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Groovy example source code file (AntBuilder.java)

This example Groovy source code file (AntBuilder.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 - Groovy tags/keywords

antbuilder, buildexception, io, log, logging, object, object, printstream, project, project, reflection, runtimeconfigurable, sax, string, string, target, target, task, unknownelement, util

The Groovy AntBuilder.java source code

/*
 * Copyright 2003-2011 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 groovy.util;

import groovy.xml.QName;
import org.apache.tools.ant.*;
import org.apache.tools.ant.dispatch.DispatchUtils;
import org.apache.tools.ant.helper.AntXMLContext;
import org.apache.tools.ant.helper.ProjectHelper2;
import org.codehaus.groovy.ant.FileScanner;
import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.AttributesImpl;

import java.io.InputStream;
import java.io.PrintStream;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Allows <a href="http://ant.apache.org/manual/coretasklist.html">Ant tasks to
 * be used with a Groovy builder-style markup. Requires that {{ant.jar}} is on your classpath which will
 * happen automatically if you are using the Groovy distribution but will be up
 * to you to organize if you are embedding Groovy. If you wish to use the
 * <a href="http://ant.apache.org/manual/install#optionalTasks">optional tasks
 * you will need to add one or more additional jars from the ant distribution to
 * your classpath - see the <a href="http://ant.apache.org/manual/install.html#librarydependencies">library
 * dependencies</a> for more details.
 *
 * @author <a href="mailto:james@coredevelopers.net">James Strachan
 * @author Dierk Koenig (dk)
 * @author Marc Guillemot
 */
public class AntBuilder extends BuilderSupport {

    private final Logger log = Logger.getLogger(getClass().getName());
    private Project project;
    private final AntXMLContext antXmlContext;
    private final ProjectHelper2.ElementHandler antElementHandler = new ProjectHelper2.ElementHandler();
    private final ProjectHelper2.TargetHandler antTargetHandler = new ProjectHelper2.TargetHandler();
    private final Target collectorTarget;
    private final Target implicitTarget;
    private Object lastCompletedNode;
    // true when inside a task so special ant.target handling occurs just at top level
    boolean insideTask;

    public AntBuilder() {
        this(createProject());
    }

    public AntBuilder(final Project project) {
        this(project, new Target());
    }

    public AntBuilder(final Project project, final Target owningTarget) {
        this.project = project;

        /*
         * GROOVY-4524: The following is not needed anymore as an ant Project already by default has inputhandler
         * set to DefaultInputHandler. And if it is again set here, it mistakenly overrides the custom input handler
         * if set using -inputhandler switch. 
         */
        //this.project.setInputHandler(new DefaultInputHandler());

        collectorTarget = owningTarget;
        antXmlContext = new AntXMLContext(project);
        collectorTarget.setProject(project);
        antXmlContext.setCurrentTarget(collectorTarget);
        antXmlContext.setLocator(new AntBuilderLocator());
        antXmlContext.setCurrentTargets(new HashMap());

        implicitTarget = new Target();
        implicitTarget.setProject(project);
        implicitTarget.setName("");
        antXmlContext.setImplicitTarget(implicitTarget);

        // FileScanner is a Groovy hack (utility?)
        project.addDataTypeDefinition("fileScanner", FileScanner.class);
    }

    public AntBuilder(final Task parentTask) {
        this(parentTask.getProject(), parentTask.getOwningTarget());

        // define "owning" task as wrapper to avoid having tasks added to the target
        // but it needs to be an UnknownElement and no access is available from
        // task to its original UnknownElement 
        final UnknownElement ue = new UnknownElement(parentTask.getTaskName());
        ue.setProject(parentTask.getProject());
        ue.setTaskType(parentTask.getTaskType());
        ue.setTaskName(parentTask.getTaskName());
        ue.setLocation(parentTask.getLocation());
        ue.setOwningTarget(parentTask.getOwningTarget());
        ue.setRuntimeConfigurableWrapper(parentTask.getRuntimeConfigurableWrapper());
        parentTask.getRuntimeConfigurableWrapper().setProxy(ue);
        antXmlContext.pushWrapper(parentTask.getRuntimeConfigurableWrapper());
    }

    /**
     * #
     * Gets the Ant project in which the tasks are executed
     *
     * @return the project
     */
    public Project getProject() {
        return project;
    }

