Ant example source code file (ResourceCount.java)

This example Ant source code file (ResourceCount.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

buildexception, buildexception, comparison, integer, object, one_nested_message, resourcecollection, resourcecollection, resourcecount, resourcecount, string, string, task, use

The ResourceCount.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.taskdefs;

import org.apache.tools.ant.Task;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.taskdefs.condition.Condition;
import org.apache.tools.ant.types.Reference;
import org.apache.tools.ant.types.Comparison;
import org.apache.tools.ant.types.ResourceCollection;

/**
 * Count resources from a ResourceCollection, storing to a property or
 * writing to the log.  Can also be used as a Condition.
 * @since Ant 1.7
 */
public class ResourceCount extends Task implements Condition {

    private static final String ONE_NESTED_MESSAGE
        = "ResourceCount can count resources from exactly one nested ResourceCollection.";

    private static final String COUNT_REQUIRED
        = "Use of the ResourceCount condition requires that the count attribute be set.";

    private ResourceCollection rc;
    private Comparison when = Comparison.EQUAL;
    private Integer count;
    private String property;

    /**
     * Add the ResourceCollection to count.
     * @param r the ResourceCollection to count.
     * @throws BuildException if already set.
     */
    public void add(ResourceCollection r) {
        if (rc != null) {
            throw new BuildException(ONE_NESTED_MESSAGE);
        }
        rc = r;
    }

    /**
     * Set the ResourceCollection reference.
     * @param r the Reference.
     */
    public void setRefid(Reference r) {
        Object o = r.getReferencedObject();
        if (!(o instanceof ResourceCollection)) {
            throw new BuildException(r.getRefId()
                + " doesn\'t denote a ResourceCollection");
        }
        add((ResourceCollection) o);
    }

    /**
     * Execute as a Task.
     */
    public void execute() {
        if (rc == null) {
            throw new BuildException(ONE_NESTED_MESSAGE);
        }
        if (property == null) {
            log("resource count = " + rc.size());
        } else {
            getProject().setNewProperty(property, Integer.toString(rc.size()));
        }
    }

    /**
     * Fulfill the condition contract.
     * @return true if the specified ResourceCollection satisfies the set criteria.
     * @throws BuildException if an error occurs.
     */
    public boolean eval() {
        if (rc == null) {
            throw new BuildException(ONE_NESTED_MESSAGE);
        }
        if (count == null) {
            throw new BuildException(COUNT_REQUIRED);
        }
        return when.evaluate(new Integer(rc.size()).compareTo(count));
    }

    /**
     * Set the target count number for use as a Condition.
     * @param c number of Resources as int.
     */
    public void setCount(int c) {
        count = new Integer(c);
    }

    /**
     * Set the comparison for use as a Condition.
     * @param c Comparison (an EnumeratedAttribute) When.
     * @see org.apache.tools.ant.types.Comparison
     */
    public void setWhen(Comparison c) {
        when = c;
    }

    /**
     * Set the name of the property to set in task mode.
     * @param p the property name to set.
     */
    public void setProperty(String p) {
        property = p;
    }

}