Following is the snippet from a servlet that attempts to fetch image from the URL. I have fetched the bytes. Now how do I display the image on the webpage ?
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
URL url = new URL("https://abc/zhdhaG1z_bigger.jpeg");
InputStream stream = new BufferedInputStream(url.openStream());
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte buf[] = new byte[1024];
int n = 0;
while(-1 != (n = stream.read(buf)) ) {
bos.write(buf, 0, n);
}
byte res[] = bos.toByteArray();
} finally {
out.close();
}
You Can Rewrite your code like this...see if this helps
public void doGet(HttpRequest request,HttpResponse response)throws ServletException{
response.setContentType("image/jpeg;charset=UTF-8");
response.addHeader("content-disposition", "inline;filename=Default.jpeg");
try {
URL url = new URL("https://abc/zhdhaG1z_bigger.jpeg");
InputStream stream = new BufferedInputStream(url.openStream());
ByteArrayOutputStream bos = new OutputStream();
byte buf[] = new byte[1024];
int n = 0;
while(-1 != (n = stream.read(buf)) ) {
bos.write(buf, 0, n);
}
}
catch(Exception e){
e.printStackTarce();
}
finally {
out.close();
}
}
Related
I want to upload an image to FTP Server. Currently i am using JDeveloper 12c(12.1.3.0).
My Code:
private static final int BUFFER_SIZE = 4096;
public String fileUploadMethod(String imagePath){
String ftpUrl = "ftp://";
String host = "http://192.168.0.42";
String user = "XXXXXX";
String pass = "XXXXXX";
String filePath = "783771-1.jpg";
String uploadPath = imagePath;
ftpUrl =ftpUrl + user +":"+ pass+"#"+host+"/"+filePath+";";
System.out.println("Upload URL: " + ftpUrl);
try {
URL url = new URL(ftpUrl);
URLConnection conn = url.openConnection();
OutputStream outputStream = conn.getOutputStream();
FileInputStream inputStream = new FileInputStream(uploadPath);
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
inputStream.close();
outputStream.close();
System.out.println("File uploaded");
return "File uploaded";
} catch (IOException ex) {
ex.printStackTrace();
}
return null;
}
I am getting an error MalFormedURLException i.e. in detail message "unknown protocol:ftp"
Is there any other option to upload an image using JDeveloper.
Any idea regarding this.
Thanks, Siddharth
Your ftpUrl is wrong. Remove http:// in the host variable. Should be ok then
I haven't really tried ftp upload. But I had tried with multipart form upload. As far as I know, MAF doesnt provide Out-Of-Box support for file upload. What I did was essential recreating the HTTP stream for the image upload.
The POC code is attached below. This may be definitely the CRUDEST implementation but I am not sure if there is a better way.
public void doUpload() {
try {
DeviceManager dm = DeviceManagerFactory.getDeviceManager();
String imgData =
dm.getPicture(50, DeviceManager.CAMERA_DESTINATIONTYPE_FILE_URI, DeviceManager.CAMERA_SOURCETYPE_CAMERA,
false, DeviceManager.CAMERA_ENCODINGTYPE_PNG, 0, 0);
imgData = imgData.substring(7, imgData.length());
int start = imgData.lastIndexOf('/');
String fileName = imgData.substring(start+1, imgData.length());
RestServiceAdapter restServiceAdapter = Model.createRestServiceAdapter();
restServiceAdapter.clearRequestProperties();
String requestMethod = RestServiceAdapter.REQUEST_TYPE_POST;
String requestEndPoint = restServiceAdapter.getConnectionEndPoint("serverBaseUrl");
String requestURI = "/workers/100000018080264";
String request = requestEndPoint + requestURI;
HashMap httpHeadersValue = new HashMap();
httpHeadersValue.put("X-ANTICSRF", "TRUE");
httpHeadersValue.put("Connection", "Keep-Alive");
httpHeadersValue.put("content-type","multipart/form-data; boundary=----------------------------4abf1aa47e18");
// Get the connection
HttpConnection connection = restServiceAdapter.getHttpConnection(requestMethod, request, httpHeadersValue);
