Ant example source code file (Description.java)

This example Ant source code file (Description.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

datatype, description, projecthelper, projecthelperimpl, string, string, stringbuffer, target, target, task, task, unknownelement, util, vector, vector

The Description.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.types;

import org.apache.tools.ant.Project;
import org.apache.tools.ant.ProjectHelper;
import org.apache.tools.ant.Task;
import org.apache.tools.ant.UnknownElement;
import org.apache.tools.ant.Target;
import org.apache.tools.ant.helper.ProjectHelperImpl;

import java.util.Vector;


/**
 * Description is used to provide a project-wide description element
 * (that is, a description that applies to a buildfile as a whole).
 * If present, the <description> element is printed out before the
 * target descriptions.
 *
 * Description has no attributes, only text.  There can only be one
 * project description per project.  A second description element will
 * overwrite the first.
 *
 *
 * @ant.datatype ignore="true"
 */
public class Description extends DataType {

    /**
     * Adds descriptive text to the project.
     *
     * @param text the descriptive text
     */
    public void addText(String text) {

        ProjectHelper ph = ProjectHelper.getProjectHelper();
        if (!(ph instanceof ProjectHelperImpl)) {
            // New behavior for delayed task creation. Description
            // will be evaluated in Project.getDescription()
            return;
        }
        String currentDescription = getProject().getDescription();
        if (currentDescription == null) {
            getProject().setDescription(text);
        } else {
            getProject().setDescription(currentDescription + text);
        }
    }

    /**
     * Return the descriptions from all the targets of
     * a project.
     *
     * @param project the project to get the descriptions for.
     * @return a string containing the concatenated descriptions of
     *         the targets.
     */
    public static String getDescription(Project project) {
        Vector targets = (Vector) project.getReference("ant.targets");
        if (targets == null) {
            return null;
        }
        StringBuffer description = new StringBuffer();
        for (int i = 0; i < targets.size(); i++) {
            Target t = (Target) targets.elementAt(i);
            concatDescriptions(project, t, description);
        }
        return description.toString();
    }

    private static void concatDescriptions(Project project, Target t,
                                           StringBuffer description) {
        if (t == null) {
            return;
        }
        Vector tasks = findElementInTarget(project, t, "description");
        if (tasks == null) {
            return;
        }
        for (int i = 0; i < tasks.size(); i++) {
            Task task = (Task) tasks.elementAt(i);
            if (!(task instanceof UnknownElement)) {
                continue;
            }
            UnknownElement ue = ((UnknownElement) task);
            String descComp = ue.getWrapper().getText().toString();
            if (descComp != null) {
                description.append(project.replaceProperties(descComp));
            }
        }
    }

    private static Vector findElementInTarget(Project project,
                                              Target t, String name) {
        Task[] tasks = t.getTasks();
        Vector elems = new Vector();
        for (int i = 0; i < tasks.length; i++) {
            if (name.equals(tasks[i].getTaskName())) {
                elems.addElement(tasks[i]);
            }
        }
        return elems;
    }

}