com.arm.mbed.cloud.sdk.common.FileDownload Maven / Gradle / Ivy
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package com.arm.mbed.cloud.sdk.common;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
import com.arm.mbed.cloud.sdk.annotations.Preamble;
@Preamble(description = "File on the disk resulting from a download or where some content will be downloaded")
public class FileDownload {
private static final String EMPTY_STRING = "";
private static final String EXTENSION_SEPARATOR = ".";
private static final String UNDEFINED_DESTINATION_FILENAME = "unknown.txt";
private final URL source;
private final File destination;
private boolean downloaded;
private SdkLogger logger;
public enum Extension {
JSON,
TXT,
GZ,
CSV,
DEFAULT
}
/**
* Constructor.
*
* The file will be downloaded from the source to the destination.
*
* @param source
* URL of the source.
* @param destination
* destination file.
*/
public FileDownload(URL source, File destination) {
super();
this.source = source;
this.destination = destination;
this.downloaded = false;
this.logger = null;
}
/**
* Constructor.
*
* The file will be downloaded from the source to a temporary file on the disk.
*
* @param source
* URL of the source.
* @throws MbedCloudException
* if a problem occurred during the process
*/
public FileDownload(URL source) throws MbedCloudException {
this(source, generateTempFile(source, null));
}
/**
* Constructor.
*
* The file will be downloaded from the source to the destination.
*
* @param sourceUrl
* URL of the source.
* @param filePath
* directory on disk where the file should be downloaded or path to the end file.
* @param fileName
* filename of the downloaded file if not specified in filePath
* @throws MalformedURLException
* if a problem occurred during the process
* @throws MbedCloudException
* if a problem occurred during the process
*/
public FileDownload(String sourceUrl, String filePath, String fileName) throws MalformedURLException,
MbedCloudException {
this(new URL(sourceUrl), generateFileDestination(filePath, fileName));
}
/**
* Constructor.
*
* The file will be downloaded from the source to the destination.
*
* @param sourceUrl
* URL of the source.
* @param destinationPath
* destination file path on the disk.
* @throws MalformedURLException
* if a problem occurred during the process
*/
public FileDownload(String sourceUrl, String destinationPath) throws MalformedURLException {
this(new URL(sourceUrl), new File(destinationPath));
}
/**
* Constructor.
*
* @param destination
* destination file on the disk.
*/
public FileDownload(File destination) {
this(null, destination);
}
/**
* Constructor.
*
* @param destinationPath
* destination file path on the disk.
*/
public FileDownload(String destinationPath) {
this(new File(destinationPath));
}
/**
* Constructor.
*
* Note: the data will be saved to a temporary file on the disk.
*
* @param extension
* extension of the destination file on the disk.
* @throws MbedCloudException
* if a problem occurred during the process
*/
public FileDownload(Extension extension) throws MbedCloudException {
this(generateTempFile((String) null,
extension == Extension.DEFAULT ? null : EXTENSION_SEPARATOR + extension.toString().toLowerCase()));
}
/**
* Constructor.
*
* Note: the data will be saved to a temporary file on the disk.
*
* @throws MbedCloudException
* if a problem occurred during the process
*
*
*/
public FileDownload() throws MbedCloudException {
this(Extension.DEFAULT);
}
/**
* Gets download source.
*
* @return the source
*/
public URL getSource() {
return source;
}
/**
* Gets file destination.
*
* @return the destination
*/
public File getDestination() {
return destination;
}
/**
* Has the file been downloaded.
*
* @return the downloaded
*/
public boolean isDownloaded() {
return downloaded;
}
/**
* Sets whether the file has been downloaded.
*
* @param downloaded
* the downloaded to set
*/
public void setDownloaded(boolean downloaded) {
this.downloaded = downloaded;
}
/**
* Sets the logger.
*
* @param logger
* the logger to set
*/
public void setLogger(SdkLogger logger) {
this.logger = logger;
}
/**
* Downloading data to a file on the disk.
