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I'm trying to import images from Internet using Java (IDE IntelliJ) but I don't know how to select an image (in this case the first of the row) from google images.
For example I tried to search the capital of Rome and Napoli, but the code can't find any image from images google's section.
Probably you don't understand much what I said, so below you will find the code I wrote with the relative error
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
public class Main{
public static void main(String[] args) {
String[] listaCapitali = {
"Roma",
"Napoli",
};
for (String capitale : listaCapitali) {
ricercaGoogle("https://www.google.com/search?q=" + capitale + "+cartina&source=lnms&tbm=isch&sa=X&ved=2ahUKEwj-moK1y-D0AhXIzaQKHeXUBLUQ_AUoAXoECAEQAw&cshid=1639392166213289&biw=2240&bih=1082&dpr=2");
}
}
private static void ricercaGoogle(String urlPath) {
try {
URL url = new URL(urlPath);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
int response = connection.getResponseCode();
System.out.println(response);
BufferedImage image = ImageIO.read(url);
FileOutputStream fos = new FileOutputStream(String.valueOf(image));
fos.write(response);
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
The error says:
403
javax.imageio.IIOException: Can't read input file!
at java.desktop/javax.imageio.ImageIO.read(ImageIO.java:1308)
at Main.ricercaGoogle(Main.java:33)
at Main.main(Main.java:19)
403
javax.imageio.IIOException: Can't read input file!
at java.desktop/javax.imageio.ImageIO.read(ImageIO.java:1308)
at Main.ricercaGoogle(Main.java:33)
at Main.main(Main.java:19)
Could you also help me to download those images on my computer named with the capital name? Thanks a lot
First thing to do :Your URL is not an URL of an Image ! try to change the URL
You can inspire from that code it works fine :
Get an image from a HTTPGET and Put it on a file
new Thread(new Runnable() {
#Override
public void run() {
HttpClient httpclient = HttpClients.createDefault();
/*
* put your urlPath here instead of http://localhost...
*/
HttpGet httpget = new HttpGet("http://localhost:9090/imageFilm/1");
// Execute and get the response.
HttpResponse response = null;
try {
response = httpclient.execute(httpget);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
HttpEntity entity = response.getEntity();
if (entity != null) {
try (InputStream instream = entity.getContent()) {
// receiving an image and write it within a file
try (FileOutputStream outputStream = new FileOutputStream(
/*
* here i create a file with the image received from the httpGet , you can do other things
*/
new File("C:\\Users\\OUSSAMA\\Desktop\\xc.png"), false)) {
int read;
byte[] bytes = new byte[1024];
while ((read = instream.read(bytes)) != -1) {
outputStream.write(bytes, 0, read);
}
}
} catch (UnsupportedOperationException | IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}).start();
Apache HttpClient dependency needed :
https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient/4.5.13
All The code in one class :
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClients;
public class Main{
public static void main(String[] args) {
String[] listaCapitali = {
"Roma",
"Napoli",
};
for (String capitale : listaCapitali) {
//ricercaGoogle("https://www.google.com/search?q=" + capitale + "+cartina&source=lnms&tbm=isch&sa=X&ved=2ahUKEwj-moK1y-D0AhXIzaQKHeXUBLUQ_AUoAXoECAEQAw&cshid=1639392166213289&biw=2240&bih=1082&dpr=2");//Your URL is not an URL of an Image ; you must change it !
ricercaGoogle("https://i.pinimg.com/originals/1b/75/84/1b758419a811ae05ad4da61acdb7ce22.jpg");
}
}
private static void ricercaGoogle(String urlPath) {
HttpClient httpclient = HttpClients.createDefault();
/*
* put your urlPath here instead of http://localhost...
*/
HttpGet httpget = new HttpGet(urlPath);
// Execute and get the response.
HttpResponse response = null;
try {
response = httpclient.execute(httpget);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
HttpEntity entity = response.getEntity();
if (entity != null) {
try (InputStream instream = entity.getContent()) {
// receiving an image and write it within a file
try (FileOutputStream outputStream = new FileOutputStream(
/*
* here i create a file with the image received from the httpGet , you can do other things
*/
new File("C:\\Users\\Mourad\\Desktop\\xc.png"), false)) {
int read;
byte[] bytes = new byte[1024];
while ((read = instream.read(bytes)) != -1) {
outputStream.write(bytes, 0, read);
}
}
} catch (UnsupportedOperationException | IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
There is an online file (such as http://www.example.com/information.asp) I need to grab and save to a directory. I know there are several methods for grabbing and reading online files (URLs) line-by-line, but is there a way to just download and save the file using Java?
Give Java NIO a try:
URL website = new URL("http://www.website.com/information.asp");
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream("information.html");
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
Using transferFrom() is potentially much more efficient than a simple loop that reads from the source channel and writes to this channel. Many operating systems can transfer bytes directly from the source channel into the filesystem cache without actually copying them.
Check more about it here.
Note: The third parameter in transferFrom is the maximum number of bytes to transfer. Integer.MAX_VALUE will transfer at most 2^31 bytes, Long.MAX_VALUE will allow at most 2^63 bytes (larger than any file in existence).
Use Apache Commons IO. It is just one line of code:
FileUtils.copyURLToFile(URL, File)
Simpler non-blocking I/O usage:
URL website = new URL("http://www.website.com/information.asp");
try (InputStream in = website.openStream()) {
Files.copy(in, target, StandardCopyOption.REPLACE_EXISTING);
}
public void saveUrl(final String filename, final String urlString)
throws MalformedURLException, IOException {
BufferedInputStream in = null;
FileOutputStream fout = null;
try {
in = new BufferedInputStream(new URL(urlString).openStream());
fout = new FileOutputStream(filename);
final byte data[] = new byte[1024];
int count;
while ((count = in.read(data, 0, 1024)) != -1) {
fout.write(data, 0, count);
}
} finally {
if (in != null) {
in.close();
}
if (fout != null) {
fout.close();
}
}
}
You'll need to handle exceptions, probably external to this method.
Here is a concise, readable, JDK-only solution with properly closed resources:
static long download(String url, String fileName) throws IOException {
try (InputStream in = URI.create(url).toURL().openStream()) {
return Files.copy(in, Paths.get(fileName));
}
}
Two lines of code and no dependencies.