OutputStream os = connection.openOutputStream();
byte byteBuffer[] = new byte[50];
int len;
//String temp is appended before the image body
String temp = "------------------------------4abf1aa47e18\r\nContent-Disposition: form-data; name=\"file\"; filename=\"" +fileName+ "\"\r\nContent-Type: image/jpeg\r\n\r\n";
InputStream stream = new ByteArrayInputStream(temp.getBytes("UTF-8"));
if (stream != null) {
while ((len = stream.read(byteBuffer)) >= 0) {
os.write(byteBuffer, 0, len);
}
stream.close();
}
FileInputStream in = new FileInputStream(imgData);
if (in != null) {
while ((len = in.read(byteBuffer)) >= 0) {
os.write(byteBuffer, 0, len);
}
in.close();
}
//The below String is appended after the image body
InputStream stream2 =new ByteArrayInputStream("\r\n------------------------------4abf1aa47e18--\r\n".getBytes("UTF-8"));
if (stream2 != null) {
while ((len = stream2.read(byteBuffer)) >= 0) {
os.write(byteBuffer, 0, len);
}
stream2.close();
}
int status = connection.getResponseCode();
InputStream inputStream = restServiceAdapter.getInputStream(connection);
ByteArrayOutputStream incomingBytes = new ByteArrayOutputStream() // get and process the response.
while ((len = inputStream.read(byteBuffer)) >= 0) {
incomingBytes.write(byteBuffer, 0, len);
}
String ret = incomingBytes.toString();
incomingBytes.close();
} catch (Exception e) {
e.printStackTrace();
}
}
I want to return file (read or load) from method and then remove this file.
public File method() {
File f = loadFile();
f.delete();
return f;
}
But when I delete a file, I delete it from disk and then exists only descriptor to non-existing file on return statement. So what is the most effective way for it.
You can't keep the File handle of deleted file, rather you can keep the data in a byte array temporarily, delete the file and then return the byte array
public byte[] method() {
File f =loadFile();
FileInputStream fis = new FileInputStream(f);
byte[] data = new byte[fis.available()];
fis.read(data);
f.delete();
return data;
}
// Edit Aproach 2
FileInputStream input = new FileInputStream(f);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int bytesRead = input.read(buf);
while (bytesRead != -1) {
baos.write(buf, 0, bytesRead);
bytesRead = input.read(buf);
}
baos.flush();
byte[] bytes = baos.toByteArray();
you can construct the file data from byte array
However, my suggestion is to use IOUtils.toByteArray(InputStream input) from Jakarta commons, why do you want re write when already in plate
Assuming you want to return the file to the browser, this is how I did it :
File pdf = new File("file.pdf");
if (pdf.exists()) {
try {
InputStream inputStream = new FileInputStream(pdf);
httpServletResponse.setContentType("application/pdf");
httpServletResponse.addHeader("content-disposition", "inline;filename=file.pdf");
copy(inputStream, httpServletResponse.getOutputStream());
inputStream.close();
pdf.delete();
} catch (Exception e) {
e.printStackTrace();
}
}
private static int copy(InputStream input, OutputStream output) throws IOException {
byte[] buffer = new byte[512];
int count = 0;
int n = 0;
while (-1 != (n = input.read(buffer))) {
output.write(buffer, 0, n);
count += n;
}
return count;
}
I have the following method from which i am trying to update a progressBar as to how far the download has progressed:
private void wget(java.net.URL url, String destination) throws MalformedURLException, IOException {
java.net.URLConnection conn = url.openConnection();
java.io.InputStream in = conn.getInputStream();
File dstfile = new File(destination);
OutputStream out = new FileOutputStream(dstfile);
byte[] buffer = new byte[512];
int length;
int readBytes = 0;
while ((length = in.read(buffer)) > 0) {
out.write(buffer, 0, length);
// Get progress
int contentLength = conn.getContentLength();
if (contentLength != -1) {
//System.out.println((length / contentLength) * 100); ??
