Asynchronous File copy in java - java

I want to know how we can move a file to a different location asynchronously,
basically one of my program is keep on appending data to a temporary file and another is checking its size on exceeding the predefined size of the temporary file it should be copied to a permanent directory and the previous program should keep create a new temporary file and continue writing, in between the data copied should not lost.
I tried to do the same with the following code but some of the data are either misplaced or lost.
import java.io.*;
import org.apache.log4j.Logger;
public class FileSizeMonitor {
static Logger log = Logger.getLogger(FileSizeMonitor.class.getName());
private static final String tempDirectory = "c:\\my-temp-dir";
private static final String tempFileName = tempDirectory + "\\" + "my-temp-file.txt";
void FileMonitor() {
File file = new File(tempFileName);
double bytes = 0;
if (file.exists()) {
bytes = file.length();
if (bytes > 2458.0001) {
int length;
byte[] buffer = new byte[1024];
try {
InputStream inStream = null;
OutputStream outStream = null;
String source = tempFileName;
String target = "C:\\Users\\data";
File sourceFile = new File(source);
String fileName = sourceFile.getName();
File targetFile = new File(target + fileName);
inStream = new FileInputStream(sourceFile);
outStream = new FileOutputStream(targetFile);
log.debug("File size exceded the predefined limit,moving the file data to C:\\Users\\data");
while ((length = inStream.read(buffer)) > 0) {
outStream.write(buffer, 0, length);
}
inStream.close();
outStream.close();
sourceFile.delete();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
}
}

Related

How to release a file in Java GUI without closing

I've created a pretty simple Java GUI to browse/load a zip file on Windows platform to begin unzipping and then do some file checking.
Everything works fine except that I have to close the GUI window in order to delete the zip file that has been opened in the GUI.In my finally block of the unzipping method, I've tried adding the following:
public static String unZip(String path)
{
int count = -1;
String savepath = "";
File file = null;
InputStream is = null;
FileOutputStream fos = null;
BufferedOutputStream bos = null;
savepath = path.substring(0, path.lastIndexOf("\\")) + File.separator; //File saving directory
new File(savepath).mkdir(); //create the saving directory
ZipFile zipFile = null;
String topLevelDirName="";
try
{
zipFile = new ZipFile(path,Charset.forName("gbk")); //Encoding
Enumeration<?> entries = zipFile.entries();
int levelCount=0;
while(entries.hasMoreElements())
{
byte buf[] = new byte[buffer];
ZipEntry entry = (ZipEntry)entries.nextElement();
String filename = entry.getName();
boolean ismkdir = false;
if(filename.lastIndexOf("/") != -1){ //To check if there is a directory
ismkdir = true;
}
filename = savepath + filename;
if(entry.isDirectory()){ //If it is a directory
levelCount++;
file = new File(filename);
file.mkdirs();
if(levelCount==1)
topLevelDirName = filename;
continue;
}
file = new File(filename);
if(!file.exists()){
if(ismkdir){
new File(filename.substring(0, filename.lastIndexOf("/"))).mkdirs();
}
}
file.createNewFile(); //Create the file
is = zipFile.getInputStream(entry);
fos = new FileOutputStream(file);
bos = new BufferedOutputStream(fos, buffer);
while((count = is.read(buf)) > -1)
{
bos.write(buf, 0, count);
}
bos.flush();
bos.close();
fos.close();
is.close();
}
zipFile.close();
}catch(IOException ioe){
ioe.printStackTrace();
}finally{
try{
if(bos != null){
bos.close();
}
if(fos != null) {
fos.close();
}
if(is != null){
is.close();
}
if(zipFile != null){
zipFile.close();
}
}catch(Exception e) {
e.printStackTrace();
}
return topLevelDirName;
}
}
However, I am still not able to delete the zip unless explicitly close the GUI.
Wonder if there is anything to do with the Windows file handle?Thanks in advance.
Java 8 introduced the try-with-resources Statement to make this kind of situation simpler and cleaner.
One of the issues you have is, if any one of the attempts to close the many resources you have open fails, then none of the others will be closed
public static String unZip(String path) throws IOException {
int count = -1;
File sourceFile = new File(path);
String name = sourceFile.getName();
name = name.substring(0, name.lastIndexOf(".zip"));
File sourcePath = new File(sourceFile.getParent(), name);
System.out.println("SavePath = " + sourcePath);
if (!sourcePath.exists() && !sourcePath.mkdirs()) {
throw new IOException("Could not create directory " + sourcePath);
}
String topLevelDirName = "";
try (ZipFile zipFile = new ZipFile(sourceFile)) {
Enumeration<?> entries = zipFile.entries();
int levelCount = 0;
byte buf[] = new byte[1024];
while (entries.hasMoreElements()) {
ZipEntry entry = (ZipEntry) entries.nextElement();
String filename = entry.getName();
File file = new File(sourcePath, filename);
if (entry.isDirectory()) { //If it is a directory
levelCount++;
System.out.println("Make directory " + file);
if (!file.exists() && !file.mkdirs()) {
throw new IOException("Could not create directory " + filename);
}
} else {
System.out.println("Extract to " + file);
try (InputStream is = zipFile.getInputStream(entry);
BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file))) {
while ((count = is.read(buf)) > -1) {
bos.write(buf, 0, count);
}
}
}
}
}
return topLevelDirName;
}
I've update the code slightly to try and make it a little cleaner and simpler and to take advantage of the available APIs