    /**
     * Gets the xml context of Ant used while creating tasks
     *
     * @return the Ant xml context
     */
    public AntXMLContext getAntXmlContext() {
        return antXmlContext;
    }

    /**
     * @return Factory method to create new Project instances
     */
    protected static Project createProject() {
        final Project project = new Project();

        final ProjectHelper helper = ProjectHelper.getProjectHelper();
        project.addReference(ProjectHelper.PROJECTHELPER_REFERENCE, helper);
        helper.getImportStack().addElement("AntBuilder"); // import checks that stack is not empty 

        final BuildLogger logger = new NoBannerLogger();

        logger.setMessageOutputLevel(org.apache.tools.ant.Project.MSG_INFO);
        logger.setOutputPrintStream(System.out);
        logger.setErrorPrintStream(System.err);

        project.addBuildListener(logger);

        project.init();
        project.getBaseDir();
        return project;
    }

    protected void setParent(Object parent, Object child) {
    }

    /**
     * We don't want to return the node as created in {@link #createNode(Object, Map, Object)}
     * but the one made ready by {@link #nodeCompleted(Object, Object)}
     *
     * @see groovy.util.BuilderSupport#doInvokeMethod(java.lang.String, java.lang.Object, java.lang.Object)
     */
    protected Object doInvokeMethod(String methodName, Object name, Object args) {
        super.doInvokeMethod(methodName, name, args);


        // return the completed node
        return lastCompletedNode;
    }

    /**
     * Determines, when the ANT Task that is represented by the "node" should perform.
     * Node must be an ANT Task or no "perform" is called.
     * If node is an ANT Task, it performs right after complete construction.
     * If node is nested in a TaskContainer, calling "perform" is delegated to that
     * TaskContainer.
     *
     * @param parent note: null when node is root
     * @param node   the node that now has all its children applied
     */
    protected void nodeCompleted(final Object parent, final Object node) {
        if (parent == null) insideTask = false;
        antElementHandler.onEndElement(null, null, antXmlContext);

        lastCompletedNode = node;
        if (parent != null && !(parent instanceof Target)) {
            log.finest("parent is not null: no perform on nodeCompleted");
            return; // parent will care about when children perform
        }

        // as in Target.execute()
        if (node instanceof Task) {
            Task task = (Task) node;
            final String taskName = task.getTaskName();

            if ("antcall".equals(taskName) && parent == null) {
                throw new BuildException("antcall not supported within AntBuilder, consider using 'ant.project.executeTarget('targetName')' instead.");
            }

            // save original streams
            InputStream savedProjectInputStream = project.getDefaultInputStream();
            InputStream savedIn = System.in;
            PrintStream savedErr = System.err;
            PrintStream savedOut = System.out;

            if (!(savedIn instanceof DemuxInputStream)) {
                project.setDefaultInputStream(savedIn);
                System.setIn(new DemuxInputStream(project));
            }
            System.setOut(new PrintStream(new DemuxOutputStream(project, false)));
            System.setErr(new PrintStream(new DemuxOutputStream(project, true)));

            try {
                lastCompletedNode = performTask(task);
            } finally {
                // restore original streams
                project.setDefaultInputStream(savedProjectInputStream);
                System.setIn(savedIn);
                System.setOut(savedOut);
                System.setErr(savedErr);
            }

            // restore dummy collector target
            if ("import".equals(taskName)) {
                antXmlContext.setCurrentTarget(collectorTarget);
            }
        } else if (node instanceof Target) {
            // restore dummy collector target
            antXmlContext.setCurrentTarget(collectorTarget);
        } else {
            final RuntimeConfigurable r = (RuntimeConfigurable) node;
            r.maybeConfigure(project);
        }
    }

    // Copied from org.apache.tools.ant.Task, since we need to get a real thing before it gets nulled in DispatchUtils.execute

    private Object performTask(Task task) {

        Throwable reason = null;
        try {
            // Have to call fireTestStared/fireTestFinished via reflection as they unfortunately have protected access in Project
            final Method fireTaskStarted = Project.class.getDeclaredMethod("fireTaskStarted", Task.class);
            fireTaskStarted.setAccessible(true);
            fireTaskStarted.invoke(project, task);

            Object realThing;
            realThing = task;
            task.maybeConfigure();
            if (task instanceof UnknownElement) {
                realThing = ((UnknownElement) task).getRealThing();
            }

