java.io
Class ByteArrayOutputStream

java.lang.Object
  java.io.OutputStream
      java.io.ByteArrayOutputStream

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.

Since:

JDK1.0

Field Summary

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

Constructor Summary

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.

Method Summary

void	close() Closing a ByteArrayOutputStream has no effect.
void	reset() Resets the count field of this byte array output stream to zero, so that all currently accumulated output in the ouput stream is discarded.
int	size() Returns the current size of the buffer.
byte[]	toByteArray() Creates a newly allocated byte array.
String	toString() Converts the buffer's contents into a string, translating bytes into characters according to the platform's default character encoding.
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 enc) Converts the buffer's contents into a string, translating bytes into characters according to the specified character encoding.
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

ByteArrayOutputStream

public ByteArrayOutputStream()

Creates a new byte array output stream. The buffer capacity is initially 32 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.

Parameters:

size - the initial size.

Throws:

IllegalArgumentException - if size is negative.

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 ouput 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:

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:

count

toString

public String toString()

Converts the buffer's contents into a string, translating bytes into characters according to the platform's default character encoding.

Overrides:

toString in class Object

Returns:

String translated from the buffer's contents.

Since:

JDK1.1

toString

public String toString(String enc)
                throws UnsupportedEncodingException

Converts the buffer's contents into a string, translating bytes into characters according to the specified character encoding.

Parameters:

enc - a character-encoding name.

Returns:

String translated from the buffer's contents.

Throws:

UnsupportedEncodingException - If the named encoding is not supported.

Since:

JDK1.1

toString

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:

size(), toString(String), 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.

Overrides:

close in class OutputStream

Throws:

IOException - if an I/O error occurs.