umich.ms.util

Class ByteArrayHolder

java.lang.Object

java.io.OutputStream

umich.ms.util.ByteArrayHolder

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

public class ByteArrayHolder
extends OutputStream

Auto-growing array of bytes, with access to the underlying data. Almost exactly follows Java's ByteArrayOutputStream, but gives access to underlying data and allows basic navigation.

Author:

Dmitry Avtonomov

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	buf The buffer where data is stored.
protected int	count The number of valid bytes in the buffer.

Constructor Summary

Constructors

Constructor and Description
ByteArrayHolder() Creates a new byte array output stream.
ByteArrayHolder(byte[] underlyingBuf)
ByteArrayHolder(int size) Creates a new byte array output stream, with a buffer capacity of the specified size, in bytes.

Method Summary

Modifier and Type	Method and Description
void	clear()
void	close() Closing a ByteArrayOutputStream has no effect.
void	ensureCapacity(int minCapacity) Increases the capacity if necessary to ensure that it can hold at least the number of elements specified by the minimum capacity argument.
void	ensureCapacity(int minCapacity, boolean keepData)
void	ensureHasSpace(int numBytesToAdd) Checks if there is enough space in the buffer to write N additional bytes.
int	getCapacity()
int	getCapacityLeft()
int	getPosition() This is the position of the next write to the underlying buffer.
byte[]	getUnderlyingBytes()
void	reset() Resets the count field of this byte array output stream to zero, so that all currently accumulated output in the output stream is discarded.
void	setPosition(int newPos) This is a dangerous method, be sure you know what you're doing.
int	size() Returns the current size of the buffer.
byte[]	toByteArray() Creates a newly allocated byte array.
ByteBuffer	toByteBuffer()
String	toString() Converts the buffer's contents into a string decoding bytes using the platform's default character set.
String	toString(int hibyte) Deprecated. This method does not properly convert bytes into characters. As of JDK 1.1, the preferred way to do this is via the toString(String enc) method, which takes an encoding-name argument, or the toString() method, which uses the platform's default character encoding.
String	toString(String charsetName) Converts the buffer's contents into a string by decoding the bytes using the specified charsetName.
void	write(byte[] b, int off, int len) Writes len bytes from the specified byte array starting at offset off to this byte array output stream.
void	write(int b) Writes the specified byte to this byte array output stream.
void	writeTo(OutputStream out) Writes the complete contents of this byte array output stream to the specified output stream argument, as if by calling the output stream's write method using out.write(buf, 0, count).

Methods inherited from class java.io.OutputStream

flush, write

Methods inherited from class java.lang.Object

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

Field Detail

buf

protected byte[] buf

The buffer where data is stored.

count

protected int count

The number of valid bytes in the buffer.

Constructor Detail

ByteArrayHolder

public ByteArrayHolder(int size)

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

Parameters:

size - the initial size.

Throws:

IllegalArgumentException - if size is negative.

ByteArrayHolder

public ByteArrayHolder()

Creates a new byte array output stream. The buffer capacity is initially 32 bytes, though its size increases if necessary.

ByteArrayHolder

public ByteArrayHolder(byte[] underlyingBuf)

Method Detail

write

public void write(int b)

Writes the specified byte to this byte array output stream.

Specified by:

write in class OutputStream

Parameters:

b - the byte to be written.

write

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

Writes len bytes from the specified byte array starting at offset off to this byte array output stream.

Overrides:

write in class OutputStream

Parameters:

b - the data.

off - the start offset in the data.

len - the number of bytes to write.

writeTo

public void writeTo(OutputStream out)
             throws IOException

Writes the complete contents of this byte array output stream to the specified output stream argument, as if by calling the output stream's write method using out.write(buf, 0, count).

Parameters:

out - the output stream to which to write the data.

Throws:

IOException - if an I/O error occurs.

reset

public void reset()

Resets the count field of this byte array output stream to zero, so that all currently accumulated output in the output stream is discarded. The output stream can be used again, reusing the already allocated buffer space.

