How to send zipped http request? - java

I want to send a zipped request body as a POST http request for a web-service based application. Can anybody please help me how can I send a zipped http request or how can i send a zipped request body as part of POST http request?
Edit: Adding the solution here
HttpURLConnection request = null;
StringBuilder sb = new StringBuilder(getFileAsString("TestFile.txt"));
String fileStr = getFileAsString("TestFile.txt");
HttpClient client = new HttpClient();
client.getState().setCredentials(
new AuthScope(hostip, port),
new UsernamePasswordCredentials("username", "password"));
PutMethod post = new PutMethod(url);
post.setRequestHeader("Content-Encoding", "gzip")


HTTP protocol doesn't support compressed requests (it does support compressed responses being exchanged where the client would announce its ability to handle compressed content). If you want to implement compressed requests, then such a protocol should be established between the client and your web-service that the HTTP payload is always compressed so that on the receiving side, the web service can always decompress and interpret the payload.


public static void main(String[] args) throws MessagingException,
IOException {
HttpURLConnection request = null;
try {
// Get the object of DataInputStream
StringBuilder sb = new StringBuilder(getFileAsString("TestFile.txt"));
String fileStr = getFileAsString("TestFile.txt");
System.out.println("FileData=" + sb);
HttpClient client = new HttpClient();
client.getState().setCredentials(
new AuthScope(hostip, portno),
new UsernamePasswordCredentials(username, password));
PutMethod post = new PutMethod(url);
post.setRequestHeader("Content-Encoding", "gzip");
post.setRequestHeader("Content-Type", "application/json");
post.setDoAuthentication(true);
byte b[] = getZippedString(fileStr);;
InputStream bais = new ByteArrayInputStream(b);
post.setRequestBody(bais);
try {
int status = client.executeMethod(post);
} finally {
// release any connection resources used by the method
post.releaseConnection();
}
}catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
}
}


I use a special servlet that decompress and compress the requests and responses
public void doPost(HttpServletRequest req, HttpServletResponse res) throws IOException{
InputStream zipedStreamRequest = req.getInputStream();
String unzipJsonStr = ZipUtil.uncompressWrite(zipedStreamRequest);
System.out.println("<---- ZIP request <----");
System.out.println(unzipJsonStr);
MainHandler handler = new MainHandler();
String responseJson = handler.handle(unzipJsonStr);
System.out.println("----> ZIP response ---->");
System.out.println(responseJson);
OutputStream responseOutputStream = res.getOutputStream();
if (responseJson!=null) {
ZipUtil.compressWrite(responseJson, responseOutputStream);
}
}
then here is my ziputil class
public class ZipUtil {
private static final int NB_BYTE_BLOCK = 1024;
/**
* compress and write in into out
* #param in the stream to be ziped
* #param out the stream where to write
* #throws IOException if a read or write problem occurs
*/
private static void compressWrite(InputStream in, OutputStream out) throws IOException{
DeflaterOutputStream deflaterOutput = new DeflaterOutputStream(out);
int nBytesRead = 1;
byte[] cur = new byte[NB_BYTE_BLOCK];
while (nBytesRead>=0){
nBytesRead = in.read(cur);
byte[] curResized;
if (nBytesRead>0){
if (nBytesRead<NB_BYTE_BLOCK){
curResized = new byte[nBytesRead];
System.arraycopy(cur, 0, curResized, 0, nBytesRead);
} else {
curResized = cur;
}
deflaterOutput.write(curResized);
}
}
deflaterOutput.close();
}
/**
* compress and write the string content into out
* #param in a string, compatible with UTF8 encoding
* #param out an output stream
*/
public static void compressWrite(String in, OutputStream out){
InputStream streamToZip = null;
try {
streamToZip = new ByteArrayInputStream(in.getBytes("UTF-8"));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
try {
ZipUtil.compressWrite(streamToZip, out);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* uncompress and write int into out
* #param in
* #param out
* #throws IOException
*/
private static void uncompressWrite(InputStream in, OutputStream out) throws IOException{
InflaterInputStream inflaterInputStream = new InflaterInputStream(in);
int nBytesRead = 1;
byte[] cur = new byte[NB_BYTE_BLOCK];
while (nBytesRead>=0){
nBytesRead = inflaterInputStream.read(cur);
byte[] curResized;
if (nBytesRead>0){
if (0<=nBytesRead && nBytesRead<NB_BYTE_BLOCK){
curResized = new byte[nBytesRead];
System.arraycopy(cur, 0, curResized, 0, nBytesRead);
} else {
curResized = cur;
}
out.write(curResized);
}
}
out.close();
}
/**
* uncompress and write in into a new string that is returned
* #param in
* #return the string represented the unziped input stream
*/
public static String uncompressWrite(InputStream in){
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
uncompressWrite(in, bos);
} catch (IOException e1) {
e1.printStackTrace();
}
try {
byte[] byteArr = bos.toByteArray();
String out = new String(byteArr, "UTF-8");
return out;
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
return null;
}
}