Here's a complete file downloader example program with output, error checking, and command line argument checks:
package so.downloader;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.nio.file.Files;
import java.nio.file.Paths;
public class Application {
public static void main(String[] args) throws IOException {
if (2 != args.length) {
System.out.println("USAGE: java -jar so-downloader.jar <source-URL> <target-filename>");
System.exit(1);
}
String sourceUrl = args[0];
String targetFilename = args[1];
long bytesDownloaded = download(sourceUrl, targetFilename);
System.out.println(String.format("Downloaded %d bytes from %s to %s.", bytesDownloaded, sourceUrl, targetFilename));
}
static long download(String url, String fileName) throws IOException {
try (InputStream in = URI.create(url).toURL().openStream()) {
return Files.copy(in, Paths.get(fileName));
}
}
}
As noted in the so-downloader repository README:
To run file download program:
java -jar so-downloader.jar <source-URL> <target-filename>
For example:
java -jar so-downloader.jar https://github.com/JanStureNielsen/so-downloader/archive/main.zip so-downloader-source.zip
Downloading a file requires you to read it. Either way, you will have to go through the file in some way. Instead of line by line, you can just read it by bytes from the stream:
BufferedInputStream in = new BufferedInputStream(new URL("http://www.website.com/information.asp").openStream())
byte data[] = new byte[1024];
int count;
while((count = in.read(data, 0, 1024)) != -1)
{
out.write(data, 0, count);
}
When using Java 7+, use the following method to download a file from the Internet and save it to some directory:
private static Path download(String sourceURL, String targetDirectory) throws IOException
{
URL url = new URL(sourceURL);
String fileName = sourceURL.substring(sourceURL.lastIndexOf('/') + 1, sourceURL.length());
Path targetPath = new File(targetDirectory + File.separator + fileName).toPath();
Files.copy(url.openStream(), targetPath, StandardCopyOption.REPLACE_EXISTING);
return targetPath;
}
Documentation is here.
This answer is almost exactly like the selected answer, but with two enhancements: it's a method and it closes out the FileOutputStream object:
public static void downloadFileFromURL(String urlString, File destination) {
try {
URL website = new URL(urlString);
ReadableByteChannel rbc;
rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream(destination);
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
fos.close();
rbc.close();
} catch (IOException e) {
e.printStackTrace();
}
}
import java.io.*;
import java.net.*;
public class filedown {
public static void download(String address, String localFileName) {
OutputStream out = null;
URLConnection conn = null;
InputStream in = null;
try {
URL url = new URL(address);
out = new BufferedOutputStream(new FileOutputStream(localFileName));
conn = url.openConnection();
in = conn.getInputStream();
byte[] buffer = new byte[1024];
int numRead;
long numWritten = 0;
while ((numRead = in.read(buffer)) != -1) {
out.write(buffer, 0, numRead);
numWritten += numRead;
}
System.out.println(localFileName + "\t" + numWritten);
}
catch (Exception exception) {
exception.printStackTrace();
}
finally {
try {
if (in != null) {
in.close();
}
if (out != null) {
out.close();
}
}
catch (IOException ioe) {
}
}
}
public static void download(String address) {
int lastSlashIndex = address.lastIndexOf('/');
if (lastSlashIndex >= 0 &&
lastSlashIndex < address.length() - 1) {
download(address, (new URL(address)).getFile());
}
else {
System.err.println("Could not figure out local file name for "+address);
}
}
public static void main(String[] args) {
for (int i = 0; i < args.length; i++) {
download(args[i]);
}
}
}
Personally, I've found Apache's HttpClient to be more than capable of everything I've needed to do with regards to this. Here is a great tutorial on using HttpClient
This is another Java 7 variant based on Brian Risk's answer with usage of a try-with statement:
public static void downloadFileFromURL(String urlString, File destination) throws Throwable {
URL website = new URL(urlString);
try(
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream(destination);
) {
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
}
}
There are many elegant and efficient answers here. But the conciseness can make us lose some useful information. In particular, one often does not want to consider a connection error an Exception, and one might want to treat differently some kind of network-related errors - for example, to decide if we should retry the download.
Here's a method that does not throw Exceptions for network errors (only for truly exceptional problems, as malformed url or problems writing to the file)
/**
* Downloads from a (http/https) URL and saves to a file.
* Does not consider a connection error an Exception. Instead it returns:
*
* 0=ok
* 1=connection interrupted, timeout (but something was read)
* 2=not found (FileNotFoundException) (404)
* 3=server error (500...)
* 4=could not connect: connection timeout (no internet?) java.net.SocketTimeoutException
* 5=could not connect: (server down?) java.net.ConnectException
* 6=could not resolve host (bad host, or no internet - no dns)
*
* #param file File to write. Parent directory will be created if necessary
* #param url http/https url to connect
* #param secsConnectTimeout Seconds to wait for connection establishment
* #param secsReadTimeout Read timeout in seconds - trasmission will abort if it freezes more than this
* #return See above
* #throws IOException Only if URL is malformed or if could not create the file
*/
public static int saveUrl(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout) throws IOException {
Files.createDirectories(file.getParent()); // make sure parent dir exists , this can throw exception
URLConnection conn = url.openConnection(); // can throw exception if bad url
if( secsConnectTimeout > 0 ) conn.setConnectTimeout(secsConnectTimeout * 1000);
if( secsReadTimeout > 0 ) conn.setReadTimeout(secsReadTimeout * 1000);
int ret = 0;
boolean somethingRead = false;
try (InputStream is = conn.getInputStream()) {
try (BufferedInputStream in = new BufferedInputStream(is); OutputStream fout = Files
.newOutputStream(file)) {
final byte data[] = new byte[8192];
int count;
while((count = in.read(data)) > 0) {
somethingRead = true;
fout.write(data, 0, count);
}
}
} catch(java.io.IOException e) {
int httpcode = 999;
try {
httpcode = ((HttpURLConnection) conn).getResponseCode();
} catch(Exception ee) {}
if( somethingRead && e instanceof java.net.SocketTimeoutException ) ret = 1;
else if( e instanceof FileNotFoundException && httpcode >= 400 && httpcode < 500 ) ret = 2;
else if( httpcode >= 400 && httpcode < 600 ) ret = 3;
else if( e instanceof java.net.SocketTimeoutException ) ret = 4;
else if( e instanceof java.net.ConnectException ) ret = 5;
else if( e instanceof java.net.UnknownHostException ) ret = 6;
else throw e;
}
return ret;
}
It's possible to download the file with with Apache's HttpComponents instead of Commons IO. This code allows you to download a file in Java according to its URL and save it at the specific destination.
public static boolean saveFile(URL fileURL, String fileSavePath) {
boolean isSucceed = true;
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet(fileURL.toString());
httpGet.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0");
httpGet.addHeader("Referer", "https://www.google.com");
try {
CloseableHttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity fileEntity = httpResponse.getEntity();
if (fileEntity != null) {
FileUtils.copyInputStreamToFile(fileEntity.getContent(), new File(fileSavePath));
}
} catch (IOException e) {
isSucceed = false;
}
httpGet.releaseConnection();
return isSucceed;
}
In contrast to the single line of code:
FileUtils.copyURLToFile(fileURL, new File(fileSavePath),
URLS_FETCH_TIMEOUT, URLS_FETCH_TIMEOUT);
This code will give you more control over a process and let you specify not only time-outs, but User-Agent and Referer values, which are critical for many websites.
