Class TerminalEnvironment

java.lang.Object
uk.ac.starlink.task.TerminalEnvironment
All Implemented Interfaces:
Environment

public class TerminalEnvironment extends Object implements Environment
Implementation of Environment which accepts an initial command line, and communicates with the user using standard input and standard output.

This environment is somewhat deprecated in favour of the more capable LineEnvironment.

Author:
Mark Taylor (Starlink)
  • Field Details

    • NUM_TRIES

      public static int NUM_TRIES
      The number of goes you get to put in an invalid parameter.
  • Constructor Details

    • TerminalEnvironment

      public TerminalEnvironment(String[] args, Parameter<?>[] params) throws UsageException
      Constructs a new Environment based on a String array containing supplied arguments, and a list of parameters which may be encountered. The initial arguments may have the form value or name=value; in the former case they must correspond to a parameter with a non-zero position attribute indicating where it is expected on the command line, and in the latter case the name must correspond to the name of one of the parameters in params.
      Parameters:
      args - an array of words found on the command line
      params - an array of Parameter objects which this Environment may be asked to get values for
      Throws:
      UsageException
  • Method Details

    • clear

      public void clear(Parameter<?> par)
    • acquireValue

      public void acquireValue(Parameter<?> par) throws TaskException
      Sets the value of a parameter. If it a value has been specified on the command line then that is used, otherwise any known default is used, otherwise the user is prompted on standard output and response got from standard input.

      A more configurable order (cf ADAM PPATH/VPATH) could be implemented by adding some methods to Parameter and getting this method to query them.

      Specified by:
      acquireValue in interface Environment
      Parameters:
      par - the parameter whose value is to be set
      Throws:
      TaskException
    • clearValue

      public void clearValue(Parameter<?> par)
      Description copied from interface: Environment
      Clears a value for a given parameter.
      Specified by:
      clearValue in interface Environment
      Parameters:
      par - the Parameter whose value is to be cleared
    • getNames

      public String[] getNames()
      Description copied from interface: Environment
      Returns an array of parameter names which have been specified. The result is not necessarily an exhaustive list of all parameters whose values can be retrieved from this environment, since an interactive environment may be able to prompt the user for values, but it can give a list of values provided explicitly or without interactive prompts.
      Specified by:
      getNames in interface Environment
      Returns:
      array of names of known supplied parameters
    • getOutputStream

      public PrintStream getOutputStream()
      Returns System.out.
      Specified by:
      getOutputStream in interface Environment
      Returns:
      System.out
    • getErrorStream

      public PrintStream getErrorStream()
      Returns System.err.
      Specified by:
      getErrorStream in interface Environment
      Returns:
      System.err