src/main/java/org/apache/sling/launcher/app/ResourceProvider.java

/*
 * 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.sling.launcher.app;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Iterator;

/**
 * The <code>ResourceProvider</code> defines a simple API to access resources
 * from the environment depending on how Sling is launched.
 */
public abstract class ResourceProvider {

    /**
     * Returns an iterator of paths strings of the children of the given folder
     * defined by its path.
     */
    public abstract Iterator<String> getChildren(String path);

    /**
     * Returns an URL to the resource with the given path or <code>null</code>
     * if no such resource exists.
     */
    public abstract URL getResource(String path);

    /**
     * Returns an <code>InputStream</code> to the resource given by the path
     * or <code>null</code> if no such resource exists.
     */
    public InputStream getResourceAsStream(String path) {
        URL res = this.getResource(path);
        if (res != null) {
            try {
                return res.openStream();
            } catch (IOException ioe) {
                // ignore this one
            }
        }

        // no resource
        return null;
    }
}