Develop Reference

Code that download empty file and supposed not to

I have this part of function where it supposed to download file like pdf from server and store in new directory. It does do this but an empty pdf or text file.How to fix it.
`File urlfile = new File(host + "/" + path);
urlfile.getParentFile().mkdirs();
// create outputstream for request and inputstream for data
// download
FileOutputStream outS = new FileOutputStream(urlfile);
DataInputStream instream = new DataInputStream(newsocket.getInputStream());
// get rid of head part to get to actual file
String l = null;
String lastmodtime = null;
boolean done = false;
while (!(l = DAA.readLine()).equals("")) {
if (!done && l.contains("Last-Modified:")) {
lastmodtime = l.substring(l.indexOf(' ') + 1, l.length());
done = true;
System.out.println(l);
}
}
// read in bytes to correct file name
try {
byte[] inbytes = new byte[16384];
int input;
while ((input = instream.read(inbytes)) != -1) {
outS.write(inbytes, 0, input);
}
}`

You can try this simple code if you want to create a copy of the file or you can even use apache commons io (FileUtils.copyFile(source, dest)) for java copy file operation.
private static void copyFileUsingStream(File source, File dest)
throws IOException {
InputStream is = null;
OutputStream os = null;
try {
is = new FileInputStream(source);
os = new FileOutputStream(dest);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer)) > 0) {
os.write(buffer, 0, length);
}
} finally {
is.close();
os.close();
}
}

Java : Writing a String to a JPG File

Alright, so I am writing a small program that should have taken 10 minutes to complete however I am running into unforeseen problems.
The program should take in some old files I had in a vault program on my old phone, they are basically Jpg files but with an added "obscured" text to the front of the file.
So below is my code logic
get a folder input for the files,
create an arraylist containing each actual file.
call ConvertFiles to convert the file to a string,
delete the first 8 characters using substring and save that temp file to another arraylist containing the strings.
decode that string as base64 and input that into a bytearrayinputstream and save that to a bufferedimage.
This is where the problem occurs. I have content all the way up to the ImageIO.read(bis), so when it tries to write to a new file it throws the image == null
from the ImageTypeSpecifier. I have tried multiple ways of decoding and encoding the string, but any help is wanted and if any more information is needed I will provide it!
public class ImageConvert {
private File folder;
private ArrayList<File> files;
private ArrayList<String> stringFiles = new ArrayList<>();
private ArrayList<BufferedImage> bfImages = new ArrayList<>();
boolean isRunning = true;
Scanner scanner = new Scanner(System.in);
String folderPath;
public static void main(String[] args) {
ImageConvert mc = new ImageConvert();
mc.mainCode();
}
public void mainCode(){
System.out.println("Please enter the folder path: ");
folderPath = scanner.nextLine();
folder = new File(folderPath);
//System.out.println("folderpath: " + folder);
files = new ArrayList<File>(Arrays.asList(folder.listFiles()));
convertFiles();
}
public void convertFiles(){
for(int i = 0; i < files.size(); i++){
try {
String temp = FileUtils.readFileToString(files.get(i));
//System.out.println("String " + i + " : " + temp);
stringFiles.add(temp.substring(8));
} catch (IOException ex) {
Logger.getLogger(ImageConvert.class.getName()).log(Level.SEVERE,
null, ex);
}
}
//System.out.println("Converted string 1: " + stringFiles.get(0));
for(int j = 0; j < stringFiles.size(); j++){
BufferedImage image = null;
byte[] imageByte;
try {
BASE64Decoder decoder = new BASE64Decoder();
imageByte = decoder.decodeBuffer(stringFiles.get(j));
System.out.println(imageByte.toString());
ByteArrayInputStream bis = new ByteArrayInputStream(imageByte);
image = ImageIO.read(bis);
bis.close();
bfImages.add(image);
} catch (IOException ex) {
Logger.getLogger(ImageConvert.class.getName()).log(Level.SEVERE,
null, ex);
}
}
System.out.println("Image 1: " + bfImages.get(0));
for(int k = 0; k < bfImages.size(); k++){
try {
ImageIO.write(bfImages.get(k), "jpg",
new File(folderPath + "/" + k + ".jpg"));
} catch (IOException ex) {
Logger.getLogger(ImageConvert.class.getName()).log(Level.SEVERE,
null, ex);
}
}
}
}
This is an example of my files:

The following example uses the file you included with your question. You don't need to do any decoding, just read the file into memory, store the 8 byte String and then write the remaining bytes to a jpg from an 8 byte offset.
Just adapt the method below to work with your: "folder input for files". You don't need an ArrayList containing each actual jpg file.
public void convertFiles() {
File imgFile;
byte[] bytes;
FileOutputStream fos;
String temp;
for (int i = 0; i < files.size(); i++) {
temp = "";
try {
// 'read' method can be found below
bytes = read(files.get(i));
// read the 8 byte string from the beginning of the file
for(int j = 0; j < 8; j++) {
temp += (char) bytes[j];
}
imgFile = new File("img.jpg");
// points to './img.jpg'
fos = new FileOutputStream(imgFile);
// write from offset 8 to end of 'bytes'
fos.write(bytes, 8, bytes.length - 8);
fos.close();
} catch (FileNotFoundException e) {
// Logger stuff
} catch (IOException ex) {
// Logger stuff
}
System.out.println("[temp]:> " + temp);
}
}
read(File file) method adapted from a community wiki answer to File to byte[] in Java
public byte[] read(File file) throws IOException {
ByteArrayOutputStream ous = null;
InputStream ios = null;
try {
byte[] buffer = new byte[4096];
ous = new ByteArrayOutputStream();
ios = new FileInputStream(file);
int read = 0;
while ((read = ios.read(buffer)) != -1) {
ous.write(buffer, 0, read);
}
} finally {
try {
if (ous != null)
ous.close();
} catch (IOException e) {
}
try {
if (ios != null)
ios.close();
} catch (IOException e) {
}
}
return ous.toByteArray();
}
Output:
[temp]:> obscured
Image File:

