public class PushbackInputStream extends FilterInputStream

A PushbackInputStream adds functionality to another input stream, namely the ability to "push back" or "unread" one byte. This is useful in situations where it is convenient for a fragment of code to read an indefinite number of data bytes that are delimited by a particular byte value; after reading the terminating byte, the code fragment can "unread" it, so that the next read operation on the input stream will reread the byte that was pushed back. For example, bytes representing the characters constituting an identifier might be terminated by a byte representing an operator character; a method whose job is to read just an identifier can read until it sees the operator and then push the operator back to be re-read.

Field Summary

protected byte[] buf The pushback buffer.
protected int pos The position within the pushback buffer from which the next byte will be read.

Inherited Field Summary

Public Constructor Summary

PushbackInputStream(InputStream in, int size)
Creates a PushbackInputStream with a pushback buffer of the specified size, and saves its argument, the input stream in, for later use.
PushbackInputStream(InputStream in)
Creates a PushbackInputStream and saves its argument, the input stream in, for later use.

Public Method Summary

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.
synchronized void
Closes this input stream and releases any system resources associated with the stream.
synchronized void