Below is the sample code to download a movie from the Internet with Java code:
URL url = new
URL("http://103.66.178.220/ftp/HDD2/Hindi%20Movies/2018/Hichki%202018.mkv");
BufferedInputStream bufferedInputStream = new BufferedInputStream(url.openStream());
FileOutputStream stream = new FileOutputStream("/home/sachin/Desktop/test.mkv");
int count = 0;
byte[] b1 = new byte[100];
while((count = bufferedInputStream.read(b1)) != -1) {
System.out.println("b1:" + b1 + ">>" + count + ">> KB downloaded:" + new File("/home/sachin/Desktop/test.mkv").length()/1024);
stream.write(b1, 0, count);
}
Solution on java.net.http.HttpClient using Authorization:
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.GET()
.header("Accept", "application/json")
// .header("Authorization", "Basic ci5raG9kemhhZXY6NDdiYdfjlmNUM=") if you need
.uri(URI.create("https://jira.google.ru/secure/attachment/234096/screenshot-1.png"))
.build();
HttpResponse<InputStream> response = client.send(request, HttpResponse.BodyHandlers.ofInputStream());
try (InputStream in = response.body()) {
Files.copy(in, Paths.get(target + "screenshot-1.png"), StandardCopyOption.REPLACE_EXISTING);
}
To summarize (and somehow polish and update) previous answers. The three following methods are practically equivalent. (I added explicit timeouts, because I think they are a must. Nobody wants a download to freeze forever when the connection is lost.)
public static void saveUrl1(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout))
throws MalformedURLException, IOException {
// Files.createDirectories(file.getParent()); // Optional, make sure parent directory exists
try (BufferedInputStream in = new BufferedInputStream(
streamFromUrl(url, secsConnectTimeout,secsReadTimeout));
OutputStream fout = Files.newOutputStream(file)) {
final byte data[] = new byte[8192];
int count;
while((count = in.read(data)) > 0)
fout.write(data, 0, count);
}
}
public static void saveUrl2(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout))
throws MalformedURLException, IOException {
// Files.createDirectories(file.getParent()); // Optional, make sure parent directory exists
try (ReadableByteChannel rbc = Channels.newChannel(
streamFromUrl(url, secsConnectTimeout, secsReadTimeout)
);
FileChannel channel = FileChannel.open(file,
StandardOpenOption.CREATE,
StandardOpenOption.TRUNCATE_EXISTING,
StandardOpenOption.WRITE)
) {
channel.transferFrom(rbc, 0, Long.MAX_VALUE);
}
}
public static void saveUrl3(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout))
throws MalformedURLException, IOException {
// Files.createDirectories(file.getParent()); // Optional, make sure parent directory exists
try (InputStream in = streamFromUrl(url, secsConnectTimeout,secsReadTimeout) ) {
Files.copy(in, file, StandardCopyOption.REPLACE_EXISTING);
}
}
public static InputStream streamFromUrl(URL url,int secsConnectTimeout,int secsReadTimeout) throws IOException {
URLConnection conn = url.openConnection();
if(secsConnectTimeout>0)
conn.setConnectTimeout(secsConnectTimeout*1000);
if(secsReadTimeout>0)
conn.setReadTimeout(secsReadTimeout*1000);
return conn.getInputStream();
}
I don't find significant differences, and all seem right to me. They are safe and efficient. (Differences in speed seem hardly relevant - I write 180 MB from the local server to a SSD disk in times that fluctuate around 1.2 to 1.5 secs). They don't require external libraries. All work with arbitrary sizes and (to my experience) HTTP redirections.
Additionally, all throw FileNotFoundException if the resource is not found (error 404, typically), and java.net.UnknownHostException if the DNS resolution failed; other IOException correspond to errors during transmission.
There is a method, U.fetch(url), in the underscore-java library.
File pom.xml:
<dependency>
<groupId>com.github.javadev</groupId>
<artifactId>underscore</artifactId>
<version>1.84</version>
</dependency>
Code example:
import com.github.underscore.U;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
public class Download {
public static void main(String[] args) throws IOException {
Files.write(Paths.get("data.bin"),
U.fetch("https://stackoverflow.com/questions"
+ "/921262/how-to-download-and-save-a-file-from-internet-using-java").blob());
}
}
You can do this in one line using netloader for Java:
new NetFile(new File("my/zips/1.zip"), "https://example.com/example.zip", -1).load(); // Returns true if succeed, otherwise false.
This can read a file on the Internet and write it into a file.
import java.net.URL;
import java.io.FileOutputStream;
import java.io.File;
public class Download {
public static void main(String[] args) throws Exception {
URL url = new URL("https://www.google.com/images/branding/googlelogo/1x/googlelogo_color_272x92dp.png"); // Input URL
FileOutputStream out = new FileOutputStream(new File("out.png")); // Output file
out.write(url.openStream().readAllBytes());
out.close();
}
}
There is an issue with simple usage of:
org.apache.commons.io.FileUtils.copyURLToFile(URL, File)
if you need to download and save very large files, or in general if you need automatic retries in case connection is dropped.
