Package org.python.util

Class ConsoleOutputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable
    public class ConsoleOutputStream
extends java.io.FilterOutputStream
    This class may be used to wrap and replace System.out so that the console handling library (JLine or Java Readline) can treat an incomplete line (one without a newline) as a prompt string, and so know the true position of the cursor. It achieves this by keeping a copy of bytes that pass through from from upstream to the true System.out, until either a newline arrives, or a defined capacity (typically the console width) is reached. If client code requests the partial line as a prompt, that action also empties the buffer. In that case, the client (which is the console object) is responsible for making the prompt emerge on the real console.

    • Constructor Summary

      Constructors 
      Constructor Description
      ConsoleOutputStream​(java.io.OutputStream out, int promptCapacity)
      Create a wrapper on an OutputStream that holds a copy of the last incomplete line written to it (as bytes), in case it is needed as a console prompt.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()  
      void flush()  
      void write​(int b)
      This write method steals a copy of each byte in a buffer while passing it on to the wrapped stream.

      • Methods inherited from class java.io.FilterOutputStream

        write, write

      • Methods inherited from class java.io.OutputStream

        nullOutputStream

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • ConsoleOutputStream

        public ConsoleOutputStream​(java.io.OutputStream out,
                           int promptCapacity)
        Create a wrapper on an OutputStream that holds a copy of the last incomplete line written to it (as bytes), in case it is needed as a console prompt.
        Parameters:
        out - the stream wrapped (normally System.out)
        promptCapacity - maximum number of bytes to buffer

    • Method Detail

      • write

        public void write​(int b)
           throws java.io.IOException
        This write method steals a copy of each byte in a buffer while passing it on to the wrapped stream. The buffer is reset by each newline, when it overflows, or by the client when it is taken as a console prompt in getPrompt(Charset).
        Overrides:
        write in class java.io.FilterOutputStream
        Throws:
        java.io.IOException

      • flush

        public void flush()
           throws java.io.IOException
        Specified by:
        flush in interface java.io.Flushable
        Overrides:
        flush in class java.io.FilterOutputStream
        Throws:
        java.io.IOException

      • close

        public void close()
           throws java.io.IOException
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class java.io.FilterOutputStream
        Throws:
        java.io.IOException