GeezerVison is showing docs.oracle.com — ByteArrayOutputStream (Java SE 24 & JDK 24)
Class ByteArrayOutputStream
- All Implemented Interfaces:
Closeable, Flushable, AutoCloseable
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:
- 1.0
-
Field Summary
Fields
Modifier and Type
Field
Description
protected byte[]
The buffer where data is stored.
protected int
The number of valid bytes in the buffer.
-
Constructor Summary
Constructors
Constructor
Description
Creates a new ByteArrayOutputStream.
Creates a new ByteArrayOutputStream, with a buffer capacity of
the specified size, in bytes.
-
Method Summary
Modifier and Type
Method
Description
void
Closing a ByteArrayOutputStream has no effect.
void
Resets the count field of this ByteArrayOutputStream
to zero, so that all currently accumulated output in the
output stream is discarded.
int
Returns the current size of the buffer.
byte[]
Creates a newly allocated byte array.
Converts the buffer's contents into a string decoding bytes using the
default charset.
Deprecated.
This method does not properly convert bytes into characters.
Converts the buffer's contents into a string by decoding the bytes using
the named charset.
Converts the buffer's contents into a string by decoding the bytes using
the specified charset.
void
write(byte[] b,
int off,
int len)
Writes len bytes from the specified byte array
starting at offset off to this ByteArrayOutputStream.
void
Writes the specified byte to this ByteArrayOutputStream.
void
Writes the complete contents of the specified byte array
to this ByteArrayOutputStream.
void
Writes the complete contents of this ByteArrayOutputStream to
the specified output stream argument, as if by calling the output
stream's write method using out.write(buf, 0, count).
-
Field Details
-
buf
protected byte[] buf
The buffer where data is stored.
-
count
protected int count
The number of valid bytes in the buffer.
-
Constructor Details
-
ByteArrayOutputStream
public ByteArrayOutputStream()
Creates a new ByteArrayOutputStream. The buffer capacity is
initially 32 bytes, though its size increases if necessary.
-
ByteArrayOutputStream
public ByteArrayOutputStream(int size)
Creates a new ByteArrayOutputStream, with a buffer capacity of
the specified size, in bytes.
- Parameters:
size - the initial size.
- Throws:
IllegalArgumentException - if size is negative.
-
Method Details
-
write
public void write(int b)
Writes the specified byte to this ByteArrayOutputStream.
- 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 ByteArrayOutputStream.
- Overrides:
write in class OutputStream
- Parameters:
b - the data.
off - the start offset in the data.
len - the number of bytes to write.
- Throws:
NullPointerException - if b is null.
IndexOutOfBoundsException - if off is negative,
len is negative, or len is greater than
b.length - off
-
writeBytes
public void writeBytes(byte[] b)
Writes the complete contents of the specified byte array
to this ByteArrayOutputStream.
- API Note:
- This method is equivalent to
write(b, 0, b.length).
- Parameters:
b - the data.
- Throws:
NullPointerException - if b is null.
- Since:
- 11
-
writeTo
Writes the complete contents of this ByteArrayOutputStream 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:
NullPointerException - if out is null.
IOException - if an I/O error occurs.
-
reset
public void reset()
Resets the count field of this ByteArrayOutputStream
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:
-
-
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
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:
-
-
toString
Converts the buffer's contents into a string decoding bytes using the
default charset. The length of the new String
is a function of the charset, 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
default charset. 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:
- 1.1
- See Also:
-
-
toString
Converts the buffer's contents into a string by decoding the bytes using
the named charset.
This method is equivalent to #toString(charset) that takes a
charset.
An invocation of this method of the form
ByteArrayOutputStream b;
b.toString("UTF-8")
behaves in exactly the same way as the expression
ByteArrayOutputStream b;
b.toString(StandardCharsets.UTF_8)
- Parameters:
charsetName - the name of a supported
charset
- Returns:
- String decoded from the buffer's contents.
- Throws:
UnsupportedEncodingException - If the named charset is not supported
- Since:
- 1.1
-
toString
Converts the buffer's contents into a string by decoding the bytes using
the specified charset. 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 the charset's default replacement string. The CharsetDecoder class should be used when more control
over the decoding process is required.
- Parameters:
charset - the charset
to be used to decode the bytes
- Returns:
- String decoded from the buffer's contents.
- Since:
- 10
-
toString
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 charsetName) or toString(Charset charset)
method, which takes an encoding-name or charset argument,
or the toString() method, which uses the default charset.
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:
-
-
close
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 AutoCloseable
- Specified by:
close in interface Closeable
- Overrides:
close in class OutputStream
- Throws:
IOException - if an I/O error occurs.
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