UpdateForm.progressBar.setValue(2);
} else {
}
}
in.close();
out.close();
}
However i cannot seem to figure out how to calculate how many % have gone..
Any ideas?
I was trying to save a image from a link in a website I have written this code but this does not work ..plz help me to do this
public void imageshow(String linkText) {
try {
URL url = new URL(linkText);
InputStream in = new BufferedInputStream(url.openStream());
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buf = new byte[4 * 1024];
int n = 0;
while (-1 != (n = in.read(buf))) {
out.write(buf, 0, n);
}
out.close();
in.close();
byte[] response = out.toByteArray();
FileOutputStream fos = new FileOutputStream("C://chart.gif");
fos.write(response);
fos.close();
} catch (Exception e) {
}
}
Taken from here
import java.net.*;
import java.io.*;
public class DownloadFile
{
public static void main(String[] args)
{
try
{
/*
* Get a connection to the URL and start up
* a buffered reader.
*/
long startTime = System.currentTimeMillis();
System.out.println("Connecting to Mura site...\n");
URL url = new URL("http://www.getmura.com/currentversion/");
url.openConnection();
InputStream reader = url.openStream();
/*
* Setup a buffered file writer to write
* out what we read from the website.
*/
FileOutputStream writer = new FileOutputStream("C:/mura-newest.zip");
byte[] buffer = new byte[153600];
int totalBytesRead = 0;
int bytesRead = 0;
System.out.println("Reading ZIP file 150KB blocks at a time.\n");
while ((bytesRead = reader.read(buffer)) > 0)
{
writer.write(buffer, 0, bytesRead);
buffer = new byte[153600];
totalBytesRead += bytesRead;
}
long endTime = System.currentTimeMillis();
System.out.println("Done. " + (new Integer(totalBytesRead).toString()) + " bytes read (" + (new Long(endTime - startTime).toString()) + " millseconds).\n");
writer.close();
reader.close();
}
catch (MalformedURLException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
URL url = new URL("http://localhost:8080/Work/images/abt.jpg");
InputStream in = new BufferedInputStream(url.openStream());
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int n=0;
while (-1!=(n=in.read(buf)))
{
out.write(buf, 0, n);
}
out.close();
in.close();
byte[] response1 = out.toByteArray();
FileOutputStream fos = new FileOutputStream("C://abt.jpg");
fos.write(response1);
fos.close();
in this code there is some error in last 3 lines
SEVERE: Servlet.service() for servlet ImageDownloadServlet threw exception java.io.FileNotFoundException: C:/abt.jpg (No such file or directory)
How can I solve it?
String filePath = request.getParameter("action");
System.out.println(filePath);
// URL url = new
// URL("http://localhost:8080/Works/images/abt.jpg");
response.setContentType("image/jpeg");
response.setHeader("Content-Disposition", "attachment; filename=icon" + ".jpg");
URL url = new URL(filePath);
URLConnection connection = url.openConnection();
InputStream stream = connection.getInputStream();
BufferedOutputStream outs = new BufferedOutputStream(response.getOutputStream());
int len;
byte[] buf = new byte[1024];
while ((len = stream.read(buf)) > 0) {
outs.write(buf, 0, len);
}
outs.close();
}
Try using File.pathSeparator instead of slash.
maybe try switching C:/abt.jpg to C:\\abt.jpg
("C://abt.jpg");
try reversing the slashes
("C:\\abt.jpg");
I looked up a example link to a FOS to C drive example, and the demo had them the other way.
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
IOException, MalformedURLException {
String filePath = request.getParameter("action");
// String filename = "abt.jpg";
System.out.println(filePath);
URL url = new URL("http://localhost:8080/Works/images/abt.jpg");
InputStream in = new BufferedInputStream(url.openStream());
ByteArrayOutputStream out = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int n = 0;
while (-1 != (n = in.read(buf))) {
out.write(buf, 0, n);
}
out.close();
in.close();
byte[] response1 = out.toByteArray();
FileOutputStream fos = new FileOutputStream("/home/user/Downloads/abt.jpg");
fos.write(response1);
fos.close();
}
this image will be in download folder