: 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

A data input 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.

Since:: JDK1.0
See Also:: DataInputStream

Field Summary

protected int written
copy-> 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.

Fields inherited from class java.io.FilterOutputStream

out

Constructor Summary

DataOutputStream
copy-> new DataOutputStream( )
copy-> <DataOutputStream var> = new 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.

Parameters:
out - the underlying output stream, to be saved for later use.
See Also:
FilterOutputStream.out

Method Summary

void flush()
copy-> .flush()
copy-> <DataOutputStream>.flush();

Flushes this data output stream. This forces any buffered output bytes to be written out to the stream.
The flush method of DataOuputStream calls the flush method of its underlying output stream.

Overrides:
flush in class FilterOutputStream

Throws:
IOException - if an I/O error occurs.
See Also:
FilterOutputStream.out, OutputStream.flush()

int size()
copy-> .size()
copy-> <int var>=<DataOutputStream>.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

void write(byte[] b, int off, int len)
copy-> .write(, , )
copy-> <DataOutputStream>.write(<byte[] b>, <int off>, <int len>);

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.

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.
See Also:
FilterOutputStream.out

void write(int b)
copy-> .write( )
copy-> <DataOutputStream>.write(<int b>);

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.

Specified by:
write in interface DataOutput
Overrides:
write in class FilterOutputStream

Parameters:
b - the byte to be written.
Throws:
IOException - if an I/O error occurs.
See Also:
FilterOutputStream.out

void writeBoolean(boolean v)
copy-> .writeBoolean( )
copy-> <DataOutputStream>.writeBoolean(<boolean v>);

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

void writeByte(int v)
copy-> .writeByte( )
copy-> <DataOutputStream>.writeByte(<int v>);

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

void writeBytes(String s)
copy-> .writeBytes( )
copy-> <DataOutputStream>.writeBytes(<String s>);

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.

Specified by:
writeBytes in interface DataOutput

Parameters:
s - a string of bytes to be written.
Throws:
IOException - if an I/O error occurs.
See Also:
FilterOutputStream.out

void writeChar(int v)
copy-> .writeChar( )
copy-> <DataOutputStream>.writeChar(<int v>);

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

void writeChars(String s)
copy-> .writeChars( )
copy-> <DataOutputStream>.writeChars(<String s>);

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.

Specified by:
writeChars in interface DataOutput

Parameters:
s - a String value to be written.
Throws:
IOException - if an I/O error occurs.
See Also:
writeChar(int), FilterOutputStream.out

void writeDouble(double v)
copy-> .writeDouble( )
copy-> <DataOutputStream>.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. 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)

void writeFloat(float v)
copy-> .writeFloat( )
copy-> <DataOutputStream>.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. 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)

void writeInt(int v)
copy-> .writeInt( )
copy-> <DataOutputStream>.writeInt(<int v>);

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

void writeLong(long v)
copy-> .writeLong( )
copy-> <DataOutputStream>.writeLong(<long v>);

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

void writeShort(int v)
copy-> .writeShort( )
copy-> <DataOutputStream>.writeShort(<int v>);

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

void writeUTF(String str)
copy-> .writeUTF( )
copy-> <DataOutputStream>.writeUTF(<String str>);

Writes a string to the underlying output stream using 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 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.

Specified by:
writeUTF in interface DataOutput

Parameters:
str - a string to be written.
Throws:
IOException - if an I/O error occurs.

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

Overview

Package

Class

Tree

Deprecated

Index

Help

PREV CLASS NEXT CLASS

Field Summary
`protected int`	written copy-> `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.

Constructor Summary
DataOutputStream copy-> `new DataOutputStream( )` copy-> `<DataOutputStream var> = new 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. Parameters: `out` - the underlying output stream, to be saved for later use. See Also: `FilterOutputStream.out`

Method Summary
`void`	flush() copy-> `.flush()` copy-> `<DataOutputStream>.flush();` Flushes this data output stream. This forces any buffered output bytes to be written out to the stream. The `flush` method of `DataOuputStream` calls the `flush` method of its underlying output stream. Overrides: `flush` in class `FilterOutputStream` Throws: `IOException` - if an I/O error occurs. See Also: `FilterOutputStream.out`, `OutputStream.flush()`
`int`	size() copy-> `.size()` copy-> `<int var>=<DataOutputStream>.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`
`void`	write(byte[] b, int off, int len) copy-> `.write(, , )` copy-> `<DataOutputStream>.write(<byte[] b>, <int off>, <int len>);` 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`. 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. See Also: `FilterOutputStream.out`
`void`	write(int b) copy-> `.write( )` copy-> `<DataOutputStream>.write(<int b>);` 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`. Specified by: `write` in interface `DataOutput` Overrides: `write` in class `FilterOutputStream` Parameters: `b` - the `byte` to be written. Throws: `IOException` - if an I/O error occurs. See Also: `FilterOutputStream.out`
`void`	writeBoolean(boolean v) copy-> `.writeBoolean( )` copy-> `<DataOutputStream>.writeBoolean(<boolean v>);` 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`
`void`	writeByte(int v) copy-> `.writeByte( )` copy-> `<DataOutputStream>.writeByte(<int v>);` 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`
`void`	writeBytes(String s) copy-> `.writeBytes( )` copy-> `<DataOutputStream>.writeBytes(<String s>);` 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`. Specified by: `writeBytes` in interface `DataOutput` Parameters: `s` - a string of bytes to be written. Throws: `IOException` - if an I/O error occurs. See Also: `FilterOutputStream.out`
`void`	writeChar(int v) copy-> `.writeChar( )` copy-> `<DataOutputStream>.writeChar(<int v>);` 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`
`void`	writeChars(String s) copy-> `.writeChars( )` copy-> `<DataOutputStream>.writeChars(<String s>);` 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`. Specified by: `writeChars` in interface `DataOutput` Parameters: `s` - a `String` value to be written. Throws: `IOException` - if an I/O error occurs. See Also: `writeChar(int)`, `FilterOutputStream.out`
`void`	writeDouble(double v) copy-> `.writeDouble( )` copy-> `<DataOutputStream>.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. 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)`
`void`	writeFloat(float v) copy-> `.writeFloat( )` copy-> `<DataOutputStream>.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. 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)`
`void`	writeInt(int v) copy-> `.writeInt( )` copy-> `<DataOutputStream>.writeInt(<int v>);` 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`
`void`	writeLong(long v) copy-> `.writeLong( )` copy-> `<DataOutputStream>.writeLong(<long v>);` 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`
`void`	writeShort(int v) copy-> `.writeShort( )` copy-> `<DataOutputStream>.writeShort(<int v>);` 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`
`void`	writeUTF(String str) copy-> `.writeUTF( )` copy-> `<DataOutputStream>.writeUTF(<String str>);` Writes a string to the underlying output stream using 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 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`. Specified by: `writeUTF` in interface `DataOutput` Parameters: `str` - a string to be written. Throws: `IOException` - if an I/O error occurs.

java.io Class DataOutputStream

java.io
Class DataOutputStream