Package org.python.util

Class ConsoleInputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
org.python.util.ConsoleInputStream
All Implemented Interfaces:
Closeable, AutoCloseable
public abstract class ConsoleInputStream extends FilterInputStream
This class is intended to replace System.in for use with console libraries that provide a line-oriented input mechanism. The console libraries provide a method to get the next line from the console as a String. Particular sub-classes should wrap this character-oriented method in a definition of getLine().

The libraries JLine and Java Readline have both been used to give Jython line-recall, editing and a line history preserved between sessions. Both deal with the console encoding internally, and interact with the user in terms of a buffer of characters. Our need in Jython is to access a byte-stream encoding the characters, with line-endings, since it is the text layer of the Python io stack, whether we are using the io module or file built-in, that should deal with encoding.

  • Method Details

    • read

      public int read() throws IOException
      Read the next byte of data from the buffered input line. The byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been recognised, the value -1 is returned. This method blocks until input data are available, the end of the stream is detected, or an exception is thrown. Normally, an empty line results in an encoded end-of-line being returned.
      Overrides:
      read in class FilterInputStream
      Throws:
      IOException

    • read

      public int read(byte[] b, int off, int len) throws IOException, EOFException
      Reads up to len bytes of data from this input stream into an array of bytes. If len is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0 is returned. This implementation calls getLine() at most once to get a line of characters from the console, and encodes them as bytes to be read back from the stream.
      Overrides:
      read in class FilterInputStream
      Throws:
      IOException
      EOFException

    • skip

      public long skip(long n) throws IOException
      Skip forward n bytes within the current encoded line. A call to skip will not result in reading a new line with getLine().
      Overrides:
      skip in class FilterInputStream
      Throws:
      IOException

    • available

      public int available() throws IOException
      The number of bytes left unread in the current encoded line.
      Overrides:
      available in class FilterInputStream
      Throws:
      IOException

    • mark

      public void mark(int readlimit)
      Mark is not supported.
      Overrides:
      mark in class FilterInputStream

    • reset

      public void reset() throws IOException
      Mark is not supported.
      Overrides:
      reset in class FilterInputStream
      Throws:
      IOException

    • markSupported

      public boolean markSupported()
      Mark is not supported.
      Overrides:
      markSupported in class FilterInputStream