Parameter.java

/*
 * JOnAS: Java(TM) Open Application Server
 * Copyright (C) 1999 Bull S.A.
 * Contact: jonas-team@objectweb.org
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *
 * Initial developer(s): Nicolas Christin
 * Contributor(s): ______________________________________.
 *
 * --------------------------------------------------------------------------
 * $Id: Parameter.java,v 1.6 2003/11/21 01:13:08 skrupanszky Exp $
 * --------------------------------------------------------------------------
 */


package org.objectweb.jonas.newbean;


import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

import org.apache.velocity.VelocityContext;


public abstract class Parameter {

    private static final String PROMPT = "> ";
    private static final int INPUT_BUFFER_SIZE = 80;
    private static BufferedReader reader =
        new BufferedReader(new InputStreamReader(System.in));

    protected VelocityContext vContext = null;

    protected String value = null;

    
    public Parameter(VelocityContext context) {
        vContext = context;
    }


    public void walkThrough() {
        obtainValue();
        export();
        Parameter nextParameter = getNextParameter();
        if (nextParameter != null) {
            nextParameter.walkThrough();
        }
    }


    public void obtainValue() {

                // check first if a cmd-line value has been specified
                String  inp = getCmdArg( getArgKeyword() );
                if( inp!=null ) {
                        setValue(inp);
                        if( isValid() ) { return; }
                }

        for (;;) {
            String input = null;
            System.out.println(getPrompt());
            System.out.print("> ");
            try {
                input = reader.readLine();
            } catch (IOException e) {
                NewBean.error(e.toString());
            }
            if (input == null) {
                input = "";
            }
            setValue(input);
            if (isValid())
                break;
            System.out.println("Invalid value, please retry");
        }
        System.out.println();
    }


    public void setValue(String input) {
        value = input;
    }


    public abstract String getPrompt();


    public abstract boolean isValid();


    public abstract void export();


    public abstract Parameter getNextParameter();

        public abstract String          getArgKeyword();

        private String                          getCmdArg( String kwd )
        {
                return (String)NewBean.commandLine.get( kwd );
        }

}

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