I suggest Apache HttpClient in such cases, along with org.apache.commons.io.FileUtils. For example:
GetMethod method = new GetMethod(resource_url);
try {
int statusCode = client.executeMethod(method);
if (statusCode != HttpStatus.SC_OK) {
logger.error("Get method failed: " + method.getStatusLine());
}
org.apache.commons.io.FileUtils.copyInputStreamToFile(
method.getResponseBodyAsStream(), new File(resource_file));
} catch (HttpException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
method.releaseConnection();
}
First method using the new channel
ReadableByteChannel aq = Channels.newChannel(new url("https//asd/abc.txt").openStream());
FileOutputStream fileOS = new FileOutputStream("C:Users/local/abc.txt")
FileChannel writech = fileOS.getChannel();
Second method using FileUtils
FileUtils.copyURLToFile(new url("https//asd/abc.txt", new local file on system("C":/Users/system/abc.txt"));
Third method using
InputStream xy = new ("https//asd/abc.txt").openStream();
This is how we can download file by using basic Java code and other third-party libraries. These are just for quick reference. Please google with the above keywords to get detailed information and other options.
If you are behind a proxy, you can set the proxies in the Java program as below:
Properties systemSettings = System.getProperties();
systemSettings.put("proxySet", "true");
systemSettings.put("https.proxyHost", "HTTPS proxy of your org");
systemSettings.put("https.proxyPort", "8080");
If you are not behind a proxy, don't include the lines above in your code. Full working code to download a file when you are behind a proxy.
public static void main(String[] args) throws IOException {
String url = "https://raw.githubusercontent.com/bpjoshi/fxservice/master/src/test/java/com/bpjoshi/fxservice/api/TradeControllerTest.java";
OutputStream outStream = null;
URLConnection connection = null;
InputStream is = null;
File targetFile = null;
URL server = null;
// Setting up proxies
Properties systemSettings = System.getProperties();
systemSettings.put("proxySet", "true");
systemSettings.put("https.proxyHost", "HTTPS proxy of my organisation");
systemSettings.put("https.proxyPort", "8080");
// The same way we could also set proxy for HTTP
System.setProperty("java.net.useSystemProxies", "true");
// Code to fetch file
try {
server = new URL(url);
connection = server.openConnection();
is = connection.getInputStream();
byte[] buffer = new byte[is.available()];
is.read(buffer);
targetFile = new File("src/main/resources/targetFile.java");
outStream = new FileOutputStream(targetFile);
outStream.write(buffer);
} catch (MalformedURLException e) {
System.out.println("THE URL IS NOT CORRECT ");
e.printStackTrace();
} catch (IOException e) {
System.out.println("I/O exception");
e.printStackTrace();
}
finally{
if(outStream != null)
outStream.close();
}
}
public class DownloadManager {
static String urls = "[WEBSITE NAME]";
public static void main(String[] args) throws IOException{
URL url = verify(urls);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
InputStream in = null;
String filename = url.getFile();
filename = filename.substring(filename.lastIndexOf('/') + 1);
FileOutputStream out = new FileOutputStream("C:\\Java2_programiranje/Network/DownloadTest1/Project/Output" + File.separator + filename);
in = connection.getInputStream();
int read = -1;
byte[] buffer = new byte[4096];
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
System.out.println("[SYSTEM/INFO]: Downloading file...");
}
in.close();
out.close();
System.out.println("[SYSTEM/INFO]: File Downloaded!");
}
private static URL verify(String url){
if(!url.toLowerCase().startsWith("http://")) {
return null;
}
URL verifyUrl = null;
try{
verifyUrl = new URL(url);
}catch(Exception e){
e.printStackTrace();
}
return verifyUrl;
}
}
There is an online file (such as http://www.example.com/information.asp) I need to grab and save to a directory. I know there are several methods for grabbing and reading online files (URLs) line-by-line, but is there a way to just download and save the file using Java?
Give Java NIO a try:
URL website = new URL("http://www.website.com/information.asp");
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream("information.html");
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
Using transferFrom() is potentially much more efficient than a simple loop that reads from the source channel and writes to this channel. Many operating systems can transfer bytes directly from the source channel into the filesystem cache without actually copying them.
Check more about it here.
Note: The third parameter in transferFrom is the maximum number of bytes to transfer. Integer.MAX_VALUE will transfer at most 2^31 bytes, Long.MAX_VALUE will allow at most 2^63 bytes (larger than any file in existence).
Use Apache Commons IO. It is just one line of code:
FileUtils.copyURLToFile(URL, File)
Simpler non-blocking I/O usage:
URL website = new URL("http://www.website.com/information.asp");
try (InputStream in = website.openStream()) {
Files.copy(in, target, StandardCopyOption.REPLACE_EXISTING);
}
public void saveUrl(final String filename, final String urlString)
throws MalformedURLException, IOException {
BufferedInputStream in = null;
FileOutputStream fout = null;
try {
in = new BufferedInputStream(new URL(urlString).openStream());
fout = new FileOutputStream(filename);
final byte data[] = new byte[1024];
int count;
while ((count = in.read(data, 0, 1024)) != -1) {
fout.write(data, 0, count);
}
} finally {
if (in != null) {
in.close();
}
if (fout != null) {
fout.close();
}
}
}
You'll need to handle exceptions, probably external to this method.
Here is a concise, readable, JDK-only solution with properly closed resources:
static long download(String url, String fileName) throws IOException {
try (InputStream in = URI.create(url).toURL().openStream()) {
return Files.copy(in, Paths.get(fileName));
}
}
Two lines of code and no dependencies.
Here's a complete file downloader example program with output, error checking, and command line argument checks:
package so.downloader;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.nio.file.Files;
import java.nio.file.Paths;
public class Application {
public static void main(String[] args) throws IOException {
if (2 != args.length) {
System.out.println("USAGE: java -jar so-downloader.jar <source-URL> <target-filename>");
System.exit(1);
}
String sourceUrl = args[0];
String targetFilename = args[1];
long bytesDownloaded = download(sourceUrl, targetFilename);
System.out.println(String.format("Downloaded %d bytes from %s to %s.", bytesDownloaded, sourceUrl, targetFilename));
}
static long download(String url, String fileName) throws IOException {
try (InputStream in = URI.create(url).toURL().openStream()) {
return Files.copy(in, Paths.get(fileName));
}
}
}
As noted in the so-downloader repository README:
To run file download program:
java -jar so-downloader.jar <source-URL> <target-filename>
For example:
java -jar so-downloader.jar https://github.com/JanStureNielsen/so-downloader/archive/main.zip so-downloader-source.zip
Downloading a file requires you to read it. Either way, you will have to go through the file in some way. Instead of line by line, you can just read it by bytes from the stream:
BufferedInputStream in = new BufferedInputStream(new URL("http://www.website.com/information.asp").openStream())
byte data[] = new byte[1024];
int count;
while((count = in.read(data, 0, 1024)) != -1)
{
out.write(data, 0, count);
}
When using Java 7+, use the following method to download a file from the Internet and save it to some directory:
private static Path download(String sourceURL, String targetDirectory) throws IOException
{
URL url = new URL(sourceURL);
String fileName = sourceURL.substring(sourceURL.lastIndexOf('/') + 1, sourceURL.length());
Path targetPath = new File(targetDirectory + File.separator + fileName).toPath();
Files.copy(url.openStream(), targetPath, StandardCopyOption.REPLACE_EXISTING);
return targetPath;
}
Documentation is here.
