cloudlens.parser.FileReader.java Source code

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Here is the source code for cloudlens.parser.FileReader.java

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/*
 *  This file is part of the CloudLens project.
 *
 * Copyright omitted for blind review
 *
 * 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 cloudlens.parser;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.SequenceInputStream;
import java.net.HttpURLConnection;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Base64;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.io.FilenameUtils;

import cloudlens.engine.CLException;

public class FileReader {

    public static InputStream fetchFile(String urlString) {
        try {
            InputStream inputStream;
            URL url;
            if (urlString.startsWith("local:")) {
                final String path = urlString.replaceFirst("local:", "");
                inputStream = Files.newInputStream(Paths.get(path));
            } else if (urlString.startsWith("file:")) {
                url = new URL(urlString);
                inputStream = Files.newInputStream(Paths.get(url.toURI()));
            } else if (urlString.startsWith("http:") || urlString.startsWith("https:")) {
                url = new URL(urlString);
                final HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setDoInput(true);
                final Matcher matcher = Pattern.compile("//([^@]+)@").matcher(urlString);
                if (matcher.find()) {
                    final String encoding = Base64.getEncoder().encodeToString(matcher.group(1).getBytes());
                    conn.setRequestProperty("Authorization", "Basic " + encoding);
                }
                conn.setRequestMethod("GET");
                inputStream = conn.getInputStream();
            } else {
                throw new CLException("supported protocols are: http, https, file, and local.");
            }
            return inputStream;
        } catch (IOException | URISyntaxException e) {
            throw new CLException(e.getMessage());
        }
    }

    public static ArrayList<String> fullPaths(String[] filePaths) {
        final ArrayList<String> res = new ArrayList<>();
        if (filePaths != null) {
            for (final String filePath : filePaths) {
                final File file = new File(filePath);
                if (!file.exists()) {
                    throw new CLException(filePath + ": no such file.");
                }
                final String filename = file.getName();
                if (!FilenameUtils.getExtension(filename).equals("js")) {
                    throw new CLException(filePath + " is not a JS file.");
                }
                final String abspath = file.getAbsolutePath();
                res.add(abspath);
            }
        }
        return res;

    }

    public static InputStream readFiles(String[] fileNames) throws IOException {
        try {
            final List<InputStream> streams = new ArrayList<>();
            for (final String name : fileNames) {
                streams.add(new FileInputStream(new File(name)));
            }
            final Enumeration<InputStream> files = Collections.enumeration(streams);
            return new SequenceInputStream(files);
        } catch (final IOException e) {
            throw new CLException(e.getMessage());
        }
    }
}