proposal/mutant/src/java/antcore/org/apache/ant/antcore/antlib/DynamicLibrary.java

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Ant", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.ant.antcore.antlib;
import java.util.HashMap;
import java.util.Map;
import org.apache.ant.common.antlib.AntContext;
import org.apache.ant.common.antlib.AntLibFactory;

/**
 * A dynamic library is created at runtime to hold newly defined components.
 *
 * @author <a href="mailto:conor@apache.org">Conor MacNeill</a>
 * @created 8 February 2002
 */
public class DynamicLibrary implements ComponentLibrary {
    /** The name profix for naming dynamic libraries */
    public static final String DYNAMIC_LIB_PREFIX = "_internal";
    /** A static field used to uniquely name dynamic libraries */
    private static int dynamicIdCounter = 0;

    /**
     * the factory this dynamic library will use to create instances of its
     * components
     */
    private AntLibFactory factory;
    /**
     * the classloader that will be used to create new instances of the
     * library's components
     */
    private ClassLoader loader;
    /** the library's unique id */
    private String libraryId;
    /**
     * the component definitions of this library. This map contains
     * AntLibDefinition instances indexed on the definition names.
     */
    private Map definitions = new HashMap();


    /**
     * Constructor for the DynamicLibrary object
     *
     * @param factory the factory to use to create instances. May be null
     * @param loader the loader to use to load the instance classes
     */
    public DynamicLibrary(AntLibFactory factory, ClassLoader loader) {
        int dynamicId = 0;
        synchronized (DynamicLibrary.class) {
            dynamicId = dynamicIdCounter;
            dynamicIdCounter++;
        }
        this.libraryId = DYNAMIC_LIB_PREFIX + dynamicId;
        this.loader = loader;
        this.factory = factory;
    }

    /**
     * Gets the ClassLoader of the AntLibrary
     *
     * @return The ClassLoader value
     */
    public ClassLoader getClassLoader() {
        return loader;
    }

    /**
     * Gat an instance of a factory object for creating objects in this
     * library.
     *
     * @param context the context to use for the factory creation if
     *      required
     * @return an instance of the factory, or null if this library does not
     *      support a factory
     */
    public AntLibFactory getFactory(AntContext context) {
        return factory;
    }

    /**
     * Gets the libraryId of the AntLibrary
     *
     * @return the libraryId value
     */
    public String getLibraryId() {
        return libraryId;
    }

    /**
     * Get the definition of a particular component
     *
     * @param definitionName the name of the component within the library
     * @return an AntLibDefinition instance with information about the
     *      component's definition
     */
    public AntLibDefinition getDefinition(String definitionName) {
        return (AntLibDefinition)definitions.get(definitionName);
    }

    /**
     * Add a new component definition to this library
     *
     * @param componentType the type of the component
     * @param componentName the name of the component
     * @param componentClassName the component's class
     */
    public void addComponent(int componentType, String componentName,
                             String componentClassName) {
        AntLibDefinition newDefinition
             = new AntLibDefinition(componentType, componentName,
            componentClassName);

        definitions.put(componentName, newDefinition);
    }
}