This answer is almost exactly like the selected answer, but with two enhancements: it's a method and it closes out the FileOutputStream object:
public static void downloadFileFromURL(String urlString, File destination) {
try {
URL website = new URL(urlString);
ReadableByteChannel rbc;
rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream(destination);
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
fos.close();
rbc.close();
} catch (IOException e) {
e.printStackTrace();
}
}
import java.io.*;
import java.net.*;
public class filedown {
public static void download(String address, String localFileName) {
OutputStream out = null;
URLConnection conn = null;
InputStream in = null;
try {
URL url = new URL(address);
out = new BufferedOutputStream(new FileOutputStream(localFileName));
conn = url.openConnection();
in = conn.getInputStream();
byte[] buffer = new byte[1024];
int numRead;
long numWritten = 0;
while ((numRead = in.read(buffer)) != -1) {
out.write(buffer, 0, numRead);
numWritten += numRead;
}
System.out.println(localFileName + "\t" + numWritten);
}
catch (Exception exception) {
exception.printStackTrace();
}
finally {
try {
if (in != null) {
in.close();
}
if (out != null) {
out.close();
}
}
catch (IOException ioe) {
}
}
}
public static void download(String address) {
int lastSlashIndex = address.lastIndexOf('/');
if (lastSlashIndex >= 0 &&
lastSlashIndex < address.length() - 1) {
download(address, (new URL(address)).getFile());
}
else {
System.err.println("Could not figure out local file name for "+address);
}
}
public static void main(String[] args) {
for (int i = 0; i < args.length; i++) {
download(args[i]);
}
}
}
Personally, I've found Apache's HttpClient to be more than capable of everything I've needed to do with regards to this. Here is a great tutorial on using HttpClient
This is another Java 7 variant based on Brian Risk's answer with usage of a try-with statement:
public static void downloadFileFromURL(String urlString, File destination) throws Throwable {
URL website = new URL(urlString);
try(
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream(destination);
) {
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
}
}
There are many elegant and efficient answers here. But the conciseness can make us lose some useful information. In particular, one often does not want to consider a connection error an Exception, and one might want to treat differently some kind of network-related errors - for example, to decide if we should retry the download.
Here's a method that does not throw Exceptions for network errors (only for truly exceptional problems, as malformed url or problems writing to the file)
/**
* Downloads from a (http/https) URL and saves to a file.
* Does not consider a connection error an Exception. Instead it returns:
*
* 0=ok
* 1=connection interrupted, timeout (but something was read)
* 2=not found (FileNotFoundException) (404)
* 3=server error (500...)
* 4=could not connect: connection timeout (no internet?) java.net.SocketTimeoutException
* 5=could not connect: (server down?) java.net.ConnectException
* 6=could not resolve host (bad host, or no internet - no dns)
*
* #param file File to write. Parent directory will be created if necessary
* #param url http/https url to connect
* #param secsConnectTimeout Seconds to wait for connection establishment
* #param secsReadTimeout Read timeout in seconds - trasmission will abort if it freezes more than this
* #return See above
* #throws IOException Only if URL is malformed or if could not create the file
*/
public static int saveUrl(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout) throws IOException {
Files.createDirectories(file.getParent()); // make sure parent dir exists , this can throw exception
URLConnection conn = url.openConnection(); // can throw exception if bad url
if( secsConnectTimeout > 0 ) conn.setConnectTimeout(secsConnectTimeout * 1000);
if( secsReadTimeout > 0 ) conn.setReadTimeout(secsReadTimeout * 1000);
int ret = 0;
boolean somethingRead = false;
try (InputStream is = conn.getInputStream()) {
try (BufferedInputStream in = new BufferedInputStream(is); OutputStream fout = Files
.newOutputStream(file)) {
final byte data[] = new byte[8192];
int count;
while((count = in.read(data)) > 0) {
somethingRead = true;
fout.write(data, 0, count);
}
}
} catch(java.io.IOException e) {
int httpcode = 999;
try {
httpcode = ((HttpURLConnection) conn).getResponseCode();
} catch(Exception ee) {}
if( somethingRead && e instanceof java.net.SocketTimeoutException ) ret = 1;
else if( e instanceof FileNotFoundException && httpcode >= 400 && httpcode < 500 ) ret = 2;
else if( httpcode >= 400 && httpcode < 600 ) ret = 3;
else if( e instanceof java.net.SocketTimeoutException ) ret = 4;
else if( e instanceof java.net.ConnectException ) ret = 5;
else if( e instanceof java.net.UnknownHostException ) ret = 6;
else throw e;
}
return ret;
}
It's possible to download the file with with Apache's HttpComponents instead of Commons IO. This code allows you to download a file in Java according to its URL and save it at the specific destination.
public static boolean saveFile(URL fileURL, String fileSavePath) {
boolean isSucceed = true;
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet(fileURL.toString());
httpGet.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:34.0) Gecko/20100101 Firefox/34.0");
httpGet.addHeader("Referer", "https://www.google.com");
try {
CloseableHttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity fileEntity = httpResponse.getEntity();
if (fileEntity != null) {
FileUtils.copyInputStreamToFile(fileEntity.getContent(), new File(fileSavePath));
}
} catch (IOException e) {
isSucceed = false;
}
httpGet.releaseConnection();
return isSucceed;
}
In contrast to the single line of code:
FileUtils.copyURLToFile(fileURL, new File(fileSavePath),
URLS_FETCH_TIMEOUT, URLS_FETCH_TIMEOUT);
This code will give you more control over a process and let you specify not only time-outs, but User-Agent and Referer values, which are critical for many websites.
