Ant example source code file (ScriptRunnerHelper.java)

This example Ant source code file (ScriptRunnerHelper.java) 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 - Ant tags/keywords

classloader, classloader, file, file, io, path, projectcomponent, scriptrunnerbase, scriptrunnerbase, scriptrunnercreator, scriptrunnerhelper, string, string

The ScriptRunnerHelper.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.apache.tools.ant.util;

import org.apache.tools.ant.ProjectComponent;
import org.apache.tools.ant.types.Path;
import java.io.File;
import org.apache.tools.ant.types.Reference;


/**
 * A class to help in creating, setting and getting
 * script runners.
 */
public class ScriptRunnerHelper {
    private ClasspathUtils.Delegate cpDelegate = null;
    private File    srcFile;
    private String  manager = "auto";
    private String  language;
    private String  text;
    private boolean setBeans = true;
    private ProjectComponent projectComponent;
    private ClassLoader scriptLoader = null;

    /**
     * Set the project component associated with this helper.
     * @param component the project component that owns this helper.
     */
    public void setProjectComponent(ProjectComponent component) {
        this.projectComponent = component;
    }

    /**
     * Create and set text on a script.
     * @return the created or reused script runner.
     */
    public ScriptRunnerBase getScriptRunner() {
        ScriptRunnerBase runner = getRunner();
        if (srcFile != null) {
            runner.setSrc(srcFile);
        }
        if (text != null) {
            runner.addText(text);
        }
        if (setBeans) {
            runner.bindToComponent(projectComponent);
        } else {
            runner.bindToComponentMinimum(projectComponent);
        }
        return runner;
    }

    /**
     * Classpath to be used when searching for classes and resources.
     *
     * @return an empty Path instance to be configured by Ant.
     */
    public Path createClasspath() {
        return getClassPathDelegate().createClasspath();
    }

    /**
     * Set the classpath to be used when searching for classes and resources.
     *
     * @param classpath an Ant Path object containing the search path.
     */
    public void setClasspath(Path classpath) {
        getClassPathDelegate().setClasspath(classpath);
    }

    /**
     * Set the classpath by reference.
     *
     * @param r a Reference to a Path instance to be used as the classpath
     *          value.
     */
    public void setClasspathRef(Reference r) {
        getClassPathDelegate().setClasspathref(r);
    }

    /**
     * Load the script from an external file ; optional.
     *
     * @param file the file containing the script source.
     */
    public void setSrc(File file) {
        this.srcFile = file;
    }

    /**
     * The script text.
     *
     * @param text a component of the script text to be added.
     */
    public void addText(String text) {
        this.text = text;
    }

    /**
     * Defines the script manager - defaults to "auto".
     *
     * @param manager the scripting manager - "bsf" or "javax" or "auto"
     */
    public void setManager(String manager) {
        this.manager = manager;
    }

    /**
     * Defines the language (required).
     *
     * @param language the scripting language name for the script.
     */
    public void setLanguage(String language) {
        this.language = language;
    }

    /**
     * Get the language.
     * @return the scripting language.
     */
    public String getLanguage() {
        return language;
    }

    /**
     * Set the setbeans attribute.
     * If this is true, <script> will create variables in the
     * script instance for all
     * properties, targets and references of the current project.
     * It this is false, only the project and self variables will
     * be set.
     * The default is true.
     * @param setBeans the value to set.
     */
    public void setSetBeans(boolean setBeans) {
        this.setBeans = setBeans;
    }

    /**
     * Used when called by scriptdef.
     * @param loader the loader used by scriptdef.
     */
    public void setClassLoader(ClassLoader loader) {
        scriptLoader = loader;
    }


    private ClassLoader generateClassLoader() {
        if (scriptLoader != null) {
            return scriptLoader;
        }
        if (cpDelegate == null) {
            scriptLoader = getClass().getClassLoader();
            return scriptLoader;
        }

        scriptLoader = cpDelegate.getClassLoader();
        return scriptLoader;
    }

    private ClasspathUtils.Delegate getClassPathDelegate() {
        if (cpDelegate == null) {
            cpDelegate = ClasspathUtils.getDelegate(projectComponent);
        }
        return cpDelegate;
    }

    /**
     * Get a script runner.
     */
    private ScriptRunnerBase getRunner() {
        return new ScriptRunnerCreator(
            projectComponent.getProject()).createRunner(
                manager, language, generateClassLoader());
    }
}