*
* @param content
* content to save
* @throws MbedCloudException
* if a problem occurred during the process
*/
public void download(String content) throws MbedCloudException {
checkParameters();
if (content == null) {
throw new MbedCloudException("The file to download is empty");
}
if (logger != null) {
logger.logInfo("Downloading data to [" + destination.getName() + "]");
}
try (PrintWriter out = new PrintWriter(destination, StandardCharsets.UTF_8.name())) {
out.println(content);
} catch (IOException exception) {
throw new MbedCloudException("The file could not be downloaded", exception);
}
downloaded = true;
}
/**
* Downloading a file to the disk.
*
* @throws MbedCloudException
* if a problem occurred during the process
*/
public void download() throws MbedCloudException {
checkParameters();
if (source == null) {
throw new MbedCloudException("The source of the file has not been specified");
}
if (logger != null) {
logger.logInfo("Downloading File [" + source.toString() + "] to [" + destination.getName() + "]");
}
try (InputStream in = source.openStream()) {
Files.copy(in, destination.toPath(), StandardCopyOption.REPLACE_EXISTING);
} catch (IOException exception) {
throw new MbedCloudException("The file could not be downloaded", exception);
}
downloaded = true;
}
private void checkParameters() throws MbedCloudException {
if (downloaded) {
throw new MbedCloudException("The file has already been downloaded");
}
if (destination == null) {
throw new MbedCloudException("The destination of the download has not been specified");
}
if (destination.exists()) {
if (!destination.isFile()) {
throw new MbedCloudException("The destination does not correspond to a file");
}
if (logger != null) {
logger.logWarn("File [" + destination.getName() + "] will be overwritten");
}
}
}
private static File generateFileDestination(String destinationDirectory,
String fileName) throws MbedCloudException {
if (destinationDirectory == null || destinationDirectory.isEmpty()) {
return generateTempFile(fileName, null);
}
final File directory = new File(destinationDirectory);
final File destination = new File(directory, fileName);
if (directory.exists()) {
if (directory.isDirectory()) {
return destination;
}
// In this case, the file path is complete.
return directory;
}
return hasExtension(destinationDirectory) ? directory : destination;
}
private static File generateTempFile(URL source, String extension) throws MbedCloudException {
try {
final String fileName = source == null ? null : Paths.get(source.toURI().getPath()).toFile().getName();
return generateTempFile(fileName, extension);
} catch (URISyntaxException exception) {
throw new MbedCloudException(exception);
}
}
private static File generateTempFile(String fileName, String extension) throws MbedCloudException {
final String finalFileName = fileName == null ? UNDEFINED_DESTINATION_FILENAME : fileName;
try {
return File.createTempFile(getFileNameWithoutExtension(finalFileName),
extension == null ? EXTENSION_SEPARATOR + getFileExtension(finalFileName) : extension);
} catch (IOException exception) {
throw new MbedCloudException(exception);
}
}
protected static boolean hasExtension(String fileName) {
return !getFileExtension(fileName).isEmpty();
}
protected static String getFileExtension(String fileName) {
if (fileName == null || fileName.trim().endsWith(EXTENSION_SEPARATOR)) {
return EMPTY_STRING;
}
final int i = fileName.lastIndexOf('.');
if (i < 0) {
return EMPTY_STRING;
}
final StringBuilder builder = new StringBuilder();
final String shorterFilename = fileName.substring(0, i);
final int j = shorterFilename.lastIndexOf('.');
// This is an arbitrary constraint on the length of the extension.
if (j > 0 && shorterFilename.length() - j < 5) {
builder.append(shorterFilename.substring(j + 1)).append('.');
}
builder.append(fileName.substring(i + 1));
return builder.toString().trim();
}
protected static String getFileNameWithoutExtension(String fileName) {
if (fileName == null) {
return EMPTY_STRING;
}
return fileName.trim().replace(EXTENSION_SEPARATOR + getFileExtension(fileName), EMPTY_STRING);
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "FileDownload [source=" + source + ", destination=" + destination + ", downloaded=" + downloaded + "]";
}
}