InputStreamReaderpublic class InputStreamReader extends Reader An InputStreamReader is a bridge from byte streams to character streams: It
reads bytes and decodes them into characters using a specified {@link
java.nio.charset.Charset charset}. The charset that it uses
may be specified by name or may be given explicitly, or the platform's
default charset may be accepted.
Each invocation of one of an InputStreamReader's read() methods may
cause one or more bytes to be read from the underlying byte-input stream.
To enable the efficient conversion of bytes to characters, more bytes may
be read ahead from the underlying stream than are necessary to satisfy the
current read operation.
For top efficiency, consider wrapping an InputStreamReader within a
BufferedReader. For example:
BufferedReader in
= new BufferedReader(new InputStreamReader(System.in));
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| Fields Summary |
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| private final StreamDecoder | sd |
| Constructors Summary |
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public InputStreamReader(InputStream in)Create an InputStreamReader that uses the default charset.
super(in);
try {
sd = StreamDecoder.forInputStreamReader(in, this, (String)null); // ## check lock object
} catch (UnsupportedEncodingException e) {
// The default encoding should always be available
throw new Error(e);
}
| public InputStreamReader(InputStream in, String charsetName)Create an InputStreamReader that uses the named charset.
super(in);
if (charsetName == null)
throw new NullPointerException("charsetName");
sd = StreamDecoder.forInputStreamReader(in, this, charsetName);
| public InputStreamReader(InputStream in, Charset cs)Create an InputStreamReader that uses the given charset.
super(in);
if (cs == null)
throw new NullPointerException("charset");
sd = StreamDecoder.forInputStreamReader(in, this, cs);
| public InputStreamReader(InputStream in, CharsetDecoder dec)Create an InputStreamReader that uses the given charset decoder.
super(in);
if (dec == null)
throw new NullPointerException("charset decoder");
sd = StreamDecoder.forInputStreamReader(in, this, dec);
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| Methods Summary |
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| public void | close()Close the stream.
sd.close();
| | public java.lang.String | getEncoding()Return the name of the character encoding being used by this stream.
If the encoding has an historical name then that name is returned;
otherwise the encoding's canonical name is returned.
If this instance was created with the {@link
#InputStreamReader(InputStream, String)} constructor then the returned
name, being unique for the encoding, may differ from the name passed to
the constructor. This method may return null if the stream
has been closed.
return sd.getEncoding();
| | public int | read()Read a single character.
return sd.read();
| | public int | read(char[] cbuf, int offset, int length)Read characters into a portion of an array.
return sd.read(cbuf, offset, length);
| | public boolean | ready()Tell whether this stream is ready to be read. An InputStreamReader is
ready if its input buffer is not empty, or if bytes are available to be
read from the underlying byte stream.
return sd.ready();
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