            DispatchUtils.execute(task);

            return realThing != null ? realThing : task;
        }
        catch (BuildException ex) {
            if (ex.getLocation() == Location.UNKNOWN_LOCATION) {
                ex.setLocation(task.getLocation());
            }
            reason = ex;
            throw ex;
        }
        catch (Exception ex) {
            reason = ex;
            BuildException be = new BuildException(ex);
            be.setLocation(task.getLocation());
            throw be;
        }
        catch (Error ex) {
            reason = ex;
            throw ex;
        }
        finally {
            try {
                final Method fireTaskFinished = Project.class.getDeclaredMethod("fireTaskFinished", Task.class, Throwable.class);
                fireTaskFinished.setAccessible(true);
                fireTaskFinished.invoke(project, task, reason);
            }
            catch (Exception e) {
                BuildException be = new BuildException(e);
                be.setLocation(task.getLocation());
                throw be;
            }
        }
    }

    protected Object createNode(Object tagName) {
        return createNode(tagName, Collections.EMPTY_MAP);
    }

    protected Object createNode(Object name, Object value) {
        Object task = createNode(name);
        setText(task, value.toString());
        return task;
    }

    protected Object createNode(Object name, Map attributes, Object value) {
        Object task = createNode(name, attributes);
        setText(task, value.toString());
        return task;
    }

    /**
     * Builds an {@link Attributes} from a {@link Map}
     *
     * @param attributes the attributes to wrap
     * @return the wrapped attributes
     */
    protected static Attributes buildAttributes(final Map attributes) {
        final AttributesImpl attr = new AttributesImpl();
        for (Object o : attributes.entrySet()) {
            final Map.Entry entry = (Map.Entry) o;
            final String attributeName = (String) entry.getKey();
            final String attributeValue = String.valueOf(entry.getValue());
            attr.addAttribute(null, attributeName, attributeName, "CDATA", attributeValue);
        }
        return attr;
    }

    protected Object createNode(final Object name, final Map attributes) {

        final Attributes attrs = buildAttributes(attributes);
        String tagName = name.toString();
        String ns = "";

        if (name instanceof QName) {
            QName q = (QName) name;
            tagName = q.getLocalPart();
            ns = q.getNamespaceURI();
        }

        // import can be used only as top level element
        if ("import".equals(name)) {
            antXmlContext.setCurrentTarget(implicitTarget);
        } else if ("target".equals(name) && !insideTask) {
            return onStartTarget(attrs, tagName, ns);
        }

        try {
            antElementHandler.onStartElement(ns, tagName, tagName, attrs, antXmlContext);
        }
        catch (final SAXParseException e) {
            log.log(Level.SEVERE, "Caught: " + e, e);
        }

        insideTask = true;
        final RuntimeConfigurable wrapper = (RuntimeConfigurable) antXmlContext.getWrapperStack().lastElement();
        return wrapper.getProxy();
    }

    private Target onStartTarget(final Attributes attrs, String tagName, String ns) {
        final Target target = new Target();
        target.setProject(project);
        target.setLocation(new Location(antXmlContext.getLocator()));
        try {
            antTargetHandler.onStartElement(ns, tagName, tagName, attrs, antXmlContext);
            final Target newTarget = (Target) getProject().getTargets().get(attrs.getValue("name"));

            // execute dependencies (if any)
            final Vector targets = new Vector();
            for (final Enumeration deps = newTarget.getDependencies(); deps.hasMoreElements();) {
                final String targetName = (String) deps.nextElement();
                targets.add(project.getTargets().get(targetName));
            }
            getProject().executeSortedTargets(targets);

            antXmlContext.setCurrentTarget(newTarget);
            return newTarget;
        }
        catch (final SAXParseException e) {
            log.log(Level.SEVERE, "Caught: " + e, e);
        }
        return null;
    }

    protected void setText(Object task, String text) {
        final char[] characters = text.toCharArray();
        try {
            antElementHandler.characters(characters, 0, characters.length, antXmlContext);
        }
        catch (final SAXParseException e) {
            log.log(Level.WARNING, "SetText failed: " + task + ". Reason: " + e, e);
        }
    }

    public Project getAntProject() {
        return project;
    }
}

/**
 * Would be nice to retrieve location information (from AST?).
 * In a first time, without info
 */
class AntBuilderLocator implements Locator {
    public int getColumnNumber() {
        return 0;
    }

    public int getLineNumber() {
        return 0;
    }

    public String getPublicId() {
        return "";
    }

    public String getSystemId() {
        return "";
    }
}

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