Class ByteArrayOutputStream
- java.lang.Object
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- java.io.OutputStream
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- java.io.ByteArrayOutputStream
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- All Implemented Interfaces:
- 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 usingtoByteArray()
andtoString()
.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
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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.
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Constructor Summary
Constructors Constructor and Description 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.
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method and Description void
close()
Closing a ByteArrayOutputStream has no effect.void
reset()
Resets thecount
field of this byte array output stream to zero, so that all currently accumulated output in the output 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 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 thetoString(String enc)
method, which takes an encoding-name argument, or thetoString()
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 namedcharset
.void
write(byte[] b, int off, int len)
Writeslen
bytes from the specified byte array starting at offsetoff
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 usingout.write(buf, 0, count)
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Methods inherited from class java.io.OutputStream
flush, write
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Field Detail
buf
protected byte[] buf
The buffer where data is stored.
count
protected int count
The number of valid bytes in the buffer.
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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:
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IllegalArgumentException
- if size is negative.
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Method Detail
write
public void write(int b)
Writes the specified byte to this byte array output stream.- Specified by:
-
write
in classOutputStream
- Parameters:
-
b
- the byte to be written.
write
public void write(byte[] b, int off, int len)
Writeslen
bytes from the specified byte array starting at offsetoff
to this byte array output stream.- Overrides:
-
write
in classOutputStream
- 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 usingout.write(buf, 0, count)
.- Parameters:
-
out
- the output stream to which to write the data. - Throws:
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IOException
- if an I/O error occurs.
reset
public void reset()
Resets thecount
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:
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size()
size
public int size()
Returns the current size of the buffer.- Returns:
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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 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.
toString
public String toString(String charsetName) throws UnsupportedEncodingException
Converts the buffer's contents into a string by decoding the bytes using the namedcharset
. 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 supportedcharset
- Returns:
- String decoded from the buffer's contents.
- Throws:
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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 thetoString(String enc)
method, which takes an encoding-name argument, or thetoString()
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:
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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.- Specified by:
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close
in interfaceCloseable
- Specified by:
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close
in interfaceAutoCloseable
- Overrides:
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close
in classOutputStream
- Throws:
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IOException
- if an I/O error occurs.
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