Related

How to download a file from Internet using Java, with URL query parameters [duplicate]

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;
}
}

how to upload & save pdf file on server with javafx? [duplicate]

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;
}
}

Java proxyservlet post data to another server

I Need to create a java proxyservlet that sends all incoming data (XML) to another Server.
But how do i post my incoming data to the remote Server?
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String server = "http://server.tld";
String subURI = request.getRequestURI().split("/ProxyServlet")[1];
System.out.println("ProxyServlet: " + server + subURI);
URL remoteServer = new URL(server + subURI);
HttpURLConnection connection = (HttpURLConnection) remoteServer.openConnection();
//somehow apply request to remoteServer and receive response
}

As simple as using CloseableHttpClient for newer as Java7 or using HttpClient for too old Java version?
Then read your OutPutStream into Byte Array and write to InputStream of CloseableHttpClient?

Finally i could solve it, with the help of this article:
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String server = "http://server.tld";
String subURI = request.getRequestURI().split("/ProxyServlet")[1];
System.out.println("ProxyServlet: " + server + subURI);
URL remoteServerURL = new URL(server+subURI);
HttpURLConnection remoteServer = (HttpURLConnection) remoteServerURL.openConnection();
remoteServer.setRequestMethod("POST");
remoteServer.setDoOutput(true);
remoteServer.getOutputStream().write(readBytes(request.getInputStream()));
response.getOutputStream().write(readBytes(remoteServer.getInputStream()));
}
/**
* Read and return the entire contents of the supplied {#link InputStream stream}. This method always closes the stream when
* finished reading.
*
* #param stream the stream to the contents; may be null
* #return the contents, or an empty byte array if the supplied reader is null
* #throws IOException if there is an error reading the content
*/
private byte[] readBytes( InputStream stream ) throws IOException {
if (stream == null) return new byte[] {};
byte[] buffer = new byte[1024];
ByteArrayOutputStream output = new ByteArrayOutputStream();
boolean error = false;
try {
int numRead = 0;
while ((numRead = stream.read(buffer)) > -1) {
output.write(buffer, 0, numRead);
}
} catch (IOException e) {
error = true; // this error should be thrown, even if there is an error closing stream
throw e;
} catch (RuntimeException e) {
error = true; // this error should be thrown, even if there is an error closing stream
throw e;
} finally {
try {
stream.close();
} catch (IOException e) {
if (!error) throw e;
}
}
output.flush();
return output.toByteArray();
}

