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Synchronization and/or mutual exclusion for storage class in services

I need to concurrently read and write a common file with different jobIntentServices in my APP. One service (producer) writes data in the file, while another service (consumer) checks if there is data in the shared file. If there is data, it sends it and, if the data transfer was successful, it deletes the file. I have created the following storage controller class:
public class Storage {
private static final String TAG = "Storage";
public void writeToFile(String filePath, String data, Context context) {
try {
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(context.openFileOutput(filePath, Context.MODE_PRIVATE));
outputStreamWriter.write(data);
outputStreamWriter.close();
}
catch (IOException e) {
Log.e(TAG, "File write failed: " + e.toString());
}
}
public String readFromFile(String filePath, Context context) {
String ret = "";
try {
InputStream inputStream = context.openFileInput(filePath);
if ( inputStream != null ) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
String receiveString = "";
StringBuilder stringBuilder = new StringBuilder();
while ( (receiveString = bufferedReader.readLine()) != null ) {
stringBuilder.append("\n").append(receiveString);
}
inputStream.close();
ret = stringBuilder.toString();
}
}
catch (FileNotFoundException e) {
Log.e(TAG, "File not found: " + e.toString());
} catch (IOException e) {
Log.e(TAG, "Can not read file: " + e.toString());
}
return ret;
}
public boolean fileExists(String filename, Context context) {
File file = context.getFileStreamPath(filename);
if(file == null || !file.exists()) {
return false;
}
return true;
}
public boolean deleteFile(String filename, Context context){
File file = context.getFileStreamPath(filename);
return file.delete();
}
The class isn't singleton.

I solved it with a singleton class and using locks:
Lock lockDeviceData = new ReentrantLock();

How to close and delete file in Java

I have written code that should be saved file in the local directory, create zip of that file, send email and delete both files (original and zip), So this is my code:
Method wich send email
public void sendEmail(Properties emailProperties, InputStream inputStream, HttpServletRequest request) throws UnsupportedEncodingException {
MimeMessage mimeMessage = mailSender.createMimeMessage();
try {
MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage, true);
try {
mimeMessageHelper.setFrom(from, personal);
} catch (UnsupportedEncodingException e) {
LOGGER.error(e.getMessage());
throw new SequelException(e.getMessage());
}
mimeMessageHelper.setTo(recipients);
mimeMessageHelper.setSubject(emailProperties.getProperty(PARAM_TITLE));
String message = emailProperties.getProperty(PARAM_EMLMSG);
mimeMessageHelper.setText(message);
InputStreamSource inputStreamSource = null;
if (inputStream != null) {
inputStreamSource = new ByteArrayResource(IOUtils.toByteArray(inputStream));
}
String compressType = COMPRESS_TYPE_ZIP;
String fileName = getAttachFilenameExtension(object, format);
Path filePath = Paths.get(StrUtils.getProperty("temp.email.files.path") + "\\" + fileName);
tempFile = saveTempFile(inputStreamSource.getInputStream(), filePath);
if (tempFile.length() > 0) {
inputStreamSource = compressFile(tempFile, filePath.toString(), compressType);
fileName = StringUtils.substring(fileName, 0, StringUtils.lastIndexOf(fileName, ".")+1) + compressType;
}
mimeMessageHelper.addAttachment(fileName, inputStreamSource);
mailSender.send(mimeMessage);
} catch (MessagingException | IOException e) {
LOGGER.error(e.getMessage());
throw new SequelException(e.getMessage());
} finally {
List<File> files = (List<File>) FileUtils.listFiles(tempFile.getParentFile(), new WildcardFileFilter(
FilenameUtils.removeExtension(tempFile.getName()) + "*"), null);
for (File file : files) {
try {
FileUtils.forceDelete(file);
} catch (IOException e) {
LOGGER.error(e.getMessage());
}
}
}
}
Save file in directory:
private File saveTempFile(InputStream inputStream, Path filePath) throws IOException {
Files.deleteIfExists(filePath);
Files.copy(inputStream, filePath);
return new File(filePath.toString());
}
Compress file:
private InputStreamSource compressFile(File file, String filePath, String compressType) throws IOException {
InputStream is = ZipFile(file, filePath);
InputStreamSource inputStreamSource = new ByteArrayResource(IOUtils.toByteArray(is));
return inputStreamSource;
}
public InputStream ZipFile(File file, String filePath) {
String zipArchiveFileName = StringUtils.substring(filePath, 0, filePath.lastIndexOf(".") + 1) + COMPRESS_TYPE_ZIP;
try (ZipArchiveOutputStream zipOutput = new ZipArchiveOutputStream(new File(zipArchiveFileName));) {
ZipArchiveEntry entry = new ZipArchiveEntry(StringUtils.overlay(file.getName(), "",
StringUtils.lastIndexOf(file.getName(), "_"), StringUtils.lastIndexOf(file.getName(), ".")));
zipOutput.putArchiveEntry(entry);
try (FileInputStream in = new FileInputStream(file);) {
byte[] b = new byte[1024];
int count = 0;
while ((count = in.read(b)) > 0) {
zipOutput.write(b, 0, count);
}
zipOutput.closeArchiveEntry();
}
InputStream is = new FileInputStream(zipArchiveFileName);
return is;
} catch (IOException e) {
LOGGER.error("An error occurred while trying to compress file to zip", e);
throw new SequelException(e.getMessage());
}
}
So the problem is when I try to delete files but zip file does not delete.
I am using Apache commons compress for zipping.
Can you help what's wrong?

