Package org.python.util

Class ConsoleInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public abstract class ConsoleInputStream
extends java.io.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.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ConsoleInputStream.EOLPolicy
      Enumeration used to specify whether an end-of-line should be added or replaced at the end of each line read.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int available()
      The number of bytes left unread in the current encoded line.
      void mark​(int readlimit)
      Mark is not supported.
      boolean markSupported()
      Mark is not supported.
      int read()
      Read the next byte of data from the buffered input line.
      int read​(byte[] b, int off, int len)
      Reads up to len bytes of data from this input stream into an array of bytes.
      void reset()
      Mark is not supported.
      long skip​(long n)
      Skip forward n bytes within the current encoded line.

      • Methods inherited from class java.io.FilterInputStream

        close, read

      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Method Detail

      • read

        public int read()
         throws java.io.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 java.io.FilterInputStream
        Throws:
        java.io.IOException

      • read

        public int read​(byte[] b,
                int off,
                int len)
         throws java.io.IOException,
                java.io.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 java.io.FilterInputStream
        Throws:
        java.io.IOException
        java.io.EOFException

      • skip

        public long skip​(long n)
          throws java.io.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 java.io.FilterInputStream
        Throws:
        java.io.IOException

      • available

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

      • mark

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

      • reset

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

      • markSupported

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