Exception in thread "Thread-9" java.lang.OutOfMemoryError: Java heap space

I have been writing an updater for my game.
It checks a .version file on drop box and compares it to the local .version file.
If there is any link missing from the local version of the file, it downloads the required link one by one.
This is the error that it shows
Exception in thread "Thread-9" java.lang.OutOfMemoryError: Java heap space
at com.fox.listeners.ButtonListener.readFile(ButtonListener.java:209)
at com.fox.listeners.ButtonListener.readFile(ButtonListener.java:204)
at com.fox.listeners.ButtonListener.UpdateStart(ButtonListener.java:132)
at com.fox.listeners.ButtonListener$1.run(ButtonListener.java:58)
It only shows for some computers though and not all of them this is the readFile method
private byte[] readFile(URL u) throws IOException {
return readFile(u, getFileSize(u));
}
private static byte[] readFile(URL u, int size) throws IOException {
byte[] data = new byte[size];
int index = 0, read = 0;
try {
HttpURLConnection conn = null;
conn = (HttpURLConnection) u.openConnection();
conn.addRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)");
InputStream is = conn.getInputStream();
progress_a = 0;
progress_b = data.length;
while(index < data.length) {
read = is.read(data, index, size-index);
index += read;
progress_a = index;
}
} catch(Exception e) {
e.printStackTrace();
}
return data;
}
private byte[] readFile(File f) {
byte[] data = null;
try {
data = new byte[(int)f.length()];
#SuppressWarnings("resource")
DataInputStream dis = new DataInputStream(new FileInputStream(f));
dis.readFully(data);
} catch (IOException e) {
e.printStackTrace();
}
return data;
}
This is the main method that is ran
public void UpdateStart() {
System.out.println("Starting Updater..");
if(new File(cache_dir).exists() == false) {
System.out.print("Creating cache dir.. ");
while(new File(cache_dir).mkdir() == false);
System.out.println("Done");
}
try {
version_live = new Version(new URL(version_file_live));
} catch(MalformedURLException e) {
e.printStackTrace();
}
version_local = new Version(new File(version_file_local));
Version updates = version_live.differences(version_local);
System.out.println("Updated");
int i = 1;
try {
byte[] b = null, data = null;
FileOutputStream fos = null;
BufferedWriter bw = null;
for(String s : updates.files) {
if(s.equals(""))
continue;
System.out.println("Reading file "+s);
AppFrame.pbar.setString("Downloading file "+ i + " of "+updates.files.size());
if(progress_b > 0) {
s = s + " " +(progress_a * 1000L / progress_b / 10.0)+"%";
}
b = readFile(new URL(s));
progress_a = 0;
progress_b = b.length;
AppFrame.pbar.setString("Unzipping file "+ i++ +" of "+updates.files.size());
ZipInputStream zipStream = new ZipInputStream(new ByteArrayInputStream(b));
File f = null, parent = null;
ZipEntry entry = null;
int read = 0, entry_read = 0;
long entry_size = 0;
progress_b = 0;
while((entry = zipStream.getNextEntry()) != null)
progress_b += entry.getSize();
zipStream = new ZipInputStream(new ByteArrayInputStream(b));
while((entry = zipStream.getNextEntry()) != null) {
f = new File(cache_dir+entry.getName());
if(entry.isDirectory())
continue;
System.out.println("Making file "+f.toString());
parent = f.getParentFile();
if(parent != null && !parent.exists()) {
System.out.println("Trying to create directory "+parent.getAbsolutePath());
while(parent.mkdirs() == false);
}
entry_read = 0;
entry_size = entry.getSize();
data = new byte[1024];
fos = new FileOutputStream(f);
while(entry_read < entry_size) {
read = zipStream.read(data, 0, (int)Math.min(1024, entry_size-entry_read));
entry_read += read;
progress_a += read;
fos.write(data, 0, read);
}
fos.close();
}
bw = new BufferedWriter(new FileWriter(new File(version_file_local), true));
bw.write(s);
bw.newLine();
bw.close();
}
} catch(Exception e) {
e.printStackTrace();
return;
}
System.out.println(version_live);
System.out.println(version_local);
System.out.println(updates);
CacheUpdated = true;
if(CacheUpdated) {
AppFrame.pbar.setString("All Files are downloaded click Launch to play!");
}
}
I don't get why it is working for some of my players and then some of my other players it does not i have been trying to fix this all day and i am just so stumped at this point but this seems like its the only big issue left for me to fix.

Either increase the memory allocated to your JVM (How can I increase the JVM memory?), or make sure that the file being loaded in memory isn't gigantic (if it is, you'll need to find an alternate solution, or just read chunks of it at a time instead of loading the entire thing in memory).

Do your update in several steps. Here's some pseudo-code with Java 8. It's way shorter than what you wrote because Java has a lot of built-in tools that you re-write much less efficiently.
// Download
Path zipDestination = Paths.get(...);
try (InputStream in = source.openStream()) {
Files.copy(in, zipDestination);
}
// Unzip
try (ZipFile zipFile = new ZipFile(zipDestination.toFile())) {
for (ZipEntry e: Collections.list(zipFile.entries())) {
Path entryDestination = Paths.get(...);
Files.copy(zipFile.getInputStream(e), entryDestination);
}
}
// Done.

Upload Image to FTP Server using ADF Mobile Application

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();
}
}

Saving image from a link

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();
}
}
}