Below is the sample code to download a movie from the Internet with Java code:
URL url = new
URL("http://103.66.178.220/ftp/HDD2/Hindi%20Movies/2018/Hichki%202018.mkv");
BufferedInputStream bufferedInputStream = new BufferedInputStream(url.openStream());
FileOutputStream stream = new FileOutputStream("/home/sachin/Desktop/test.mkv");
int count = 0;
byte[] b1 = new byte[100];
while((count = bufferedInputStream.read(b1)) != -1) {
System.out.println("b1:" + b1 + ">>" + count + ">> KB downloaded:" + new File("/home/sachin/Desktop/test.mkv").length()/1024);
stream.write(b1, 0, count);
}
Solution on java.net.http.HttpClient using Authorization:
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.GET()
.header("Accept", "application/json")
// .header("Authorization", "Basic ci5raG9kemhhZXY6NDdiYdfjlmNUM=") if you need
.uri(URI.create("https://jira.google.ru/secure/attachment/234096/screenshot-1.png"))
.build();
HttpResponse<InputStream> response = client.send(request, HttpResponse.BodyHandlers.ofInputStream());
try (InputStream in = response.body()) {
Files.copy(in, Paths.get(target + "screenshot-1.png"), StandardCopyOption.REPLACE_EXISTING);
}
To summarize (and somehow polish and update) previous answers. The three following methods are practically equivalent. (I added explicit timeouts, because I think they are a must. Nobody wants a download to freeze forever when the connection is lost.)
public static void saveUrl1(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout))
throws MalformedURLException, IOException {
// Files.createDirectories(file.getParent()); // Optional, make sure parent directory exists
try (BufferedInputStream in = new BufferedInputStream(
streamFromUrl(url, secsConnectTimeout,secsReadTimeout));
OutputStream fout = Files.newOutputStream(file)) {
final byte data[] = new byte[8192];
int count;
while((count = in.read(data)) > 0)
fout.write(data, 0, count);
}
}
public static void saveUrl2(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout))
throws MalformedURLException, IOException {
// Files.createDirectories(file.getParent()); // Optional, make sure parent directory exists
try (ReadableByteChannel rbc = Channels.newChannel(
streamFromUrl(url, secsConnectTimeout, secsReadTimeout)
);
FileChannel channel = FileChannel.open(file,
StandardOpenOption.CREATE,
StandardOpenOption.TRUNCATE_EXISTING,
StandardOpenOption.WRITE)
) {
channel.transferFrom(rbc, 0, Long.MAX_VALUE);
}
}
public static void saveUrl3(final Path file, final URL url,
int secsConnectTimeout, int secsReadTimeout))
throws MalformedURLException, IOException {
// Files.createDirectories(file.getParent()); // Optional, make sure parent directory exists
try (InputStream in = streamFromUrl(url, secsConnectTimeout,secsReadTimeout) ) {
Files.copy(in, file, StandardCopyOption.REPLACE_EXISTING);
}
}
public static InputStream streamFromUrl(URL url,int secsConnectTimeout,int secsReadTimeout) throws IOException {
URLConnection conn = url.openConnection();
if(secsConnectTimeout>0)
conn.setConnectTimeout(secsConnectTimeout*1000);
if(secsReadTimeout>0)
conn.setReadTimeout(secsReadTimeout*1000);
return conn.getInputStream();
}
I don't find significant differences, and all seem right to me. They are safe and efficient. (Differences in speed seem hardly relevant - I write 180 MB from the local server to a SSD disk in times that fluctuate around 1.2 to 1.5 secs). They don't require external libraries. All work with arbitrary sizes and (to my experience) HTTP redirections.
Additionally, all throw FileNotFoundException if the resource is not found (error 404, typically), and java.net.UnknownHostException if the DNS resolution failed; other IOException correspond to errors during transmission.
There is a method, U.fetch(url), in the underscore-java library.
File pom.xml:
<dependency>
<groupId>com.github.javadev</groupId>
<artifactId>underscore</artifactId>
<version>1.84</version>
</dependency>
Code example:
import com.github.underscore.U;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
public class Download {
public static void main(String[] args) throws IOException {
Files.write(Paths.get("data.bin"),
U.fetch("https://stackoverflow.com/questions"
+ "/921262/how-to-download-and-save-a-file-from-internet-using-java").blob());
}
}
You can do this in one line using netloader for Java:
new NetFile(new File("my/zips/1.zip"), "https://example.com/example.zip", -1).load(); // Returns true if succeed, otherwise false.
This can read a file on the Internet and write it into a file.
import java.net.URL;
import java.io.FileOutputStream;
import java.io.File;
public class Download {
public static void main(String[] args) throws Exception {
URL url = new URL("https://www.google.com/images/branding/googlelogo/1x/googlelogo_color_272x92dp.png"); // Input URL
FileOutputStream out = new FileOutputStream(new File("out.png")); // Output file
out.write(url.openStream().readAllBytes());
out.close();
}
}
There is an issue with simple usage of:
org.apache.commons.io.FileUtils.copyURLToFile(URL, File)
if you need to download and save very large files, or in general if you need automatic retries in case connection is dropped.
I suggest Apache HttpClient in such cases, along with org.apache.commons.io.FileUtils. For example:
GetMethod method = new GetMethod(resource_url);
try {
int statusCode = client.executeMethod(method);
if (statusCode != HttpStatus.SC_OK) {
logger.error("Get method failed: " + method.getStatusLine());
}
org.apache.commons.io.FileUtils.copyInputStreamToFile(
method.getResponseBodyAsStream(), new File(resource_file));
} catch (HttpException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
method.releaseConnection();
}
First method using the new channel
ReadableByteChannel aq = Channels.newChannel(new url("https//asd/abc.txt").openStream());
FileOutputStream fileOS = new FileOutputStream("C:Users/local/abc.txt")
FileChannel writech = fileOS.getChannel();
Second method using FileUtils
FileUtils.copyURLToFile(new url("https//asd/abc.txt", new local file on system("C":/Users/system/abc.txt"));
Third method using
InputStream xy = new ("https//asd/abc.txt").openStream();
This is how we can download file by using basic Java code and other third-party libraries. These are just for quick reference. Please google with the above keywords to get detailed information and other options.
