org.haiku.haikudepotserver.support.FileHelper.java Source code

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Here is the source code for org.haiku.haikudepotserver.support.FileHelper.java

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/*
 * Copyright 2015-2016, Andrew Lindesay
 * Distributed under the terms of the MIT License.
 */

package org.haiku.haikudepotserver.support;

import com.google.common.base.Preconditions;
import com.google.common.io.ByteStreams;
import com.google.common.io.Files;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

public class FileHelper {

    /**
     * <p>This method will stream the data from the supplied URL into the file.  If it is a suitable
     * URL (http / https) then it is possible to provide a timeout and that will be observed when
     * connecting and retreiving data.</p>
     */

    public static void streamUrlDataToFile(URL url, File file, long timeoutMillis) throws IOException {
        switch (url.getProtocol()) {

        case "http":
        case "https":
            HttpURLConnection connection = null;

            try {
                connection = (HttpURLConnection) url.openConnection();

                connection.setConnectTimeout((int) timeoutMillis);
                connection.setReadTimeout((int) timeoutMillis);
                connection.setRequestMethod(HttpMethod.GET.name());
                connection.connect();

                int responseCode = connection.getResponseCode();

                if (responseCode == HttpStatus.OK.value()) {
                    try (InputStream inputStream = connection.getInputStream();
                            OutputStream outputStream = new FileOutputStream(file)) {
                        ByteStreams.copy(inputStream, outputStream);
                    }
                } else {
                    throw new IOException("url request returned " + responseCode);
                }

            } finally {
                if (null != connection) {
                    connection.disconnect();
                }
            }
            break;

        case "file":
            Files.copy(new File(url.getFile()), file);
            break;

        default:
            throw new IllegalStateException("the url scheme of " + url.getProtocol() + " is unsupported.");

        }

    }

    /**
     * <p>This method will delete the file specified recursively.</p>
     */

    public static void delete(File f) throws IOException {
        Preconditions.checkArgument(null != f, "the file must be provided");
        if (f.isDirectory()) {
            for (File c : f.listFiles())
                delete(c);
        }
        if (!f.delete())
            throw new FileNotFoundException("Failed to delete file: " + f);
    }

}