home | career | drupal | java | mac | mysql | perl | scala | uml | unix

Groovy example source code file (ShellRunner.groovy)

This example Groovy source code file (ShellRunner.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Groovy tags/keywords

closure, exitnotification, logger, read, runnable, shell, shell, shellrunner, shellrunner, string, string, throwable, work, work

The Groovy ShellRunner.groovy source code

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.codehaus.groovy.tools.shell

import org.codehaus.groovy.tools.shell.util.Logger

/**
 * Support for running a {@link Shell}.
 *
 * @version $Id: ShellRunner.groovy 21140 2010-11-28 19:50:55Z hamletdrc $
 * @author <a href="mailto:jason@planet57.com">Jason Dillon
 */
abstract class ShellRunner
    implements Runnable
{
    protected final Logger log = Logger.create(this.class)
    
    final Shell shell
    
    boolean running = false
    
    boolean breakOnNull = true
    
    Closure errorHandler = { e ->
        log.debug(e)
        
        running = false
    }
    
    ShellRunner(final Shell shell) {
        assert shell
        
        this.shell = shell
    }
    
    void run() {
        log.debug('Running')
        
        running = true
        
        while (running) {
            try {
                running = work()
            }
            catch (ExitNotification n) {
                throw n
            }
            catch (Throwable t) {
                log.debug("Work failed: $t", t)
                
                if (errorHandler) {
                    errorHandler.call(t)
                }
            }
        }
        
        log.debug('Finished')
    }
    
    protected boolean work() {
        def line = readLine()
        
        if (log.debugEnabled) {
            log.debug("Read line: $line")
        }
        
        // Stop on null (maybe)
        if (line == null && breakOnNull) {
            return false // stop the loop
        }
        
        // Ignore empty lines
        if (line.trim().size() > 0) {
            def result = shell << line
        }
        
        return true
    }
    
    protected abstract String readLine()
}

Other Groovy examples (source code examples)

Here is a short list of links related to this Groovy ShellRunner.groovy source code file:

new blog posts

 

Copyright 1998-2014 Alvin Alexander, alvinalexander.com
All Rights Reserved.