org.apache.commons.io.output

Class AbstractByteArrayOutputStream<T extends AbstractByteArrayOutputStream<T>>

java.lang.Object

java.io.OutputStream

org.apache.commons.io.output.AbstractByteArrayOutputStream<T>

Type Parameters:

T - The AbstractByteArrayOutputStream subclass

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

Direct Known Subclasses:

ByteArrayOutputStream, UnsynchronizedByteArrayOutputStream

public abstract class AbstractByteArrayOutputStream<T extends AbstractByteArrayOutputStream<T>>
extends OutputStream

This is the base class for implementing 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 an AbstractByteArrayOutputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

This is the base for 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 ByteArrayOutputStream.toString(int) method that has been ignored.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static interface	AbstractByteArrayOutputStream.InputStreamConstructor<T extends InputStream> Constructor for an InputStream subclass.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	count The total count of bytes written.
static int	DEFAULT_SIZE Default buffer size.

Constructor Summary

Constructors

Constructor and Description
AbstractByteArrayOutputStream() Constructs a new instance for subclasses.

Method Summary

Modifier and Type	Method and Description
protected T	asThis() Returns this instance typed to T.
void	close() Does nothing.
protected void	needNewBuffer(int newCount) Makes a new buffer available either by allocating a new one or re-cycling an existing one.
abstract void	reset() See ByteArrayOutputStream.reset().
protected void	resetImpl() Implements a default reset behavior.
abstract int	size() Returns the current size of the byte array.
abstract byte[]	toByteArray() Gets the current contents of this byte stream as a byte array.
protected byte[]	toByteArrayImpl() Gets the current contents of this byte stream as a byte array.
abstract InputStream	toInputStream() Gets the current contents of this byte stream as an Input Stream.
protected <T extends InputStream> InputStream	toInputStream(AbstractByteArrayOutputStream.InputStreamConstructor<T> isConstructor) Gets the current contents of this byte stream as an Input Stream.
String	toString(Charset charset) Gets the current contents of this byte stream as a string using the specified encoding.
String	toString(String enc) Gets the current contents of this byte stream as a string using the specified encoding.
void	write(byte[] b) Writes b.length bytes from the given byte array to this output stream.
abstract void	write(byte[] b, int off, int len)
T	write(CharSequence data, Charset charset) Writes the bytes for given CharSequence encoded using a Charset.
abstract int	write(InputStream in) Writes the entire contents of the specified input stream to this byte stream.
abstract void	write(int b)
protected void	writeImpl(byte[] b, int off, int len) Writes the bytes to the byte array.
protected int	writeImpl(InputStream in) Writes the entire contents of the specified input stream to this byte stream.
protected void	writeImpl(int b) Writes a byte to byte array.
abstract void	writeTo(OutputStream out) Writes the entire contents of this byte stream to the specified output stream.
protected void	writeToImpl(OutputStream out) Writes the entire contents of this byte stream to the specified output stream.

Methods inherited from class java.io.OutputStream

flush

Methods inherited from class java.lang.Object

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

Field Detail

count

protected int count

The total count of bytes written.

DEFAULT_SIZE

public static final int DEFAULT_SIZE

Default buffer size.

See Also:

Constant Field Values

Constructor Detail

AbstractByteArrayOutputStream

public AbstractByteArrayOutputStream()

Constructs a new instance for subclasses.

Method Detail

asThis

protected T asThis()

Returns this instance typed to T.

Returns:

this instance

close

public void close()
           throws IOException

Does nothing. The methods in this class can be called after the stream has been closed without generating an IOException.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

Throws:

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

needNewBuffer

protected void needNewBuffer(int newCount)

Makes a new buffer available either by allocating a new one or re-cycling an existing one.

Parameters:

newCount - the size of the buffer if one is created

reset

public abstract void reset()

See ByteArrayOutputStream.reset().

See Also:

ByteArrayOutputStream.reset()

resetImpl

protected void resetImpl()

Implements a default reset behavior.

See Also:

ByteArrayOutputStream.reset()

size

public abstract int size()

Returns the current size of the byte array.

Returns:

the current size of the byte array

toByteArray

public abstract byte[] toByteArray()

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

Returns:

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

See Also:

ByteArrayOutputStream.toByteArray()

toByteArrayImpl

protected byte[] toByteArrayImpl()

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

Returns:

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

See Also:

ByteArrayOutputStream.toByteArray()

toInputStream

public abstract InputStream toInputStream()

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

Returns:

the current contents of this output stream.

See Also:

ByteArrayOutputStream.toByteArray(), reset()

toInputStream

protected <T extends InputStream> InputStream toInputStream(AbstractByteArrayOutputStream.InputStreamConstructor<T> isConstructor)

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

Type Parameters:

T - the type of the InputStream which makes up the SequenceInputStream.

Parameters:

isConstructor - A constructor for an InputStream which makes up the SequenceInputStream.

Returns:

the current contents of this output stream.

See Also:

ByteArrayOutputStream.toByteArray(), reset()

toString

public String toString(Charset charset)

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

Parameters:

charset - the character encoding

Returns:

the string converted from the byte array

See Also:

ByteArrayOutputStream.toString(String)

toString

public String toString(String enc)
                throws UnsupportedEncodingException

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

Parameters:

enc - the name of the character encoding

Returns:

the string converted from the byte array

Throws:

UnsupportedEncodingException - if the encoding is not supported

See Also:

ByteArrayOutputStream.toString(String)

write

public void write(byte[] b)

Writes b.length bytes from the given byte array to this output stream. This has same effect as write(b, 0, b.length).

Overrides:

write in class OutputStream

Parameters:

b - the data.

See Also:

write(byte[], int, int)

write

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

Overrides:

write in class OutputStream

write

public T write(CharSequence data,
               Charset charset)

Writes the bytes for given CharSequence encoded using a Charset.

Parameters:

data - The String to convert to bytes. not null.

charset - The Charset o encode the String, null means the default encoding.

Returns:

this instance.

write

public abstract 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 buffer of this stream.

Parameters:

in - the input stream to read from

Returns:

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

Throws:

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

write

public abstract void write(int b)

Specified by:

write in class OutputStream

writeImpl

protected void writeImpl(byte[] b,
                         int off,
                         int len)

Writes the bytes to the byte array.

Parameters:

b - the bytes to write

off - The start offset

len - The number of bytes to write

writeImpl

protected int writeImpl(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 buffer of this stream.

Parameters:

in - the input stream to read from

Returns:

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

Throws:

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

writeImpl

protected void writeImpl(int b)

Writes a byte to byte array.

Parameters:

b - the byte to write

writeTo

public abstract void writeTo(OutputStream out)
                      throws IOException

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

Parameters:

out - the output stream to write to

Throws:

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

See Also:

ByteArrayOutputStream.writeTo(OutputStream)

writeToImpl

protected void writeToImpl(OutputStream out)
                    throws IOException

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

Parameters:

out - the output stream to write to

Throws:

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

See Also:

ByteArrayOutputStream.writeTo(OutputStream)