001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 * 
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 * 
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.launcher;
019
020import org.apache.tools.ant.BuildException;
021
022/**
023 * An interface that provides a means for application developers to perform
024 * dynamic configuration and error checking of the attributes and nested
025 * elements associated with a "launch" task that connot be easily done within 
026 * the constraints of Ant.
027 * <p>
028 * An implementor of this interface can be attached to a "launch" task by
029 * setting the following "launch" task attributes in the Launcher's XML
030 * file:
031 * <ul>
032 * <li><code>filterclassname</code> - The name of the class that implements
033 * this interface
034 * <li><code>filterclasspath</code> - (Optional) The classpath for the class
035 * that implements
036 * </ul>
037 *
038 * @author Patrick Luby
039 */
040public interface LaunchFilter {
041
042    //----------------------------------------------------------------- Methods
043
044    /**
045     * Perform error checking and editing of the JVM command line arguments
046     * that an instance of the {@link LaunchTask} class has constructed.
047     * Implementors will receive an instance of the {@link LaunchCommand} from
048     * the {@link LaunchTask} instance that invokes this method. The
049     * implementor of this method can then retrieve and edit any of the
050     * JVM command line arguments via the {@link LaunchCommand} class' public
051     * methods.
052     *
053     * @param launchCommand a configured {@link LaunchCommand} instance
054     * @throws BuildException if any errors occur
055     */
056    public void filter(LaunchCommand launchCommand) throws BuildException;
057
058}