How to copy content from a zip to an Android directory?

Hello everyone.
Ask this question so that they could give me a hand and guide me on my way.
My problem
I want to be able to unzip a zip into a folder or directory on the SD card, but my code has not reached the target. Its error is that it does not decompress or copy any of the files in the destination directory. The zip is located in the resources resource folder.
My code
private boolean copyFile1(String filename1, String outPath1) {
AssetManager assetManager = this.getAssets();
final int CHUNK_SIZE = 1024 * 4;
InputStream in;
OutputStream out;
try {
in = assetManager.open(filename1);
String newFileName = outPath1;
ZipInputStream zipStream = new ZipInputStream(in);
ZipEntry zEntry = null;
while ((zEntry = zipStream.getNextEntry()) != null) {
if (zEntry.isDirectory()) {
} else {
FileOutputStream fout = new FileOutputStream(new File(outPath1));
BufferedOutputStream bufout = new BufferedOutputStream(fout);
byte[] buffer = new byte[CHUNK_SIZE];
int read = 0;
while ((read = zipStream.read(buffer)) != -1) {
bufout.write(buffer, 0, read);
}
zipStream.closeEntry();
bufout.close();
fout.close();
}
}
zipStream.close();
Log.d("Unzip", "Unzipping complete. path : " );
} catch (Exception e) {
Log.e("TAG", e.getMessage());
}
return true;
}
If they realize where I failed in my code or I know otherwise. Please let me know. Thank you

