com.ibm.jaggr.core.resource.AggregationResource.java Source code

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Here is the source code for com.ibm.jaggr.core.resource.AggregationResource.java

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/*
 * (C) Copyright 2012, IBM Corporation
 *
 * 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 com.ibm.jaggr.core.resource;

import com.ibm.jaggr.core.readers.AggregationReader;

import org.apache.commons.io.input.ReaderInputStream;

import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;

/**
 * This class implements an aggregating resource that combines the
 * contents of one or more component resources.
 */
public class AggregationResource implements IResource, IResourceVisitor.Resource {

    private final URI facadeUri;
    private final List<IResource> resources;

    public AggregationResource(URI facadeUri, List<IResource> resources) {
        this.facadeUri = facadeUri;
        this.resources = resources;
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#getURI()
     */
    @Override
    public URI getURI() {
        return facadeUri;
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#getPath()
     */
    @Override
    public String getPath() {
        return getURI().getPath();
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#exists()
     */
    @Override
    public boolean exists() {
        // Return false if any of the resources in this aggregated resource
        // does not exist
        boolean result = true;
        for (IResource resource : resources) {
            if (!resource.exists()) {
                result = false;
                break;
            }
        }
        return result;
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#lastModified()
     */
    @Override
    public long lastModified() {
        // return the latest of each of the resources in this aggregated
        // resource
        long result = -1;
        for (IResource resource : resources) {
            result = Math.max(result, resource.lastModified());
        }
        return result;
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#getReader()
     */
    @Override
    public Reader getReader() throws IOException {
        // Return an Aggregation reader for all the resources in this
        // aggregated resource
        List<Reader> readers = new ArrayList<Reader>(resources.size());
        for (IResource resource : resources) {
            readers.add(resource.getReader());
        }
        return new AggregationReader(readers);
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#getInputStream()
     */
    @Override
    public InputStream getInputStream() throws IOException {
        return new ReaderInputStream(getReader(), "UTF-8"); //$NON-NLS-1$
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#walkTree(com.ibm.jaggr.core.resource.IResourceVisitor)
     */
    @Override
    public void walkTree(IResourceVisitor visitor) throws IOException {
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#asVisitorResource()
     */
    @Override
    public IResourceVisitor.Resource asVisitorResource() throws IOException {
        return this;
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResourceVisitor.Resource#isFolder()
     */
    @Override
    public boolean isFolder() {
        return false;
    }

    /* (non-Javadoc)
     * @see com.ibm.jaggr.core.resource.IResource#resolve(java.lang.String)
     */
    @Override
    public IResource resolve(String relative) {
        throw new UnsupportedOperationException();
    }
}