org.apache.commons.io.output

类 ByteArrayOutputStream

java.lang.Object

java.io.OutputStream

org.apache.commons.io.output.ByteArrayOutputStream

所有已实现的接口:

Closeable, Flushable, AutoCloseable

public class ByteArrayOutputStream
extends OutputStream

This class implements an output stream in which the data is written into a byte array. The buffer automatically grows as data is written to it.

The data can be retrieved using toByteArray() and toString().

Closing a ByteArrayOutputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

This is an alternative implementation of the ByteArrayOutputStream class. The original implementation only allocates 32 bytes at the beginning. As this class is designed for heavy duty it starts at 1024 bytes. In contrast to the original it doesn't reallocate the whole memory block but allocates additional buffers. This way no buffers need to be garbage collected and the contents don't have to be copied to the new buffer. This class is designed to behave exactly like the original. The only exception is the deprecated toString(int) method that has been ignored.

构造器概要

构造器

构造器和说明
ByteArrayOutputStream() Creates a new byte array output stream.
ByteArrayOutputStream(int size) Creates a new byte array output stream, with a buffer capacity of the specified size, in bytes.

方法概要

限定符和类型	方法和说明
void	close() Closing a ByteArrayOutputStream has no effect.
void	reset()
int	size() Return the current size of the byte array.
static InputStream	toBufferedInputStream(InputStream input) Fetches entire contents of an InputStream and represent same data as result InputStream.
static InputStream	toBufferedInputStream(InputStream input, int size) Fetches entire contents of an InputStream and represent same data as result InputStream.
byte[]	toByteArray() Gets the curent contents of this byte stream as a byte array.
InputStream	toInputStream() Gets the current contents of this byte stream as a Input Stream.
String	toString() 已过时。 2.5 use toString(String) instead
String	toString(Charset charset) Gets the curent contents of this byte stream as a string using the specified encoding.
String	toString(String enc) Gets the curent contents of this byte stream as a string using the specified encoding.
void	write(byte[] b, int off, int len) Write the bytes to byte array.
int	write(InputStream in) Writes the entire contents of the specified input stream to this byte stream.
void	write(int b) Write a byte to byte array.
void	writeTo(OutputStream out) Writes the entire contents of this byte stream to the specified output stream.

从类继承的方法 java.io.OutputStream

flush, write

从类继承的方法 java.lang.Object

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

构造器详细资料

ByteArrayOutputStream

public ByteArrayOutputStream()

Creates a new byte array output stream. The buffer capacity is initially 1024 bytes, though its size increases if necessary.

ByteArrayOutputStream

public ByteArrayOutputStream(int size)

Creates a new byte array output stream, with a buffer capacity of the specified size, in bytes.

参数:

size - the initial size

抛出:

IllegalArgumentException - if size is negative

方法详细资料

write

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

Write the bytes to byte array.

覆盖:

write 在类中 OutputStream

参数:

b - the bytes to write

off - The start offset

len - The number of bytes to write

write

public void write(int b)

Write a byte to byte array.

指定者:

write 在类中 OutputStream

参数:

b - the byte to write

write

public int write(InputStream in)
          throws IOException

Writes the entire contents of the specified input stream to this byte stream. Bytes from the input stream are read directly into the internal buffers of this streams.

参数:

in - the input stream to read from

返回:

total number of bytes read from the input stream (and written to this stream)

抛出:

IOException - if an I/O error occurs while reading the input stream

从以下版本开始:

1.4

size

public int size()

Return the current size of the byte array.

返回:

the current size of the byte array

close

public void close()
           throws IOException

Closing a ByteArrayOutputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

指定者:

close 在接口中 Closeable

指定者:

close 在接口中 AutoCloseable

覆盖:

close 在类中 OutputStream

抛出:

IOException - never (this method should not declare this exception but it has to now due to backwards compatibility)

reset

public void reset()

另请参阅:

ByteArrayOutputStream.reset()

writeTo

public void writeTo(OutputStream out)
             throws IOException

Writes the entire contents of this byte stream to the specified output stream.

参数:

out - the output stream to write to

抛出:

IOException - if an I/O error occurs, such as if the stream is closed

另请参阅:

ByteArrayOutputStream.writeTo(OutputStream)

toBufferedInputStream

public static InputStream toBufferedInputStream(InputStream input)
                                         throws IOException

Fetches entire contents of an InputStream and represent same data as result InputStream.

This method is useful where,

• Source InputStream is slow.
• It has network resources associated, so we cannot keep it open for long time.
• It has network timeout associated.

It can be used in favor of toByteArray(), since it avoids unnecessary allocation and copy of byte[].
This method buffers the input internally, so there is no need to use a BufferedInputStream.

参数:

input - Stream to be fully buffered.

返回:

A fully buffered stream.

抛出:

IOException - if an I/O error occurs

从以下版本开始:

2.0

toBufferedInputStream

public static InputStream toBufferedInputStream(InputStream input,
                                                int size)
                                         throws IOException

Fetches entire contents of an InputStream and represent same data as result InputStream.

This method is useful where,

• Source InputStream is slow.
• It has network resources associated, so we cannot keep it open for long time.
• It has network timeout associated.

It can be used in favor of toByteArray(), since it avoids unnecessary allocation and copy of byte[].
This method buffers the input internally, so there is no need to use a BufferedInputStream.

参数:

input - Stream to be fully buffered.

size - the initial buffer size

返回:

A fully buffered stream.

抛出:

IOException - if an I/O error occurs

从以下版本开始:

2.5

toInputStream

public InputStream toInputStream()

Gets the current contents of this byte stream as a Input Stream. The returned stream is backed by buffers of this stream, avoiding memory allocation and copy, thus saving space and time.

返回:

the current contents of this output stream.

从以下版本开始:

2.5

另请参阅:

ByteArrayOutputStream.toByteArray(), reset()

toByteArray

public byte[] toByteArray()

Gets the curent contents of this byte stream as a byte array. The result is independent of this stream.

返回:

the current contents of this output stream, as a byte array

另请参阅:

ByteArrayOutputStream.toByteArray()

toString

@Deprecated
public String toString()

已过时。 2.5 use toString(String) instead

Gets the curent contents of this byte stream as a string using the platform default charset.

覆盖:

toString 在类中 Object

返回:

the contents of the byte array as a String

另请参阅:

ByteArrayOutputStream.toString()

toString

public String toString(String enc)
                throws UnsupportedEncodingException

Gets the curent contents of this byte stream as a string using the specified encoding.

参数:

enc - the name of the character encoding

返回:

the string converted from the byte array

抛出:

UnsupportedEncodingException - if the encoding is not supported

另请参阅:

ByteArrayOutputStream.toString(String)

toString

public String toString(Charset charset)

Gets the curent contents of this byte stream as a string using the specified encoding.

参数:

charset - the character encoding

返回:

the string converted from the byte array

从以下版本开始:

2.5

另请参阅:

ByteArrayOutputStream.toString(String)