TelnetInputStream

Class Overview

This class provides input and output streams for telnet clients. This class overrides read to do CRLF processing as specified in RFC 854. The class assumes it is running on a system where lines are terminated with a single newline character. This is the relevant section of RFC 824 regarding CRLF processing:

 The sequence "CR LF", as defined, will cause the NVT to be
 positioned at the left margin of the next print line (as would,
 for example, the sequence "LF CR").  However, many systems and
 terminals do not treat CR and LF independently, and will have to
 go to some effort to simulate their effect.  (For example, some
 terminals do not have a CR independent of the LF, but on such
 terminals it may be possible to simulate a CR by backspacing.)
 Therefore, the sequence "CR LF" must be treated as a single "new
 line" character and used whenever their combined action is
 intended; the sequence "CR NUL" must be used where a carriage
 return alone is actually desired; and the CR character must be
 avoided in other contexts.  This rule gives assurance to systems
 which must decide whether to perform a "new line" function or a
 multiple-backspace that the TELNET stream contains a character
 following a CR that will allow a rational decision.

    Note that "CR LF" or "CR NUL" is required in both directions
    (in the default ASCII mode), to preserve the symmetry of the
    NVT model.  Even though it may be known in some situations
    (e.g., with remote echo and suppress go ahead options in
    effect) that characters are not being sent to an actual
    printer, nonetheless, for the sake of consistency, the protocol
    requires that a NUL be inserted following a CR not followed by
    a LF in the data stream.  The converse of this is that a NUL
    received in the data stream after a CR (in the absence of
    options negotiations which explicitly specify otherwise) should
    be stripped out prior to applying the NVT to local character
    set mapping.
 

Summary

[Expand] Inherited Fields
From class java.io.FilterInputStream protected InputStream in The input stream to be filtered.

[Expand] Inherited Methods
From class java.io.FilterInputStream int available() Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream. void close() Closes this input stream and releases any system resources associated with the stream. synchronized void mark(int readlimit) Marks the current position in this input stream. boolean markSupported() Tests if this input stream supports the mark and reset methods. int read(byte[] b) Reads up to byte.length bytes of data from this input stream into an array of bytes. int read() Reads the next byte of data from this input stream. int read(byte[] b, int off, int len) Reads up to len bytes of data from this input stream into an array of bytes. synchronized void reset() Repositions this stream to the position at the time the mark method was last called on this input stream. long skip(long n) Skips over and discards n bytes of data from this input stream. This method simply performs in.skip(n).
From class java.io.InputStream int available() 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. void close() Closes this input stream and releases any system resources associated with the stream. synchronized void mark(int readlimit) Marks the current position in this input stream. boolean markSupported() Tests if this input stream supports the mark and reset methods. int read(byte[] b) Reads some number of bytes from the input stream and stores them into the buffer array b. abstract int read() Reads the next byte of data from the input stream. int read(byte[] b, int off, int len) Reads up to len bytes of data from the input stream into an array of bytes. synchronized void reset() Repositions this stream to the position at the time the mark method was last called on this input stream. long skip(long n) Skips over and discards n bytes of data from this input stream.
From class java.lang.Object Object clone() Creates and returns a copy of this object. boolean equals(Object obj) Indicates whether some other object is "equal to" this one. void finalize() Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. final Class<?> getClass() Returns the runtime class of this Object. int hashCode() Returns a hash code value for the object. final void notify() Wakes up a single thread that is waiting on this object's monitor. final void notifyAll() Wakes up all threads that are waiting on this object's monitor. String toString() Returns a string representation of the object. final void wait() Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object. final void wait(long timeout, int nanos) Causes the current thread to wait until another thread invokes the notify() method or the notifyAll() method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed. final void wait(long timeout) Causes the current thread to wait until either another thread invokes the notify() method or the notifyAll() method for this object, or a specified amount of time has elapsed.
From interface java.io.Closeable abstract void close() Closes this stream and releases any system resources associated with it.