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Class java.io.InputStreamReader

java.lang.Object
   |
   +----java.io.Reader
           |
           +----java.io.InputStreamReader

public class InputStreamReader

extends Reader

The encoding used by an InputStreamReader may be specified by name, by providing a ByteToCharConverter, or by accepting the default encoding, which is defined by the system property file.encoding.

An InputStreamReader reads bytes from the underlying byte-input stream into an internal buffer. The size of this buffer may be specified, but by default it is large enough for most purposes. Each invocation of a read() method causes the encoding converter to be invoked on the bytes remaining in the buffer. For top efficiency, consider wrapping an InputStreamReader within a BufferedReader so as to avoid frequent converter invocations. For example,

 BufferedReader in
   = new BufferedReader(new InputStreamReader(System.in));
 

See Also:

BufferedReader, InputStream

InputStreamReader(InputStream)

Create an InputStreamReader that uses the default character encoding and the default input-buffer size.

InputStreamReader(InputStream, ByteToCharConverter)

Create an InputStreamReader that uses the specified byte-to-character converter and the default input-buffer size.

InputStreamReader(InputStream, ByteToCharConverter, int)

Create an InputStreamReader that uses the specified byte-to-character converter and the specified input-buffer size.

InputStreamReader(InputStream, int)

Create an InputStreamReader that uses the default character encoding and the specified input-buffer size.

InputStreamReader(InputStream, String)

Create an InputStreamReader that uses the named character encoding and the default input-buffer size.

InputStreamReader(InputStream, String, int)

Create an InputStreamReader that uses the named character encoding and the specified input-buffer size.

close()

Close the stream.

getCharacterEncoding()

Return the name of the encoding being used by this stream.

read()

Read a single character.

read(char[], int, int)

Read characters into a portion of an array.

ready()

Tell whether this stream is ready to be read.

  public InputStreamReader(InputStream in)

Create an InputStreamReader that uses the default character encoding and the default input-buffer size.

Parameters:

in - An InputStream

  public InputStreamReader(InputStream in,
                           String enc) throws UnsupportedEncodingException

Create an InputStreamReader that uses the named character encoding and the default input-buffer size.

Parameters:

in - An InputStream

enc - Name of encoding to be used

Throws: UnsupportedEncodingException

If no converter can be found for the specified encoding

  public InputStreamReader(InputStream in,
                           int sz)

Create an InputStreamReader that uses the default character encoding and the specified input-buffer size.

Parameters:

in - An InputStream

sz - Input-buffer size

Throws: IllegalArgumentException

If sz is <= 0

  public InputStreamReader(InputStream in,
                           String enc,
                           int sz) throws UnsupportedEncodingException

Create an InputStreamReader that uses the named character encoding and the specified input-buffer size.

Parameters:

in - An InputStream

enc - Name of encoding to be used

sz - Input-buffer size

Throws: UnsupportedEncodingException

If no converter can be found for the specified encoding

Throws: IllegalArgumentException

If sz is <= 0

  public InputStreamReader(InputStream in,
                           ByteToCharConverter btc)

Create an InputStreamReader that uses the specified byte-to-character converter and the default input-buffer size. The converter will be reset before its first use. Note: Because the converter has state, it should not be used after the constructor returns.

Parameters:

in - An InputStream

btc - A ByteToCharConverter

  public InputStreamReader(InputStream in,
                           ByteToCharConverter btc,
                           int sz)

Create an InputStreamReader that uses the specified byte-to-character converter and the specified input-buffer size. The converter will be reset before its first use. Note: Because the converter has state, it should not be used after the constructor returns.

Parameters:

in - An InputStream

btc - A ByteToCharConverter

sz - Input-buffer size

Throws: IllegalArgumentException

If sz is <= 0

  public String getCharacterEncoding() throws IOException

Return the name of the encoding being used by this stream.

Throws: IOException

If an I/O error occurs

  public int read() throws IOException

Read a single character. This method is not very efficient, as it invokes the encoding converter once for each character read.

Returns:

The character read, or -1 if the end of the stream has been reached

Throws: IOException

If an I/O error occurs

Overrides:

read in class Reader

See Also:

read

  public int read(char cbuf[],
                  int off,
                  int len) throws IOException

Read characters into a portion of an array.

Parameters:

cbuf - Destination buffer

off - Offset at which to start storing characters

len - Maximum number of characters to read

Returns:

The number of characters read, or -1 if the end of the stream has been reached

Throws: IOException

If an I/O error occurs

Overrides:

read in class Reader

  public boolean ready() throws IOException

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.

Throws: IOException

If an I/O error occurs

Overrides:

ready in class Reader

  public void close() throws IOException

Close the stream.

Throws: IOException

If an I/O error occurs

Overrides:

close in class Reader

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