If you are behind a proxy, you can set the proxies in the Java program as below:
Properties systemSettings = System.getProperties();
systemSettings.put("proxySet", "true");
systemSettings.put("https.proxyHost", "HTTPS proxy of your org");
systemSettings.put("https.proxyPort", "8080");
If you are not behind a proxy, don't include the lines above in your code. Full working code to download a file when you are behind a proxy.
public static void main(String[] args) throws IOException {
String url = "https://raw.githubusercontent.com/bpjoshi/fxservice/master/src/test/java/com/bpjoshi/fxservice/api/TradeControllerTest.java";
OutputStream outStream = null;
URLConnection connection = null;
InputStream is = null;
File targetFile = null;
URL server = null;
// Setting up proxies
Properties systemSettings = System.getProperties();
systemSettings.put("proxySet", "true");
systemSettings.put("https.proxyHost", "HTTPS proxy of my organisation");
systemSettings.put("https.proxyPort", "8080");
// The same way we could also set proxy for HTTP
System.setProperty("java.net.useSystemProxies", "true");
// Code to fetch file
try {
server = new URL(url);
connection = server.openConnection();
is = connection.getInputStream();
byte[] buffer = new byte[is.available()];
is.read(buffer);
targetFile = new File("src/main/resources/targetFile.java");
outStream = new FileOutputStream(targetFile);
outStream.write(buffer);
} catch (MalformedURLException e) {
System.out.println("THE URL IS NOT CORRECT ");
e.printStackTrace();
} catch (IOException e) {
System.out.println("I/O exception");
e.printStackTrace();
}
finally{
if(outStream != null)
outStream.close();
}
}
public class DownloadManager {
static String urls = "[WEBSITE NAME]";
public static void main(String[] args) throws IOException{
URL url = verify(urls);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
InputStream in = null;
String filename = url.getFile();
filename = filename.substring(filename.lastIndexOf('/') + 1);
FileOutputStream out = new FileOutputStream("C:\\Java2_programiranje/Network/DownloadTest1/Project/Output" + File.separator + filename);
in = connection.getInputStream();
int read = -1;
byte[] buffer = new byte[4096];
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
System.out.println("[SYSTEM/INFO]: Downloading file...");
}
in.close();
out.close();
System.out.println("[SYSTEM/INFO]: File Downloaded!");
}
private static URL verify(String url){
if(!url.toLowerCase().startsWith("http://")) {
return null;
}
URL verifyUrl = null;
try{
verifyUrl = new URL(url);
}catch(Exception e){
e.printStackTrace();
}
return verifyUrl;
}
}
I am uploading file from android to server using HttpUrlConnection. In normal case file upload successful and correct HTTP response code (200) and message captured. But server also validates the file being uploaded and can close connection anytime while uploading which prohibits client to upload unnecessary data to server.
In brief, Server has following validation:
1. File MimeType check:
If file MimeType isn't any image MimeType then close connection immediately throwing HTTP response code 415 and message "Unsupported Media Type". This check done immediately after request arrived in server.
2. File size check:
While upload is being progressed as stream, if file size more then 5 MB then server close connection by throwing HTTP response code 413 and message "Request entity too large"
Current status:
If file is image type AND less then 5 MB upload successful.
If file is not image type OR more then 5 MB unable to get HTTP response code (413 or 415) and message from HttpUrlConnection object. SocketException or IOException occurs and then invoking connection.getResponseCode() throws another exception. Why not connection object holds response code and message sent from server ?
Code:
package com.example.mahbub.fileuploadrnd;
import android.util.Log;
import com.example.mahbub.fileuploadrnd.util.MimeTypesUtil;
import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.SocketException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
public class FileUploadRequest {
private static final String DEBUG_TAG = "FileUploadRequest";
public static final int ERROR_OUT_OF_MEMORY = 0x00;
public static final int ERROR_UNDEFINED = 0x01;
public static final int ERROR_HTTP_ERROR = 0x02;
/**
* The pool of ASCII chars to be used for generating a multipart boundary.
*/
private final static char[] MULTIPART_CHARS =
"-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
private static final String LINE_END = "\r\n";
private static final String TWO_HYPHENS = "--";
String url;
Map<String,String> mStringParts;
String filePartName;
String filePath;
UploadListener mListener;
public FileUploadRequest(String url, String filePartName, String filePath, UploadListener listener) {
this.url = url;
this.mStringParts = new HashMap<>();
this.filePartName = filePartName;
this.filePath = filePath;
this.mListener = listener;
}
public void execute() {
new Thread(new Runnable() {
#Override
public void run() {
executeRequest();
}
}).start();
}
public void addStringPart(String name, String value) {
this.mStringParts.put(name, value);
}
public void addStringParts(Map<String, String> parts) {
this.mStringParts.putAll(parts);
}
public interface UploadListener {
void onSuccess(int responseCode, String response);
void onError(int errorCode);
void transferred(long transferred, double progress);
}
private void executeRequest() {
HttpURLConnection connection = null;
DataOutputStream outputStream = null;
String boundary = generateBoundary();
try {
URL url = new URL(this.url);
connection = (HttpURLConnection) url.openConnection();
// Allow Inputs & Outputs
connection.setDoInput(true);
connection.setDoOutput(true);
connection.setUseCaches(false);
connection.setChunkedStreamingMode(4 * 1024);
// Enable POST method
connection.setRequestMethod("POST");
// Set header field value
connection.setRequestProperty("Connection", "Keep-Alive");
connection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + boundary);
outputStream = new DataOutputStream(connection.getOutputStream());
outputStream.writeBytes(TWO_HYPHENS + boundary + LINE_END);
// At first write all string parts
if(mStringParts.size() > 0) {
for (Map.Entry<String, String> entry : mStringParts.entrySet()) {
//entity.addTextBody(entry.getKey(), entry.getValue());
String partData = String.format("Content-Disposition: form-data; name=\"%s\"", entry.getKey()) + LINE_END + LINE_END;
partData += entry.getValue() + LINE_END;
partData += (TWO_HYPHENS + boundary + LINE_END);
outputStream.writeBytes(partData);
}
}
// Write file data
File file = new File(filePath);
FileInputStream fileInputStream = new FileInputStream(file);
String partData = String.format("Content-Disposition: form-data; name=\"%s\"; filename=\"%s\"", filePartName, file.getName()) + LINE_END;
partData += String.format("Content-Type: %s", getMimeType(file.getName()));
