BufferedReader JDK 1.6)

Description

public class BufferedReader

Reads text from a character-input stream, buffering characters so as to provide for the efficient reading of characters, arrays, and lines.

The buffer size may be specified, or the default size may be used. The default is large enough for most purposes.

In general, each read request made of a Reader causes a corresponding read request to be made of the underlying character or byte stream. It is therefore advisable to wrap a BufferedReader around any Reader whose read() operations may be costly, such as FileReaders and InputStreamReaders. For example,

 BufferedReader in
   = new BufferedReader(new FileReader("foo.in"));

will buffer the input from the specified file. Without buffering, each invocation of read() or readLine() could cause bytes to be read from the file, converted into characters, and then returned, which can be very inefficient.

Programs that use DataInputStreams for textual input can be localized by replacing each DataInputStream with an appropriate BufferedReader.

See also: FileReader InputStreamReader

Methods

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public void close () throws IOException [Specified in Reader]

public void mark (int readAheadLimit) throws IOException [Overrides Reader]

Marks the present position in the stream.

public boolean markSupported () [Overrides Reader]

Tells whether this stream supports the mark() operation, which it does.

public int read () throws IOException [Overrides Reader]

Reads a single character.

public int read (char[] cbuf) throws IOException [Inherited From Reader]

Reads characters into an array.

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

Reads characters into a portion of an array.

This method implements the general contract of the corresponding read method of the Reader class. As an additional convenience, it attempts to read as many characters as possible by repeatedly invoking the read method of the underlying stream. This iterated read continues until one of the following conditions becomes true:

The specified number of characters have been read,
The read method of the underlying stream returns -1, indicating end-of-file, or
The ready method of the underlying stream returns false, indicating that further input requests would block.

If the first read on the underlying stream returns -1 to indicate end-of-file then this method returns -1. Otherwise this method returns the number of characters actually read.

Subclasses of this class are encouraged, but not required, to attempt to read as many characters as possible in the same fashion.

Ordinarily this method takes characters from this stream's character buffer, filling it from the underlying stream as necessary. If, however, the buffer is empty, the mark is not valid, and the requested length is at least as large as the buffer, then this method will read characters directly from the underlying stream into the given array. Thus redundant BufferedReaders will not copy data unnecessarily.
Returns: The number of characters read, or -1 if the end of the stream has been reached
Parameters:
- cbuf - Destination buffer
- off - Offset at which to start storing characters
- len - Maximum number of characters to read
Throws:
- IOException - If an I/O error occurs

public int read (CharBuffer target) throws IOException [Inherited From Reader]

Attempts to read characters into the specified character buffer.

public String readLine () throws IOException

Reads a line of text.

pack-private String readLine (boolean ignoreLF) throws IOException

Reads a line of text.

public boolean ready () throws IOException [Overrides Reader]

Tells whether this stream is ready to be read.

public void reset () throws IOException [Overrides Reader]

Resets the stream to the most recent mark.

public long skip (long n) throws IOException [Overrides Reader]

Skips characters.

Skips characters.
Returns: The number of characters actually skipped
Parameters:
- n - The number of characters to skip
Throws:
- IllegalArgumentException - If n is negative.
- IOException - If an I/O error occurs