程序包 java.io

类 DataOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.io.DataOutputStream

所有已实现的接口:

Closeable, DataOutput, Flushable, AutoCloseable

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.

从以下版本开始:

JDK1.0

另请参阅:

DataInputStream

字段概要

字段

限定符和类型	字段	说明
protected int	written	The number of bytes written to the data output stream so far.

从类继承的字段 java.io.FilterOutputStream

out

构造器概要

构造器

构造器	说明
DataOutputStream(OutputStream out)	Creates a new data output stream to write data to the specified underlying output stream.

方法概要

限定符和类型	方法	说明
void	flush()	Flushes this data output stream.
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 the underlying output stream.
void	write(int b)	Writes the specified byte (the low eight bits of the argument b) to the underlying 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)	Writes out the string to the underlying output stream as a sequence of bytes.
void	writeChar(int v)	Writes a char to the underlying output stream as a 2-byte value, high byte first.
void	writeChars(String s)	Writes a string to the underlying output stream as a sequence of characters.
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 str)	Writes a string to the underlying output stream using modified UTF-8 encoding in a machine-independent manner.

从接口继承的方法 java.io.DataOutput

write

从类继承的方法 java.io.FilterOutputStream

close, write

从类继承的方法 java.lang.Object

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

字段详细资料

written

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.

构造器详细资料

DataOutputStream

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.

参数:

out - the underlying output stream, to be saved for later use.

另请参阅:

FilterOutputStream.out

方法详细资料

write

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.

指定者:

write 在接口中 DataOutput

覆盖:

write 在类中 FilterOutputStream

参数:

b - the byte to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

write

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.

指定者:

write 在接口中 DataOutput

覆盖:

write 在类中 FilterOutputStream

参数:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

flush

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.

指定者:

flush 在接口中 Flushable

覆盖:

flush 在类中 FilterOutputStream

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out, OutputStream.flush()

writeBoolean

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.

指定者:

writeBoolean 在接口中 DataOutput

参数:

v - a boolean value to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

writeByte

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.

指定者:

writeByte 在接口中 DataOutput

参数:

v - a byte value to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

writeShort

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.

指定者:

writeShort 在接口中 DataOutput

参数:

v - a short to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

writeChar

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.

指定者:

writeChar 在接口中 DataOutput

参数:

v - a char value to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

writeInt

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.

指定者:

writeInt 在接口中 DataOutput

参数:

v - an int to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

writeLong

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.

指定者:

writeLong 在接口中 DataOutput

参数:

v - a long to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

writeFloat

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.

指定者:

writeFloat 在接口中 DataOutput

参数:

v - a float value to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out, Float.floatToIntBits(float)

writeDouble

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.

指定者:

writeDouble 在接口中 DataOutput

参数:

v - a double value to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out, Double.doubleToLongBits(double)

writeBytes

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.

指定者:

writeBytes 在接口中 DataOutput

参数:

s - a string of bytes to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

FilterOutputStream.out

writeChars

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.

指定者:

writeChars 在接口中 DataOutput

参数:

s - a String value to be written.

抛出:

IOException - if an I/O error occurs.

另请参阅:

writeChar(int), FilterOutputStream.out

writeUTF

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.

指定者:

writeUTF 在接口中 DataOutput

参数:

str - a string to be written.

抛出:

IOException - if an I/O error occurs.

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.

返回:

the value of the written field.

另请参阅:

written