Audio file stream in HTTP Post Jersey using Java

I have been stuck on an issue for the last couple of days and frankly I am out of ideas. What I am trying to do is to host an rest service using Jersey that will accept a post request with stream of audio data in its payload.
Issue I have been running into is that that I loose data consistency (I am running CRC check on both client and server) and after 8 reads of with 1024 bytes buffer CRC between data sent and data received becomes inconsistent. It works just fine when I am dealing with text or content of smaller size. Code is attached, can anyone please tell me what I am doing wrong?
Server:
#POST
#Consumes("audio/wav")
#Produces(MediaType.TEXT_PLAIN)
public String streamCommand(#Context HttpServletRequest request ) throws Exception
{
CRC32 crc = new CRC32();
InputStream stream = request.getInputStream();
byte[] readBuffer = new byte[1024];
StringBuilder builder = new StringBuilder();
while (stream.read(readBuffer) > -1)
{
crc.update(readBuffer);
builder.append(new String(readBuffer));
System.out.println(crc.getValue());
}
return builder.toString();
}
Client:
static final String SOUND_FILE_NAME = "SoundTest.wav";
#BeforeClass
public static void setup() throws Exception
{
soundStream = classloader.getResourceAsStream(SOUND_FILE_NAME);
}
#Test
public void test() throws Exception {
PipedOutputStream stream = new PipedOutputStream();
DataStreamer data = new DataStreamer(stream, soundStream);
ExecutorService executor = Executors.newFixedThreadPool(1);
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost("http://localhost:8080/EVAFrontEnd/webapi/users/1/devices/1/command");
post.addHeader(HttpHeaders.CONTENT_TYPE, "audio/wav");
InputStreamEntity requestEntity = new InputStreamEntity(new PipedInputStream((PipedOutputStream) stream), -1);
post.setEntity(requestEntity);
executor.execute(data);
executor.shutdown();
HttpResponse r = client.execute(post);
assertNotNull(r);
}
Data Streamer:
public class DataStreamer implements Runnable {
OutputStream writeStream;
CheckedInputStream readStream;
static Logger logger = Logger.getLogger(DataStreamer.class);
public DataStreamer(OutputStream stream, InputStream readingStrem) {
this.writeStream = stream;
this.readStream = new CheckedInputStream(readingStrem, new Adler32());
}
#Override
public void run()
{
CRC32 crc = new CRC32();
try {
byte[] buffer = new byte[1024];
while (readStream.read(buffer) > -1) {
crc.update(buffer);
System.out.println(crc.getValue());
writeStream.write(buffer);
}
System.out.println("END CRC");
readStream.close();
writeStream.close();
}
catch (Exception e) {
logger.error("Unable to stream data.", e);
}
}
}
Thank you!

You need to always save the number of bytes written by
bytes_read = readStream.read(buffer);
into a variable, because that method sometimes gives a short result. Then use ArrayList.copyOfRange to create a subarray [0 ... bytes_read-1] from the buffer with only the valid bytes.

How to Mock a javax.servlet.ServletInputStream

I am creating some unit testing and trying to Mock out some calls. Here is what I have in my working code:
String soapRequest = (SimUtil.readInputStream(request.getInputStream())).toString();
if (soapRequest.equals("My String")) { ... }
and SimUtil.readInputSteam looks like this:
StringBuffer sb = new StringBuffer();
BufferedReader reader = null;
try {
reader = new BufferedReader(new InputStreamReader(inputStream));
final int buffSize = 1024;
char[] buf = new char[buffSize];
int numRead = 0;
while ((numRead = reader.read(buf)) != -1) {
String readData = String.valueOf(buf, 0, numRead);
sb.append(readData);
buf = new char[buffSize];
}
} catch (IOException e) {
LOG.error(e.getMessage(), e);
} finally {
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
LOG.error(e.getMessage(), e);
}
}
What I am trying to do is the request.getInputStream(), the stream returns certain String.
HttpServletRequest request = mock(HttpServletRequest.class);
ServletInputStream inputStream = mock(ServletInputStream.class);
when(request.getInputStream()).thenReturn(inputStream);
So This is the code I want to condition
when(inputStream.read()).thenReturn("My String".toInt());
Any Help would be greatly appreciated.

Don't mock the InputStream. Instead, transform the String to an array of bytes using the
getBytes() method. Then create a ByteArrayInputStream with the array as input, so that it returns the String when consumed, each byte at a time. Next, create a ServletInputStream that wraps a regular InputStream like the one from Spring:
public class DelegatingServletInputStream extends ServletInputStream {
private final InputStream sourceStream;
/**
* Create a DelegatingServletInputStream for the given source stream.
* #param sourceStream the source stream (never <code>null</code>)
*/
public DelegatingServletInputStream(InputStream sourceStream) {
Assert.notNull(sourceStream, "Source InputStream must not be null");
this.sourceStream = sourceStream;
}
/**
* Return the underlying source stream (never <code>null</code>).
*/
public final InputStream getSourceStream() {
return this.sourceStream;
}
public int read() throws IOException {
return this.sourceStream.read();
}
public void close() throws IOException {
super.close();
this.sourceStream.close();
}
}
and finally, the HttpServletRequest mock would return this DelegatingServletInputStream object.

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