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Provide log if the two files are identical and has same contents in Java

I have below code where i am reading the file from particular directory, processing it and once processed i am moving the file to archive directory. This is working fine. I am receiving new file everyday and i am using Control-M scheduler job to run this process.
Now in next run i am reading the new file from that particularly directory again and checking this file with the file in the archive directory and if the content is different then only process the file else dont do anything. There is shell script written to do this job and we dont see any log for this process.
Now i want to produce log message in my java code if the files are identical from the particular directory and in the archive directory then generate log that 'files are identical'. But i dont know exactly how to do this. I dont want to write the the logic to process or move anything in the file ..i just need to check the files are equal and if it is then
produce log message. The file which i recieve are not very big and the max size can be till 10MB.
Below is my code:
for(Path inputFile : pathsToProcess) {
// read in the file:
readFile(inputFile.toAbsolutePath().toString());
// move the file away into the archive:
Path archiveDir = Paths.get(applicationContext.getEnvironment().getProperty(".archive.dir"));
Files.move(inputFile, archiveDir.resolve(inputFile.getFileName()),StandardCopyOption.REPLACE_EXISTING);
}
return true;
}
private void readFile(String inputFile) throws IOException, FileNotFoundException {
log.info("Import " + inputFile);
try (InputStream is = new FileInputStream(inputFile);
Reader underlyingReader = inputFile.endsWith("gz")
? new InputStreamReader(new GZIPInputStream(is), DEFAULT_CHARSET)
: new InputStreamReader(is, DEFAULT_CHARSET);
BufferedReader reader = new BufferedReader(underlyingReader)) {
if (isPxFile(inputFile)) {
Importer.processField(reader, tablenameFromFilename(inputFile));
} else {
Importer.processFile(reader, tablenameFromFilename(inputFile));
}
}
log.info("Import Complete");
}
}

Based on the limited information about the size of file or performance needs, something like this can be done. This may not be 100% optimized, but just an example. You may also have to do some exception handling in the main method, since the new method might throw an IOException:
import org.apache.commons.io.FileUtils; // Add this import statement at the top
// Moved this statement outside the for loop, as it seems there is no need to fetch the archive directory path multiple times.
Path archiveDir = Paths.get(applicationContext.getEnvironment().getProperty("betl..archive.dir"));
for(Path inputFile : pathsToProcess) {
// Added this code
if(checkIfFileMatches(inputFile, archiveDir); {
// Add the logger here.
}
//Added the else condition, so that if the files do not match, only then you read, process in DB and move the file over to the archive.
else {
// read in the file:
readFile(inputFile.toAbsolutePath().toString());
Files.move(inputFile, archiveDir.resolve(inputFile.getFileName()),StandardCopyOption.REPLACE_EXISTING);
}
}
//Added this method to check if the source file and the target file contents are same.
// This will need an import of the FileUtils class. You may change the approach to use any other utility file, or read the data byte by byte and compare. If the files are very large, probably better to use Buffered file reader.
private boolean checkIfFileMatches(Path sourceFilePath, Path targetDirectoryPath) throws IOException {
if (sourceFilePath != null) { // may not need this check
File sourceFile = sourceFilePath.toFile();
String fileName = sourceFile.getName();
File targetFile = new File(targetDirectoryPath + "/" + fileName);
if (targetFile.exists()) {
return FileUtils.contentEquals(sourceFile, targetFile);
}
}
return false;
}

What folder should I store text files?

I have my classes in /src/com.example.myapp/ and I have a text mytext.txt there too.
However, when I reference static File f = new File("mytext.txt")); it does not find it, even though the file is in the same directory as the class.
What do I need to do? What directory is it actually looking in?
Assets is read-only. I need somewhere where I can read and update the text file.

Use an assets folder.
Here is an example...
Loading array from a text file in assets folder (Android)
You create the assets folder in your root project folder then place your file in it. Once it's there, you access this way:
getAssets().open("file.txt");
the getAssets method is part of your Activity / Context. Context carriers a lot of the information about your app.
If you are not in an Activity, you can pass the Context to your class and use this:
context.getAssets().open("file.txt");

If you want the file with EDIT mode, you can use Internal/External Storage
Then you can read it as:
String filePath = context.getFilesDir().getAbsolutePath(); //returns current directory.
File file = new File(filePath, fileName);
try {
BufferedReader br = new BufferedReader(new FileReader(file));
while ((line = br.readLine()) != null) {
text.append(line);
text.append('\n');
}
}
catch (IOException e) {
}
return text.toString(); //the output text from file.
You can even write to this file :
String filename = "myfile";
String string = "ur data";
FileOutputStream outputStream;
try {
outputStream = openFileOutput(filename, Context.MODE_PRIVATE);
outputStream.write(string.getBytes());
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
Hope it will help you ツ

Use the assets directory:
assets/
This is empty. You can use it to store raw asset files. Files that you save here are compiled into an .apk file as-is, and the original filename is preserved. You can navigate this directory in the same way as a typical file system using URIs and read files as a stream of bytes using the AssetManager. For example, this is a good location for textures and game data.

