Class ExternalTerminal

  • All Implemented Interfaces:
    java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable, TerminalExt, Terminal

    public class ExternalTerminal
    extends LineDisciplineTerminal
    Terminal implementation designed for external connections with embedded line discipline.

    The ExternalTerminal class provides a terminal implementation that is well-suited for supporting incoming external connections, such as those from network sources (telnet, SSH, or other protocols). It extends the LineDisciplineTerminal class, inheriting its line discipline functionality while adding features specific to external connection handling.

    This terminal implementation starts consuming input in a separate thread to generate interruption events promptly, ensuring that signals like Ctrl+C are processed immediately rather than waiting for the application to read the input. This is particularly important for network-based terminals where latency could otherwise affect the responsiveness of signal handling.

    Key features of this implementation include:

    • Support for external connections over various protocols
    • Prompt signal handling through background input processing
    • Configurable terminal type and attributes
    • Support for dynamic size changes

    This terminal is commonly used in server applications that need to provide terminal access to remote clients, such as SSH servers, telnet servers, or custom network protocols that require terminal emulation.

    See Also:
    LineDisciplineTerminal
    • Field Detail

      • closed

        protected final java.util.concurrent.atomic.AtomicBoolean closed
      • masterInput

        protected final java.io.InputStream masterInput
      • lock

        protected final java.lang.Object lock
      • paused

        protected boolean paused
      • pumpThread

        protected java.lang.Thread pumpThread
    • Constructor Detail

      • ExternalTerminal

        public ExternalTerminal​(java.lang.String name,
                                java.lang.String type,
                                java.io.InputStream masterInput,
                                java.io.OutputStream masterOutput,
                                java.nio.charset.Charset encoding)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • ExternalTerminal

        public ExternalTerminal​(TerminalProvider provider,
                                java.lang.String name,
                                java.lang.String type,
                                java.io.InputStream masterInput,
                                java.io.OutputStream masterOutput,
                                java.nio.charset.Charset encoding,
                                Terminal.SignalHandler signalHandler)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • ExternalTerminal

        public ExternalTerminal​(TerminalProvider provider,
                                java.lang.String name,
                                java.lang.String type,
                                java.io.InputStream masterInput,
                                java.io.OutputStream masterOutput,
                                java.nio.charset.Charset encoding,
                                java.nio.charset.Charset stdinEncoding,
                                java.nio.charset.Charset stdoutEncoding,
                                java.nio.charset.Charset stderrEncoding,
                                Terminal.SignalHandler signalHandler)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • ExternalTerminal

        public ExternalTerminal​(TerminalProvider provider,
                                java.lang.String name,
                                java.lang.String type,
                                java.io.InputStream masterInput,
                                java.io.OutputStream masterOutput,
                                java.nio.charset.Charset encoding,
                                Terminal.SignalHandler signalHandler,
                                boolean paused)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • ExternalTerminal

        public ExternalTerminal​(TerminalProvider provider,
                                java.lang.String name,
                                java.lang.String type,
                                java.io.InputStream masterInput,
                                java.io.OutputStream masterOutput,
                                java.nio.charset.Charset encoding,
                                java.nio.charset.Charset stdinEncoding,
                                java.nio.charset.Charset stdoutEncoding,
                                java.nio.charset.Charset stderrEncoding,
                                Terminal.SignalHandler signalHandler,
                                boolean paused)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • ExternalTerminal

        public ExternalTerminal​(TerminalProvider provider,
                                java.lang.String name,
                                java.lang.String type,
                                java.io.InputStream masterInput,
                                java.io.OutputStream masterOutput,
                                java.nio.charset.Charset encoding,
                                Terminal.SignalHandler signalHandler,
                                boolean paused,
                                Attributes attributes,
                                Size size)
                         throws java.io.IOException
        Throws:
        java.io.IOException
      • ExternalTerminal

        public ExternalTerminal​(TerminalProvider provider,
                                java.lang.String name,
                                java.lang.String type,
                                java.io.InputStream masterInput,
                                java.io.OutputStream masterOutput,
                                java.nio.charset.Charset encoding,
                                java.nio.charset.Charset stdinEncoding,
                                java.nio.charset.Charset stdoutEncoding,
                                java.nio.charset.Charset stderrEncoding,
                                Terminal.SignalHandler signalHandler,
                                boolean paused,
                                Attributes attributes,
                                Size size)
                         throws java.io.IOException
        Throws:
        java.io.IOException
    • Method Detail

      • pause

        public void pause()
        Description copied from interface: Terminal
        Temporarily stops reading the input stream.