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();
}
}

FileOutputStream creates file even if i check file existance

I'm making simple Client-Server application to make file copies on server.
There is clientside method for sending file to server:
private void makeCopy(Socket clientSock) throws IOException {
File file = new File("D:\\client\\toCopy.bmp");
File dest = new File("D:\\server\\copyFile.bmp");
boolean ifExists = dest.exists();
if(ifExists && !file.isDirectory()){
System.out.println("Copy is already made on server.");
}
else{
fis = new FileInputStream(file);
byte[] buffer = new byte[4096];
while (fis.read(buffer) > 0) {
oos.write(buffer);
}
//fis.close();
oos.close();
}
}
Also there is serverside method for receiving file from client:
public void saveFile(Socket s) throws IOException{
File copy = new File("D:\\server\\fileCopy.bmp");
fos = new FileOutputStream(copy);
File fromServer = new File("D:\\client\\toCopy.bmp");
if(copy.exists() && !copy.isDirectory()){
}
else{
byte[] buffer = new byte[4096];
int filesize = (int)fromServer.length();
int read = 0;
int totalRead = 0;
int remaining = filesize;
while((read = ois.read(buffer, 0, Math.min(buffer.length, remaining))) > 0) {
totalRead += read;
remaining -= read;
System.out.println("read " + totalRead + " bytes.");
fos.write(buffer, 0, read);
}
}
}
The problem is, even if i check file existance it still makes file which I can't open (it has 0 bytes written). Any ideas ?
FileOutputStream creates a file output stream and a file in a file system.
First you should check existence and then create FileOutputStream.
File copy = new File("D:\\server\\fileCopy.bmp");
if(copy.exists() && !copy.isDirectory()){ }
fos = new FileOutputStream(copy);
File fromServer = new File("D:\\client\\toCopy.bmp");

multidownload using java servlets

I want to download multiple files in single zip file using java servlet. I successfully downloaded the zip file containing multiple files (in my web page). but the problem is that files are also downloaded in my server(for ex in my jboss bin folder).
Code:
public void createZipFile(String fileNames,HttpServletResponse response,HttpServletRequest request) {
try {
ZipOutputStream outStream1 = null;
ServletOutputStream outStream=null;
FileInputStream inStream =null;
FileOutputStream fos=null;
InputStream inputStream =null;
int bytesRead = 0;
String zipFileName = "zipFileName.zip";
response.setHeader("Content-Disposition", "attachment;filename=\""+zipFileName+"\"");
response.setHeader("Pragma", "private");
response.addHeader("Cache-Control", "no-transform, max-age=0");
response.setHeader("Accept-Ranges", "bytes");
response.setContentType("application/zip");
//fileNames contains multiple file name.so i want to split and get each file
String[] fileName = fileNames.split(",");
byte[] buffer = new byte[1024];
outStream1 = new ZipOutputStream(new FileOutputStream(zipFileName));
for(int i = 0; i < fileName.length; i++) {
String filePath=audioFile.getAllFiles(fileName[i], Integer.parseInt(userId));
inputStream = new URL("************************server File location***************************").openStream();
String fileNaming = fileName[i];
String[] tempFile = fileNaming.split("\\.");
String tempFileExt=tempFile[1];
String temporaryFile=tempFile[0]+"."+tempFileExt;
fos = new FileOutputStream(temporaryFile);//here is the problem(temporary file created in my server -bin folder.but i dont want this to create)
int length = -1;
while ((length = inputStream.read(buffer)) > -1) {
fos.write(buffer, 0, length);
}
inStream = new FileInputStream(fileName[i]);
outStream1.putNextEntry(new ZipEntry(fileName[i]));
fos.close();
inputStream.close();
while ((bytesRead = inStream.read(buffer)) > 0) {
outStream1.write(buffer, 0, bytesRead);
}
}
inStream.close();
outStream1.closeEntry();
outStream1.close();
int bytesRead1 = 0;
byte[] buff = new byte[1024];
ByteArrayOutputStream bao = new ByteArrayOutputStream();
FileInputStream inStream1 =new FileInputStream(zipFileName);
while ((bytesRead1 = inStream1.read(buff)) != -1)
{
bao.write(buff, 0, bytesRead1);
}
byte[] videoBytes = bao.toByteArray();
response.setContentLength(videoBytes.length);
outStream = response.getOutputStream();
outStream.write(videoBytes);
outStream.flush();
outStream.close();
bao.close();
response.flushBuffer();
} catch (Exception ex) {
ex.printStackTrace();
}
}
For whatever reason, you're copying the files twice. Once, to the file system via inputStream and fos, and the second time to the ZipFile, via inStream and outStream1.
Seems like you can simply remove all of the code related to inputStream and fos, and you won't create the files on your filesystem.

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