Class TerminalEnvironment

  • All Implemented Interfaces:
    Environment

    public class TerminalEnvironment
    extends java.lang.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 Summary

      Fields 
      Modifier and Type Field Description
      static int NUM_TRIES
      The number of goes you get to put in an invalid parameter.
    • Constructor Summary

      Constructors 
      Constructor Description
      TerminalEnvironment​(java.lang.String[] args, Parameter[] params)
      Constructs a new Environment based on a String array containing supplied arguments, and a list of parameters which may be encountered.
    • Field Detail

      • NUM_TRIES

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

      • TerminalEnvironment

        public TerminalEnvironment​(java.lang.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 Detail

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

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