@CleanupObligation public final class WriterOutputStream extends AppendableOutputStream
OutputStream implementation that transforms a byte stream to a
character stream using a specified character set encoding and writes the resulting
stream to a Writer. The stream is transformed using a
CharsetDecoder object, guaranteeing that all character set
encodings supported by the JRE are handled correctly.
The output of the CharsetDecoder is buffered using a fixed size buffer.
This implies that the data is written to the underlying Writer in chunks
that are no larger than the size of this buffer. By default, the buffer is
flushed only when it overflows or when flush() or close()
is called. In general there is therefore no need to wrap the underlying Writer
in a BufferedWriter. WriterOutputStream can also
be instructed to flush the buffer after each write operation. In this case, all
available data is written immediately to the underlying Writer, implying that
the current position of the Writer is correlated to the current position
of the WriterOutputStream.
WriterOutputStream implements the inverse transformation of OutputStreamWriter;
in the following example, writing to out2 would have the same result as writing to
out directly (provided that the byte sequence is legal with respect to the
character set encoding):
OutputStream out = ... Charset cs = ... OutputStreamWriter writer = new OutputStreamWriter(out, cs); WriterOutputStream out2 = new WriterOutputStream(writer, cs);
WriterOutputStream implements the same transformation as InputStreamReader,
except that the control flow is reversed: both classes transform a byte stream
into a character stream, but InputStreamReader pulls data from the underlying stream,
while WriterOutputStream pushes it to the underlying stream.
Note that while there are use cases where there is no alternative to using
this class, very often the need to use this class is an indication of a flaw
in the design of the code. This class is typically used in situations where an existing
API only accepts an OutputStream object, but where the stream is known to represent
character data that must be decoded for further use.
Instances of WriterOutputStream are not thread safe.
ReaderInputStreamdecoderOut| Constructor and Description |
|---|
WriterOutputStream(Writer writer,
Charset charset)
Constructs a new
WriterOutputStream with a default output buffer size of
1024 characters. |
WriterOutputStream(Writer writer,
CharsetDecoder decoder)
Constructs a new
WriterOutputStream with a default output buffer size of
1024 characters. |
WriterOutputStream(Writer writer,
CharsetDecoder decoder,
int bufferSize)
Constructs a new
WriterOutputStream. |
WriterOutputStream(Writer writer,
Charset charset,
int bufferSize)
Constructs a new
WriterOutputStream. |
WriterOutputStream(Writer writer,
String charsetName)
Constructs a new
WriterOutputStream with a default output buffer size of
1024 characters. |
WriterOutputStream(Writer writer,
String charsetName,
int bufferSize)
Constructs a new
WriterOutputStream. |
| Modifier and Type | Method and Description |
|---|---|
void |
close()
Close the stream.
|
void |
flush()
Flush the stream.
|
protected void |
flushOutput()
Flush the output.
|
String |
toString() |
processInput, write, write, writepublic WriterOutputStream(Writer writer, CharsetDecoder decoder)
WriterOutputStream with a default output buffer size of
1024 characters. The output buffer will only be flushed when it overflows or when
flush() or close() is called.writer - the target Writerdecoder - the charset decoderpublic WriterOutputStream(Writer writer, CharsetDecoder decoder, int bufferSize)
WriterOutputStream.writer - the target Writerdecoder - the charset decoderbufferSize - the size of the output buffer in number of characterspublic WriterOutputStream(Writer writer, Charset charset, int bufferSize)
WriterOutputStream.writer - the target Writercharset - the charset encodingbufferSize - the size of the output buffer in number of characterspublic WriterOutputStream(Writer writer, Charset charset)
WriterOutputStream with a default output buffer size of
1024 characters. The output buffer will only be flushed when it overflows or when
flush() or close() is called.writer - the target Writercharset - the charset encodingpublic WriterOutputStream(Writer writer, String charsetName, int bufferSize)
WriterOutputStream.writer - the target WritercharsetName - the name of the charset encodingbufferSize - the size of the output buffer in number of characterspublic WriterOutputStream(Writer writer, String charsetName)
WriterOutputStream with a default output buffer size of
1024 characters. The output buffer will only be flushed when it overflows or when
flush() or close() is called.writer - the target WritercharsetName - the name of the charset encodingpublic void flush()
throws IOException
Writer. After that
Writer.flush() will be called.flush in interface Flushableflush in class AppendableOutputStreamIOException - if an I/O error occurs@DischargesObligation
public void close()
throws IOException
Writer. After that
Writer.close() will be called.close in interface Closeableclose in interface AutoCloseableclose in class AppendableOutputStreamIOException - if an I/O error occursprotected void flushOutput()
throws IOException
flushOutput in class AppendableOutputStreamIOException - if an I/O error occurspublic String toString()
toString in class AppendableOutputStreamCopyright © 2018 SPF4J. All rights reserved.