com.sangupta.jerry.util.WebUtils.java Source code

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Here is the source code for com.sangupta.jerry.util.WebUtils.java

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/**
 *
 * jerry-http - Common Java Functionality
 * Copyright (c) 2012-2015, Sandeep Gupta
 * 
 * http://sangupta.com/projects/jerry-http
 * 
 * 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.sangupta.jerry.util;

import java.io.File;
import java.io.IOException;

import org.apache.http.client.HttpResponseException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.sangupta.jerry.http.WebRequest;

/**
 * Function to handle file downloads from the web via HTTP. More schemes
 * may be added in future.
 * 
 * @author sangupta
 *
 */
public class WebUtils {

    /**
     * My logger instance
     */
    private static final Logger logger = LoggerFactory.getLogger(WebUtils.class);

    /**
     * Download the file at the given location URL and store it as a temporary
     * file on disk. The temporary file is set to be deleted at the exit of the
     * application.
     * 
     * @param url
     *            absolute URL of the file
     * 
     * @return {@link File} handle of the temporary file that was written to
     *         disk if successful, <code>null</code> otherwise.
     * 
     * @throws IOException
     *             in case something fails
     */
    public static File downloadToTempFile(String url) throws IOException {
        String extension = UriUtils.extractExtension(url);
        File tempFile = File.createTempFile("download", extension);
        tempFile.deleteOnExit();

        logger.debug("Downloading {} to {}", url, tempFile.getAbsolutePath());

        try {
            WebRequest.get(url).execute().writeToFile(tempFile);
            return tempFile;
        } catch (HttpResponseException e) {
            logger.error("HTTP response did not yield an OK status", e);
        } catch (IOException e) {
            logger.error("Unable to download url to temp file", e);
        }

        return null;
    }

    /**
     * Download the file at the given location URL and store it in the file
     * mentioned on disk. If the file exists, it will be over-written.
     * 
     * @param url
     *            absolute URL of the file
     * 
     * @param fileToDownloadIn
     *            {@link File} in which contents are written
     * 
     * @return <code>true</code> if file was successfully downloaded,
     *         <code>false</code> otherwise.
     * 
     * @throws IOException
     *             in case something fails
     */
    public static boolean downloadToFile(String url, File fileToDownloadIn) throws IOException {
        try {
            WebRequest.get(url).execute().writeToFile(fileToDownloadIn);
            return true;
        } catch (HttpResponseException e) {
            logger.error("HTTP response did not yield an OK status", e);
        } catch (IOException e) {
            logger.error("Unable to download url to temp file", e);
        }

        return false;
    }

}