partData += LINE_END + LINE_END;
outputStream.writeBytes(partData);
// Input stream read buffer
byte[] buffer;
// Max possible buffer size
int maxBufferSize = 5 * 1024; // 5KB
// Bytes available to write in input stream
int bytesAvailable = fileInputStream.available();
Log.d(DEBUG_TAG, "File size: " + bytesAvailable);
// Buffer size
int bufferSize = Math.min(bytesAvailable, maxBufferSize);
// Number of bytes read per read operation
int bytesRead;
// Allocate buffer
buffer = new byte[bufferSize];
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
boolean errorOccured = false;
try {
while(bytesRead > 0) {
try {
outputStream.write(buffer, 0, bufferSize);
} catch (OutOfMemoryError e) {
Log.d(DEBUG_TAG, "OutOfMemoryError occurred");
errorOccured = true;
e.printStackTrace();
if(null != mListener) mListener.onError(ERROR_OUT_OF_MEMORY);
break;
} catch (SocketException e) {
Log.d(DEBUG_TAG, "SocketException occurred");
errorOccured = true;
e.printStackTrace();
if(null != mListener) mListener.onError(ERROR_OUT_OF_MEMORY);
break;
} catch (IOException e) {
Log.d(DEBUG_TAG, "IOException occurred");
errorOccured = true;
e.printStackTrace();
if(null != mListener) mListener.onError(ERROR_OUT_OF_MEMORY);
break;
}
bytesAvailable = fileInputStream.available();
bufferSize = Math.min(bytesAvailable, maxBufferSize);
bytesRead = fileInputStream.read(buffer, 0, bufferSize);
double progress = ((double)(file.length()-bytesAvailable) / file.length());
Log.d(DEBUG_TAG, "Progress: " + progress);
if(null != mListener) mListener.transferred(file.length()-bytesAvailable, progress);
}
} catch (Exception e) {
e.printStackTrace();
if(null != mListener) mListener.onError(ERROR_UNDEFINED);
}
if(!errorOccured) {
outputStream.writeBytes(LINE_END);
outputStream.writeBytes(TWO_HYPHENS + boundary + TWO_HYPHENS + LINE_END);
}
// Responses from the server (code and message)
int responseCode = connection.getResponseCode();
String response = connection.getResponseMessage();
Log.d(DEBUG_TAG, "Server Response Code: " + responseCode);
Log.d(DEBUG_TAG, "Server Response Message: " + response);
InputStream inStream = null;
if(responseCode >= 200 && responseCode < 400) inStream = connection.getInputStream();
else inStream = connection.getErrorStream();
String responseString = readStream(inStream);
Log.d(DEBUG_TAG, "responseString: " + responseString);
if(responseCode >= 200 && responseCode < 400) {
if(null != mListener) mListener.onSuccess(responseCode, responseString);
} else {
if(null != mListener) mListener.onError(ERROR_HTTP_ERROR);
}
fileInputStream.close();
outputStream.flush();
outputStream.close();
outputStream = null;
inStream.close();
} catch (Exception e) {
e.printStackTrace();
if(null != mListener) mListener.onError(ERROR_UNDEFINED);
}
}
private String readStream(InputStream iStream) throws IOException {
//build a Stream Reader, it can read char by char
InputStreamReader iStreamReader = new InputStreamReader(iStream);
//build a buffered Reader, so that i can read whole line at once
BufferedReader bReader = new BufferedReader(iStreamReader);
String line = null;
StringBuilder builder = new StringBuilder();
while((line = bReader.readLine()) != null) { //Read till end
builder.append(line);
}
bReader.close(); //close all opened stuff
iStreamReader.close();
//iStream.close(); //EDIT: Let the creator of the stream close it!
// some readers may auto close the inner stream
return builder.toString();
}
private String generateBoundary() {
final StringBuilder buffer = new StringBuilder();
final Random rand = new Random();
final int count = rand.nextInt(11) + 30; // a random size from 30 to 40
for (int i = 0; i < count; i++) {
buffer.append(MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]);
}
return buffer.toString();
}
/**
* Get mimeType based on file extension
* #param fileName
* #return
*/
private String getMimeType(String fileName) {
String[] parts = fileName.split("\\.");
if(parts.length <= 1) return null;
return MimeTypesUtil.getMimeType(parts[parts.length-1]);
}
}
I am trying to make a ftp downloader which would restart from the position where the file was lastly read.
I will be storing some meta-data for this . But while testing i am kicking out the client and also disconnecting the server . But the handle is not getting into the exceptional as indicated in the code:
package fileresumes;
/**
*
* #author agarwall
*/
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Calendar;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPConnectionClosedException;
import org.apache.commons.net.ftp.FTPFile;
public class FileRes {
public static void main(String[] args) {
FTPClient client = new FTPClient();
FileOutputStream fos = null;
int totalBytesRead = 0;
try {
client.connect("localhost");
client.login("anonymous", "");
// The remote filename to be downloaded.
String filename = "testing.txt";
fos = new FileOutputStream(filename);
boolean append = false;
int offset = 0;
long last_modified = 0;
int size = 0;
//long ro = client.getRestartOffset();
//ro = client.getRestartOffset();
//Download file from FTP server;
final File file = new File("C:/users/deadman/Desktop/", "testing.txt");
if (file.exists()) {
last_modified = file.lastModified(); // lastModified() returns the milliseconds since 1970-01-01
append = true;
// Read offset from meta-data file
size = (int) file.length();
offset = size;
}
//Setting the offset to resume download
client.setRestartOffset(offset);
InputStream inputFileStream;
inputFileStream = client.retrieveFileStream("/large.txt");
int bytesRead = 0;
try {
OutputStream out = new FileOutputStream(file, append);
final byte[] bytes = new byte[1024];
while ((bytesRead = inputFileStream.read(bytes)) != -1) {
out.write(bytes, 0, bytesRead);
totalBytesRead += bytesRead;
}
inputFileStream.close();
out.flush();
int get_reply_code = client.getReplyCode();
System.out.println(get_reply_code);
} catch (IOException e) {
// I want my metadata to be updated here .
System.out.println("IOException");
} catch (RuntimeException e) {
// I want my metadata to be updated here .
System.out.println("Runtime Exception ");
} finally {
try {
int get_reply_code = client.getReplyCode();
System.out.println(get_reply_code);
if (fos != null) {
fos.close();
}
client.disconnect();
System.out.println("finish");
} catch (IOException e) {
}
}
} catch (Exception e) {
}
}
}
Can anyone help me in case of broken connection how can we handle the exception here.
I have been trying to do something similar, and so far the only thing I have been able to do is to attempt another command. I haven't gotten to any transfers in coding yet, but for me if I login and there is either a timeout, get kicked, etc, if I try to change folders (or something similar) it throws a FTPConnectionClosedException. I have looked around Google, and have posted a question on here to see if there is a better way, but so far have not heard anything.