How to store uploaded mulitple pdf file to a specific location in java?

i want to store uploaded file in a specific location in java. if i upload a.pdf then i want it to store this at "/home/rahul/doc/upload/". i went through some questions and answers of stack overflow but i am not satisfied with solutions.
i am working with Play Framework 2.1.2. i am not working with servlet.
i am uploading but it is storing file into temp directory but i want that file store into a folder as not a temp file i want that file like a.pdf in folder not like temp file.
public static Result upload() {
MultipartFormData body = request().body().asMultipartFormData();
FilePart filePart1 = body.getFile("filePart1");
File newFile1 = new File("path in computer");
File file1 = filePart1.getFile();
InputStream isFile1 = new FileInputStream(file1);
byte[] byteFile1 = IOUtils.toByteArray(isFile1);
FileUtils.writeByteArrayToFile(newFile1, byteFile1);
isFile1.close();
}
but i am not satisfied with this solution and i am uploading multiple doc files.
for eg. i upload one doc ab.docx then after upload it is storing temp directory and file is this:
and it's location is this: /tmp/multipartBody5886394566842144137asTemporaryFile
but i want this: /upload/ab.docx
tell me some solution to fix this.

Everything's correct as a last step you need to renameTo the temporary file into your upload folder, you don't need to play around the streams it's as simple as:
public static Result upload() {
Http.MultipartFormData body = request().body().asMultipartFormData();
FilePart upload = body.getFile("picture");
if (upload != null) {
String targetPath = "/your/target/upload-dir/" + upload.getFilename();
upload.getFile().renameTo(new File(targetPath));
return ok("File saved in " + targetPath);
} else {
return badRequest("Something Wrong");
}
}
BTW you should implement some checking if targetPath doesn't exist to prevent errors and/or overwrites. Typical approach is incrementing the file name if file with the same name already exists, for an example sending a.pdf three times should save the files as a.pdf, a_01.pdf, a_02.pdf, etc.

i just completed it. My solution is working fine.
My solution of uploading multiple files is :
public static Result up() throws IOException{
MultipartFormData body = request().body().asMultipartFormData();
List<FilePart> resourceFiles=body.getFiles();
InputStream input;
OutputStream output;
File part1;
String prefix,suffix;
for (FilePart picture:resourceFiles) {
part1 =picture.getFile();
input= new FileInputStream(part1);
prefix = FilenameUtils.getBaseName(picture.getFilename());
suffix = FilenameUtils.getExtension(picture.getFilename());
part1=new File("/home/rahul/Documents/upload",prefix+"."+suffix);
part1.createNewFile();
output = new FileOutputStream(part1);
IOUtils.copy(input, output);
Logger.info("Uploaded file successfully saved in " + part1.getAbsolutePath());
}

How to use a save file dialog from a servlet?

I am trying to let the user save data from my servlet as a CSV file. Originally I was just locating their desktop to drop the file, but permission would be denied with this route so I want to ask the user where they want to save it.
From what I am seeing, I cannot use the Swing API in a servlet because Tomcat does not know how to draw the GUI. I tried this code:
String fileName = "ClassMonitor" + formatter.format(currentDate) + ".csv";
File csvFile = new File(fileName);
//Attempt to write as a CSV file
try{
JFileChooser fileChooser = new JFileChooser();
fileChooser.setSelectedFile(csvFile);
int returnValue = fileChooser.showSaveDialog(null);
if(returnValue == JFileChooser.APPROVE_OPTION)
{
BufferedWriter out = new BufferedWriter(new FileWriter(csvFile));
//Iterates and writes to file
for(ClassInfo classes : csvWrite)
{
//Check if the class has a comma. Currently, only section titles have a comma in them, so that's all we check for.
classes.setSectionTitle(replaceComma(classes.getSectionTitle()));
out.write(classes.toString());
}
//Close the connection
out.close();
}
//Log the process as successful.
logger.info("File was successfully written as a CSV file to the desktop at " + new Date() + "\nFilename" +
"stored as " + fileName + ".");
}
catch(FileNotFoundException ex)
{
//Note the exception
logger.error("ERROR: I/O exception has occurred when an attempt was made to write results as a CSV file at " + new Date());
}
catch(IOException ex)
{
//Note the exception
logger.error("ERROR: Permission was denied to desktop. FileNotFoundException thrown.");
}
catch(Exception ex)
{
//Note the exception
logger.error("ERROR: Save file was not successfull. Ex: " + ex.getMessage());
}
}
But this will throw a headlessException.
Any guidance on how to implement something like a save file dialog in a servlet would be appreciated.

