pt.webdetails.cpf.packager.dependencies.JsMinifiedDependency.java Source code

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Here is the source code for pt.webdetails.cpf.packager.dependencies.JsMinifiedDependency.java

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/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

package pt.webdetails.cpf.packager.dependencies;

import org.apache.commons.io.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import pt.webdetails.cpf.Util;
import pt.webdetails.cpf.context.api.IUrlProvider;
import pt.webdetails.cpf.packager.origin.PathOrigin;
import pt.webdetails.cpf.repository.api.IRWAccess;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.SequenceInputStream;
import java.text.ParseException;
import java.util.Enumeration;
import java.util.Iterator;

/**
 * Minifies javascript files using {@link JSMin}.
 */
public class JsMinifiedDependency extends PackagedFileDependency {

    private static Log logger = LogFactory.getLog(JsMinifiedDependency.class);

    public JsMinifiedDependency(PathOrigin origin, String path, IRWAccess writer,
            Iterable<FileDependency> inputFiles, IUrlProvider urlProvider) {
        super(origin, path, writer, inputFiles, urlProvider);
    }

    @Override
    protected InputStream minifyPackage(Iterable<FileDependency> inputFiles) {
        return new SequenceInputStream(new JsMinificationEnumeration(inputFiles.iterator()));
    }

    public static class JsMinificationEnumeration implements Enumeration<InputStream> {

        private Iterator<FileDependency> deps;

        public JsMinificationEnumeration(Iterator<FileDependency> deps) {
            this.deps = deps;
        }

        @Override
        public boolean hasMoreElements() {
            return deps.hasNext();
        }

        @Override
        public InputStream nextElement() {
            FileDependency dep = deps.next();
            InputStream input = null;
            try {
                input = dep.getFileInputStream();
                ByteArrayOutputStream bytesOut = new ByteArrayOutputStream();
                JSMin jsMin = new JSMin(input, bytesOut);
                jsMin.jsmin();
                return new ByteArrayInputStream(bytesOut.toByteArray());
            } catch (ParseException e) {
                logger.error("Error parsing javascript dependency " + dep + " at offset " + e.getErrorOffset()
                        + ". Skipping..", e);
            } catch (IOException e) {
                logger.error("Error getting input stream for dependency " + dep + ". Skipping..", e);
            } catch (Exception e) {
                logger.error(String.format("Error while processing dependency %s. Skipping..", dep));
            } finally {
                IOUtils.closeQuietly(input);
            }
            return Util.toInputStream("");
        }

    }

}