See Also:

ByteArrayInputStream.count

toByteArray

public byte[] toByteArray()

Creates a newly allocated byte array. Its size is the current size of this output stream and the valid contents of the buffer have been copied into it.

Returns:

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

See Also:

ByteArrayOutputStream.size()

size

public int size()

Returns the current size of the buffer.

Returns:

the value of the count field, which is the number of valid bytes in this output stream.

See Also:

ByteArrayOutputStream.count

toString

public String toString()

Converts the buffer's contents into a string decoding bytes using the platform's default character set. The length of the new String is a function of the character set, and hence may not be equal to the size of the buffer.

This method always replaces malformed-input and unmappable-character sequences with the default replacement string for the platform's default character set. The CharsetDecoder class should be used when more control over the decoding process is required.

Overrides:

toString in class Object

Returns:

String decoded from the buffer's contents.

Since:

JDK1.1

toString

public String toString(String charsetName)
                throws UnsupportedEncodingException

Converts the buffer's contents into a string by decoding the bytes using the specified charsetName. The length of the new String is a function of the charset, and hence may not be equal to the length of the byte array.

This method always replaces malformed-input and unmappable-character sequences with this charset's default replacement string. The CharsetDecoder class should be used when more control over the decoding process is required.

Parameters:

charsetName - the name of a supported Charset charset

Returns:

String decoded from the buffer's contents.

Throws:

UnsupportedEncodingException - If the named charset is not supported

Since:

JDK1.1

toString

@Deprecated
public String toString(int hibyte)

Deprecated. This method does not properly convert bytes into characters. As of JDK 1.1, the preferred way to do this is via the toString(String enc) method, which takes an encoding-name argument, or the toString() method, which uses the platform's default character encoding.

Creates a newly allocated string. Its size is the current size of the output stream and the valid contents of the buffer have been copied into it. Each character c in the resulting string is constructed from the corresponding element b in the byte array such that:

     c == (char)(((hibyte & 0xff) << 8) | (b & 0xff))
 

Parameters:

hibyte - the high byte of each resulting Unicode character.

Returns:

the current contents of the output stream, as a string.

See Also:

ByteArrayOutputStream.size(), ByteArrayOutputStream.toString(String), ByteArrayOutputStream.toString()

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.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class OutputStream

Throws:

IOException

toByteBuffer

public ByteBuffer toByteBuffer()

getUnderlyingBytes

public byte[] getUnderlyingBytes()

getCapacity

public final int getCapacity()

getCapacityLeft

public final int getCapacityLeft()

ensureCapacity

public void ensureCapacity(int minCapacity)

Increases the capacity if necessary to ensure that it can hold at least the number of elements specified by the minimum capacity argument.

Parameters:

minCapacity - the desired minimum capacity

Throws:

OutOfMemoryError - if minCapacity < 0. This is interpreted as a request for the unsatisfiably large capacity (long) Integer.MAX_VALUE + (minCapacity - Integer.MAX_VALUE).

ensureCapacity

public void ensureCapacity(int minCapacity,
                           boolean keepData)

Parameters:

minCapacity - the min capacity to grow the underlying buffer to. The actual increased capacity might be more than that.

keepData - if true, will copy the previous contents of the buffer to the new one. If you are just reusing an old buffer for new data, you might want to set this to false, then the buffer will be reset.

ensureHasSpace

public void ensureHasSpace(int numBytesToAdd)

Checks if there is enough space in the buffer to write N additional bytes. Will grow the buffer if necessary. It takes current position in the buffer into account.

Parameters:

numBytesToAdd - the number of bytes you want to add to the buffer

getPosition

public final int getPosition()

This is the position of the next write to the underlying buffer.

Returns:

the number of valid bytes in the underlying buffer

setPosition

public final void setPosition(int newPos)

This is a dangerous method, be sure you know what you're doing.

clear

public final void clear()