I am using apache FTPClient on android. I want to download a file from ftp server. But I want check if it exists on server before downloading. How can I check this?
Thanks,
my code:
public static boolean getFile(String serverName, String userName,
String password, String serverFilePath, String localFilePath)
throws Exception {
FTPClient ftp = new FTPClient();
try {
ftp.connect(serverName);
int reply = ftp.getReplyCode();
if (!FTPReply.isPositiveCompletion(reply)) {
ftp.disconnect();
return false;
}
} catch (IOException e) {
if (ftp.isConnected()) {
try {
ftp.disconnect();
} catch (IOException f) {
throw e;
}
}
throw e;
} catch (Exception e) {
throw e;
}
try {
if (!ftp.login(userName, password)) {
ftp.logout();
}
ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
ftp.enterLocalPassiveMode();
OutputStream output;
output = new FileOutputStream(localFilePath);
ftp.retrieveFile(serverFilePath, output);
output.close();
ftp.noop(); // check that control connection is working OK
ftp.logout();
return true;
} catch (FTPConnectionClosedException e) {
throw e;
} catch (IOException e) {
throw e;
} catch (Exception e) {
throw e;
} finally {
if (ftp.isConnected()) {
try {
ftp.disconnect();
} catch (IOException f) {
throw f;
}
}
}
}
String[] files = ftp.listnames();
look files if desired file name is include...
Assuming ftpClient is an instance of org.apache.commons.net.ftp.FTPClient:
public boolean fileExists(String fileName) throws IOException
{
String[] files = ftpClient.listNames();
return Arrays.asList(files).contains(fileName);
}
When the client sends RETR and the server responds with an error code 550 you can be pretty sure that the file does not exist or you don't have permission to fetch it... Since the FTP spec is a little loose you might just assume for any error in the range 550 - 559 which indicates permanent filesystem error.
InputStream inputStream = ftpClient.retrieveFileStream(filePath);
if (inputStream == null || ftpClient.getReplyCode() == 550) {
// it means that file doesn't exist.
}
or
FTPFile[] mFileArray = ftp.listFiles();
// you can check if array contains needed file
Related
Good day.Im trying to connect to server with socket.Here is my code on how i do it.
private class SocketConnection extends AsyncTask<String, String, String> {
PrintWriter out;
BufferedReader in;
#Override
protected String doInBackground(String... params) {
connect();
try {
out = new PrintWriter(clientSocket.getOutputStream());
in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
} catch (IOException ex) {
System.out.append("error").append("socketcoonection").println();
}
String msg = null;
try {
msg = in.readLine();
} catch (IOException e) {
e.printStackTrace();
}
while (run) {
System.out.append(msg).append("socketcoonection").println();
out.println();
out.flush();
/*try {
msg = in.readLine();
} catch (IOException ex) {
Logger.getLogger(MainActivity.class.getName()).log(Level.SEVERE, null, ex);
}*/
}
return null;
}
}
and here is the connect() method
public void connect() {
try {
clientSocket = new Socket("vaenterprises.org/test.php", 8080);
} catch (UnknownHostException ex) {
} catch (IOException ex) {
}
if (clientSocket != null) {
run = true;
}
}
and this is the server side php code of test.php
echo json_encode("socket working");
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
and the address link is vaenterprises.org/test/php so im trying to connect to it and read the input or output stream or the echo.Whatever i do,i get nullPointerException at System.out.append(msg).append("socketcoonection").println(); and during debug i figured out that its socket which is null...Please tell me what am i doing wrong?
I am planning to create an application for downloading a file from FTP server, Below code has working fine with the functionality, But I need to show current speed and transfer rate while downloading a file, Please help me to solve this problem,
private boolean downloadSingleFile(String remoteFilePath, File downloadFile) {
boolean status = false;
try {
con = new FTPClient();
con.setConnectTimeout(5000);
con.connect(host);
if (con.login(username, password)) {
con.enterLocalPassiveMode(); // important!
con.setFileType(FTP.BINARY_FILE_TYPE);
File parentDir = downloadFile.getParentFile();
if (!parentDir.exists())
parentDir.mkdir();
OutputStream outputStream = null;
try {
outputStream = new BufferedOutputStream(
new FileOutputStream(downloadFile));
con.setFileType(FTP.BINARY_FILE_TYPE);
status = con.retrieveFile(remoteFilePath, outputStream);
} catch (Exception ex) {
Log.e(TAG, ex.getMessage());
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
con.logout();
con.disconnect();
}
} else {
con.logout();
con.disconnect();
// delayWait(duration);
}
}
catch (UnknownHostException e) {
Log.e(TAG, e.getMessage());
} catch (Exception e) {
}
return status;
}
If i would like to download a more than 5Mb or 50 Mb file this requirement will be useful for the user to know about the current speed of the device , Please help me to finish this issues.
Regards
Priya
I'm participating in an online Android course and have (so far) gotten no response on their forum to this issue. I'm using Android Studio on Windows 8.1.