For me this code is working perfectly. After compressing you may be trying to delete it without the extension(for eg .7z here).
public static void main(String[] args) {
File file = new File("C:\\Users\\kh1784\\Desktop\\Remote.7z");
file.delete();
if(!file.exists())
System.out.println("Sucessfully deleted the file");
}
Output:-
Sucessfully deleted the file

Download/Save file that is obtainable directly from the given URL

I have got links like this link, which directly ask for the filename to save with, and start downloading in the browser.
How can I download or save this file programmatically?
I tried with the following method:
static void DownloadFile(String url, String fileName) throws MalformedURLException, IOException
{
url = "http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=DESCRIBE+<"+ url +">&format=text%2Fcsv";
URL link = new URL(url); //The file that you want to download
InputStream in = new BufferedInputStream(link.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[] response = out.toByteArray();
FileOutputStream fos = new FileOutputStream(fileName);
fos.write(response);
fos.close();
System.out.println("Finished");
}
but this save the file having only the first line as ""subject","predicate","object"
" and not the complete file.
EDIT:
As suggested in an answer I tried the following, but that too gave only the first line of the file:
static void DownloadFile(String s_url, String fileName) throws MalformedURLException, IOException
{
s_url = "http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=DESCRIBE+<"+ s_url +">&format=text%2Fcsv";
//url = "http://dbpedia.org/data/Sachin_Tendulkar.rdf";
try {
URL url = new URL(s_url); //The file that you want to download
// read text returned by server
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
PrintWriter out = new PrintWriter(fileName);
String line;
while ((line = in.readLine()) != null) {
out.println(line);
}
in.close();
out.close();
}
catch (MalformedURLException e) {
System.out.println("Malformed URL: " + e.getMessage());
}
catch (IOException e) {
System.out.println("I/O Error: " + e.getMessage());
}
System.out.println("Finished");
}
EDIT:
I tried with Apache FileUtils too, but that too gave only the first line of the file.
static void DownloadFile(String s_url, String fileName) throws MalformedURLException, IOException
{
s_url = "http://dbpedia.org/sparql?default-graph-uri=http%3A%2F%2Fdbpedia.org&query=DESCRIBE+<"+ s_url +">&format=text%2Fcsv";
URL url = new URL(s_url); //The file that you want to download
FileUtils.copyURLToFile(url, new File(fileName));
System.out.println("Finished");
}

if you want to download a file, Apache Commons have just what you are looking for, works great!
org.apache.commons.io.FileUtils.copyURLToFile(new URL("URL")), new File("path/to/file"));
if the url returns text, you can try something like this:
try {
URL url = new URL("http://www.google.com:80/");
// read text returned by server
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
PrintWriter out = new PrintWriter("filename.txt");
String line;
while ((line = in.readLine()) != null) {
out.println(line);
}
in.close();
out.close();
}
catch (MalformedURLException e) {
System.out.println("Malformed URL: " + e.getMessage());
}
catch (IOException e) {
System.out.println("I/O Error: " + e.getMessage());
}

Making Java I / O and change the file to split in java

I'm making a project where using java I / O
I have a file with the following data:
170631|0645| |002014 | 0713056699|000000278500
155414|0606| |002014 | 0913042385|000001220000
000002|0000|0000|00000000000|0000000000000000|000000299512
and the output I want is as follows:
170631
0645
002014
file so that the data will be decreased down
and this is my source code:
public class Tes {
public static void main(String[] args) throws IOException{
File file;
BufferedReader br =null;
FileOutputStream fop = null;
try {
String content = "";
String s;
file = new File("E:/split/OUT/Berhasil.RPT");
fop = new FileOutputStream(file);
br = new BufferedReader(new FileReader("E:/split/11072014/01434.RPT"));
if (!file.exists()) {
file.createNewFile();
}
while ((s = br.readLine()) != null ) {
for (String retVal : s.split("\\|")) {
String data = content.concat(retVal);
System.out.println(data.trim());
byte[] buffer = data.getBytes();
fop.write(buffer);
fop.flush();
fop.close();
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
I want is to generate output as above from the data that has been entered
File Input -> Split -> File Output
thanks :)