Just write it to the response body instead of to the local(!!) disk file system.
response.setContentType("text/csv"); // Tell browser what content type the response body represents, so that it can associate it with e.g. MS Excel, if necessary.
response.setHeader("Content-Disposition", "attachment; filename=name.csv"); // Force "Save As" dialogue.
response.getWriter().write(csvAsString); // Write CSV file to response. This will be saved in the location specified by the user.
The Content-Disposition: attachment header takes care of the Save As magic.
See also:
JSP generating Excel spreadsheet (XLS) to download

You can't call the JFileChooser from the servlet because the servlet runs on the server, not on the client; all of your Java code is executed on the server. If you want to save the file on the server, you need to already know the path you want to write to.
If you want to prompt the user's browser to save the file, use the content-disposition header: Uses of content-disposition in an HTTP response header

Commons File Upload Not Working In Servlet

I have a servlet which is meant to handle the upload of a very large file. I am trying to use commons fileupload to handle it. Currently, the file I am attempting to upload is 287MB.
I set up the FileItemFactory and ServletFileUpload, then set a very large max file size on the ServletFileUpload.
Unfortunately, when I attempt to create a FileItemIterator, nothing happens. The form is set with the correct action, multipart encoding, and for the POST method.
Can anyone assist? doPost() of the servlet is posted below:
#Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// ensure that the form is multipart encoded since we are uploading a file
if (!ServletFileUpload.isMultipartContent(req)) {
//throw new FileUploadException("Request was not multipart");
log.debug("Request was not multipart. Returning from call");
}
// create a list to hold all of the files
List<File> fileList = new ArrayList<File>();
try {
// setup the factories and file upload stuff
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
upload.setFileSizeMax(999999999);
// create a file item iterator to cycle through all of the files in the req. There SHOULD only be one, though
FileItemIterator iterator = upload.getItemIterator(req);
// iterate through the file items and create a file item stream to output the file
while (iterator.hasNext()) {
// get the file item stream from the iterator
FileItemStream fileItemStream = iterator.next();
// Use the Special InputStream type, passing it the stream and the length of the file
InputStream inputStream = new UploadProgressInputStream(fileItemStream.openStream(), req.getContentLength());
// create a File from the file name
String fileName = fileItemStream.getName(); // this only returns the filename, not the full path
File file = new File(tempDirectory, fileName);
// add the file to the list
fileList.add(file);
// Use commons-io Streams to copy from the inputstrea to a brand-new file
Streams.copy(inputStream, new FileOutputStream(file), true);
// close the inputstream
inputStream.close();
}
} catch (FileUploadException e) {
e.printStackTrace();
}
// now that we've save the file, we can process it.
if (fileList.size() == 0) {
log.debug("No File in the file list. returning.");
return;
}
for (File file : fileList) {
String fileName = file.getName();
BufferedReader reader = new BufferedReader(new FileReader(fileName));
String line = reader.readLine();
List<Feature> featureList = new ArrayList<Feature>(); // arraylist may not be the best choice since I don't know how many features I'm importing
while (!line.isEmpty()) {
String[] splitLine = line.split("|");
Feature feature = new Feature();
feature.setId(Integer.parseInt(splitLine[0]));
feature.setName(splitLine[1]);
feature.setFeatureClass(splitLine[2]);
feature.setLat(Double.parseDouble(splitLine[9]));
feature.setLng(Double.parseDouble(splitLine[10]));
featureList.add(feature);
line = reader.readLine();
}
file.delete(); // todo: check this to ensure it won't blow up the code since we're iterating in a for each
reader.close(); // todo: need this in a finally block somewhere to ensure this always happens.
try {
featureService.persistList(featureList);
} catch (ServiceException e) {
log.debug("Caught Service Exception in FeatureUploadService.", e);
}
}
}

It was an incredibly stupid problem. I left the name attribute off of the FileUpload entry in the GWT UiBinder. Thanks for all of the help from everyone.

Are the only request parameters available File items? Because you may want to put in a check:
if (!fileItemStream.isFormField()){
// then process as file
otherwise you'll get errors. On the surface of things your code looks fine: no errors in the Tomcat logs?

You need to add enctype='multipart/form-data' in html form