        This method pauses the terminal's input processing, which can be useful when transferring control to a subprocess or when the terminal needs to be in a specific state for certain operations. While paused, the terminal will not process input or handle signals that would normally be triggered by special characters in the input stream.

        This method returns immediately without waiting for the terminal to actually pause. To wait until the terminal has fully paused, use Terminal.pause(boolean) with a value of true.

        Example usage:

         Terminal terminal = TerminalBuilder.terminal();
        
         // Pause terminal input processing before running a subprocess
         terminal.pause();
        
         // Run subprocess that takes control of the terminal
         Process process = new ProcessBuilder("vim").inheritIO().start();
         process.waitFor();
        
         // Resume terminal input processing
         terminal.resume();
         
        Specified by:
        pause in interface Terminal
        Overrides:
        pause in class AbstractTerminal
        See Also:
        Terminal.resume(), Terminal.pause(boolean), Terminal.paused(), Terminal.canPauseResume()
      • pause

        public void pause​(boolean wait)
                   throws java.lang.InterruptedException
        Description copied from interface: Terminal
        Stop reading the input stream and optionally wait for the underlying threads to finish.
        Specified by:
        pause in interface Terminal
        Overrides:
        pause in class AbstractTerminal
        Parameters:
        wait - true to wait until the terminal is actually paused
        Throws:
        java.lang.InterruptedException - if the call has been interrupted
      • resume

        public void resume()
        Description copied from interface: Terminal
        Resumes reading the input stream after it has been paused.

        This method restarts the terminal's input processing after it has been temporarily stopped using Terminal.pause() or Terminal.pause(boolean). Once resumed, the terminal will continue to process input and handle signals triggered by special characters in the input stream.

        Calling this method when the terminal is not paused has no effect.

        Example usage:

         Terminal terminal = TerminalBuilder.terminal();
        
         // Pause terminal input processing
         terminal.pause();
        
         // Perform operations while terminal input is paused...
        
         // Resume terminal input processing
         terminal.resume();
         
        Specified by:
        resume in interface Terminal
        Overrides:
        resume in class AbstractTerminal
        See Also:
        Terminal.pause(), Terminal.pause(boolean), Terminal.paused(), Terminal.canPauseResume()
      • paused

        public boolean paused()
        Description copied from interface: Terminal
        Check whether the terminal is currently reading the input stream or not. In order to process signal as quickly as possible, the terminal need to read the input stream and buffer it internally so that it can detect specific characters in the input stream (Ctrl+C, Ctrl+D, etc...) and raise the appropriate signals. However, there are some cases where this processing should be disabled, for example when handing the terminal control to a subprocess.
        Specified by:
        paused in interface Terminal
        Overrides:
        paused in class AbstractTerminal
        Returns:
        whether the terminal is currently reading the input stream or not
        See Also:
        Terminal.pause(), Terminal.resume()
      • pump

        public void pump()
      • getCursorPosition

        public Cursor getCursorPosition​(java.util.function.IntConsumer discarded)
        Description copied from interface: Terminal
        Query the terminal to report the cursor position. As the response is read from the input stream, some characters may be read before the cursor position is actually read. Those characters can be given back using org.jline.keymap.BindingReader#runMacro(String)
        Specified by:
        getCursorPosition in interface Terminal
        Overrides:
        getCursorPosition in class AbstractTerminal
        Parameters:
        discarded - a consumer receiving discarded characters
        Returns:
        null if cursor position reporting is not supported or a valid cursor position
      • getProvider

        public TerminalProvider getProvider()
        Description copied from interface: TerminalExt
        Returns the terminal provider that created this terminal.

        The terminal provider is responsible for creating and managing terminal instances on a specific platform. This method allows access to the provider that created this terminal, which can be useful for accessing provider-specific functionality or for creating additional terminals with the same provider.

        Specified by:
        getProvider in interface TerminalExt
        Overrides:
        getProvider in class LineDisciplineTerminal
        Returns:
        the TerminalProvider that created this terminal, or null if the terminal was created with no provider
        See Also:
        TerminalProvider