I think you forgot to mention what problem are you facing. Just by looking at the code it seems like you are closing the fop(FileOutputStream) every time you are looping while writing the split line. The outputStream should be closed once you have written everything, outside the while loop.
import java.io.*;
public class FileReadWrite {
public static void main(String[] args) {
try {
FileReader inputFileReader = new FileReader(new File("E:/split/11072014/01434.RPT"));
FileWriter outputFileWriter = new FileWriter(new File("E:/split/11072014/Berhasil.RPT"));
BufferedReader bufferedReader = new BufferedReader(inputFileReader);
BufferedWriter bufferedWriter = new BufferedWriter(outputFileWriter);
String line;
while ((line = bufferedReader.readLine()) != null) {
for (String splitItem : line.split("|")) {
bufferedWriter.write(splitItem + "\n");
}
}
bufferedWriter.flush();
bufferedWriter.close();
bufferedReader.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

Read a file from a FTP server but InputStream is always null

I want read files in a directory. I want add in:
List<String> nomi = new ArrayList<String>();
the linestring of file Nomi.txt.
With debug i view correctly the files in links(001.jpg 002.jpg 003.jpg) and ft(Nomi.txt), but in stream i have always null;
InputStream stream = f.retrieveFileStream(/*url_ftp + "/photo/"+ft*/ft);
my complete code is this:
private static abstract class GetLinksTask extends AsyncTask<String, Void, List<String>> {
protected List<String> doInBackground(String... urls) {
List<String> links = new ArrayList<String>();
String ft=null;
BufferedReader reader = null;
List<String> nomi = new ArrayList<String>();
FTPClient f = new FTPClient();
try {
int reply;
f.connect(url_ftp);
f.login(username,password );
reply = f.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) {
f.disconnect();
System.err.println("FTP server refused connection.");
}
FTPListParseEngine engine = f.initiateListParsing("photo");
while (engine.hasNext()) {
FTPFile[] files = engine.getNext(25); // "page size" you want
//FTPFile[] files = engine.getFiles(filter);
for (FTPFile file : files) {
if(file.getName().substring(file.getName().length()-3,file.getName().length()).equals("jpg")){
System.out.println(file.getName());
links.add(file.getName());
}else{
ft=file.getName();
InputStream stream = f.retrieveFileStream(/*url_ftp + "/photo/"+ft*/ft);
reader = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
//nomi.add(reader.readLine());
}
System.out.println(file.getName());
}
//names=nomi;
}
}catch (IOException e) {
e.printStackTrace();
}finally {
if (reader != null)
try {
reader.close();
}catch (IOException logOrIgnore) {
}
}
return links;
}
protected abstract void postExecute(List<String> links);
protected void onPostExecute(List<String> lists) {
postExecute(lists);
}
}
Some tips?
thanks

It is not enough to create a Reader
reader = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
and to close it:
reader.close();
Somewhere, in between, you'll actually have to read the data:
String line;
while( (line = reader.readLine()) != null ){
nomi.add( line );
}

I am explaining the full code of getting inputStream from FTP server and then how to read data from that inputstream. I am assuming, you are using TLS/SSL security layer.
public FTPSClient makeFTPConnection(String vserver, int vport, String vuser, String vpassword) {
LOGGER.debug("ENTRY");
try {
ftpClient = new FTPSClient();
} catch (NoSuchAlgorithmException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
ftpClient.connect(vserver, vport);
ftpClient.login(vuser, vpassword);
ftpClient.execPBSZ(0);
ftpClient.execPROT("P");
ftpClient.changeWorkingDirectory("/");
ftpClient.changeWorkingDirectory("/feeds");
ftpClient.enterLocalPassiveMode();
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
} catch (Exception e) {
LOGGER.error(e.getMessage());
}
/* // int reply=ftpClient.getReply();
String replyStr=ftpClient.getReplyString();
ftpClient.getAuthValue();*/
LOGGER.debug("EXIT");
return ftpClient;
}
Then after making the connection, we will check weather file exist at ftp or not.
public InputStream checkWOFileExistAtFTP(FTPSClient ftpClient, String host,String user, String filePath) throws IOException {
int returnCode;
// filePath="ftp://"+user+"#"+host+"/"+filePath;
InputStream inputStream = ftpClient.retrieveFileStream(filePath);
String dd=ftpClient.getReplyString();
returnCode = ftpClient.getReplyCode();
if (inputStream == null || returnCode == 550) {
return null;
}
return inputStream;
}
Now we already got the inputStream in above method now its time to read data from it.
BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));
System.out.println("Reading file start.");
char[] charBuffer = new char[8 * 1024];
StringBuilder builder = new StringBuilder();
int numCharsRead;
while ((numCharsRead = br.read(charBuffer, 0, charBuffer.length)) != -1) {
builder.append(charBuffer, 0, numCharsRead);
}
//will print all data
system.out.println(builder.toString());