream.out
public void write(int b) throws IOException
Writes the specified byte (the low eight bits of the argument b
) to the underlying output stream. If no exception is thrown, the counter written
is incremented by 1
.
Implements the write
method of OutputStream
.
write
in interface DataOutput
write
in class FilterOutputStream
b
- the byte
to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public void write(byte[] b, int off, int len) throws IOException
Writes len
bytes from the specified byte array starting at offset off
to the underlying output stream. If no exception is thrown, the counter written
is incremented by len
.
write
in interface DataOutput
write
in class FilterOutputStream
b
- the data.off
- the start offset in the data.len
- the number of bytes to write.IOException
- if an I/O error occurs.FilterOutputStream.out
public void flush() throws IOException
Flushes this data output stream. This forces any buffered output bytes to be written out to the stream.
The flush
method of DataOutputStream
calls the flush
method of its underlying output stream.
flush
in interface Flushable
flush
in class FilterOutputStream
IOException
- if an I/O error occurs.FilterOutputStream.out
, OutputStream.flush()
public final void writeBoolean(boolean v) throws IOException
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
.
writeBoolean
in interface DataOutput
v
- a boolean
value to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public final void writeByte(int v) throws IOException
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
.
writeByte
in interface DataOutput
v
- a byte
value to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public final void writeShort(int v) throws IOException
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
.
writeShort
in interface DataOutput
v
- a short
to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public final void writeChar(int v) throws IOException
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
.
writeChar
in interface DataOutput
v
- a char
value to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public final void writeInt(int v) throws IOException
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
.
writeInt
in interface DataOutput
v
- an int
to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public final void writeLong(long v) throws IOException
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
.
writeLong
in interface DataOutput
v
- a long
to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public final void writeFloat(float v) throws IOException
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
.
writeFloat
in interface DataOutput
v
- a float
value to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
, Float.floatToIntBits(float)
public final void writeDouble(double v) throws IOException
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
.
writeDouble
in interface DataOutput
v
- a double
value to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
, Double.doubleToLongBits(double)
public final void writeBytes(String s) throws IOException
Writes out the string to the underlying output stream as a sequence of bytes. Each character in the string is written out, in sequence, by discarding its high eight bits. If no exception is thrown, the counter written
is incremented by the length of s
.
writeBytes
in interface DataOutput
s
- a string of bytes to be written.IOException
- if an I/O error occurs.FilterOutputStream.out
public final void writeChars(String s) throws IOException
Writes a string to the underlying output stream as a sequence of characters. Each character is written to the data output stream as if by the writeChar
method. If no exception is thrown, the counter written
is incremented by twice the length of s
.
writeChars
in interface DataOutput
s
- a String
value to be written.IOException
- if an I/O error occurs.writeChar(int)
, FilterOutputStream.out
public final void writeUTF(String str) throws IOException
Writes a string to the underlying output stream using modified UTF-8 encoding in a machine-independent manner.
First, two bytes are written to the output stream as if by the writeShort
method giving the number of bytes to follow. This value is the number of bytes actually written out, not the length of the string. Following the length, each character of the string is output, in sequence, using the modified UTF-8 encoding for the character. If no exception is thrown, the counter written
is incremented by the total number of bytes written to the output stream. This will be at least two plus the length of str
, and at most two plus thrice the length of str
.
writeUTF
in interface DataOutput
str
- a string to be written.IOException
- if an I/O error occurs.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.
written
field.written
© 1993–2017, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.