I have the following function to read a file and load an adapter:
private void loadItems() {
BufferedReader reader = null;
try {
FileInputStream fis = openFileInput(FILE_NAME);
reader = new BufferedReader(new InputStreamReader(fis));
String title = null;
String priority = null;
String status = null;
Date date = null;
while (null != (title = reader.readLine())) {
priority = reader.readLine();
status = reader.readLine();
date = ToDoItem.FORMAT.parse(reader.readLine());
mAdapter.add(new ToDoItem(title, Priority.valueOf(priority),
Status.valueOf(status), date));
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} finally {
if (null != reader) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
My questions are:
I don't find the file named by the constant FILE_NAME anywhere on my hard drive. If the file doesn't exist shouldn't openFileInput() throw FileNotFoundException?
Why does InputStreamReader not throw an error?
Via the debugger, I've watched as The logic guarding entry into the WHILE construct happily allows a null value in the title variable to enter the loop. Am I missing something here?
Thanks in advance for any light anyone can shed!!
Markb
I am trying firstly to download the file and its content from Dropbox in Android app using Dropbox Core API but when i execute the following code the app crushes.
EDIT: I have used two functions downloadDropboxFile and copy functions. The problem is that i am getting blank data when i read the local file which is supposed to contain the dropbox file data.
Here is the code where i call the function
downloadDropboxFile("/userandpass.txt");
if (mDBApi.getSession().isLinked())
{
InputStream instream = new FileInputStream(String.valueOf(getExternalCacheDir()) + "/userandpass.txt");
InputStreamReader inputreader = new InputStreamReader(instream);
BufferedReader buffreader = new BufferedReader(inputreader);
mTestOutput.setText(buffreader.readLine());
}
Here is the functions
private boolean downloadDropboxFile(String fileSelected) {
File dir = new File(String.valueOf(getExternalCacheDir()));
if (!dir.exists())
dir.mkdirs();
try {
File localFile = new File(dir + fileSelected);
if (!localFile.exists()) {
localFile.createNewFile();
copy(fileSelected, localFile);
} else {
}
} catch (IOException e) {
e.printStackTrace();
}
return true;
}
private void copy(final String dbPath, final File localFile) {
new Thread(new Runnable() {
#Override
public void run() {
BufferedInputStream br = null;
BufferedOutputStream bw = null;
try {
DropboxAPI.DropboxInputStream fd = mDBApi.getFileStream(dbPath,null);
br = new BufferedInputStream(fd);
bw = new BufferedOutputStream(new FileOutputStream(localFile));
byte[] buffer = new byte[4096];
int read;
while (true) {
read = br.read(buffer);
if (read <= 0) {
break;
}
bw.write(buffer, 0, read);
}
} catch (DropboxException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (bw != null) {
try {
bw.close();
if (br != null) {
br.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}). start();
}
Dropbox Core API Implementation on Android Studio:
On app/libs i have the:
dropbox-android-sdk-1.6.3.jar
httpmime--4.0.3.jar
json_simple-1.1.jar
Your issue is here :
if (!localFile.exists()) {
localFile.createNewFile(); //otherwise dropbox client will fail silently
}
The exception is :
java.io.IOException: open failed: EROFS (Read-only file system)
This means you're trying to create a File on a location that is read only in the phone's memory, I'm guessing the internal storage. Have a look at this excellent answer by Mark Murphy on creating a File based on locations that can be written to.
Hoping this has been of some help, happy coding ;-)
I am using RetrieveFilestream method with BufferedInputStream in a for loop. I am closing all
streams after processing each file and also adding ftp complete pending command.
Every thing works as expected in my test environment with few files. But in realtime data where there are 200-300 files, it hangs somewhere.
It is not throwing any exception making it difficult to debug. Cannot debug one by one. Any help?
Here is my code Block.
public String LoopThroughFiles(FTPClient myftp, String DirectoryName)
{
boolean flag=false;
String output="";
InputStream inStream=null;
BufferedInputStream bInf= null;
StringBuilder mystring = new StringBuilder();
progressBar = (ProgressBar) findViewById(R.id.progressBar);
try {
flag= myftp.changeWorkingDirectory(DirectoryName);
if(flag==true)
{
FTPFile[] files = myftp.listFiles();
progressBar.setMax(files.length);
String fname="";
myftp.enterLocalPassiveMode();
if(files.length > 0)
{
int n=0;
for (FTPFile file : files)
{
n=n+1;
int r= progressBar.getProgress();
progressBar.setProgress(r+n);
fname=file.getName();
// String path= myftp.printWorkingDirectory();
if(fname.indexOf("txt") != -1)
{
inStream = myftp.retrieveFileStream(fname);
int reply = myftp.getReplyCode();
if (inStream == null || (!FTPReply.isPositivePreliminary(reply) && !FTPReply.isPositiveCompletion(reply))) {Log.e("error retrieving file",myftp.getReplyString()); }
bInf=new BufferedInputStream (inStream);
int bytesRead;
byte[] buffer=new byte[1024];
String fileContent=null;
while((bytesRead=bInf.read(buffer))!=-1)
{
fileContent=new String(buffer,0,bytesRead);
mystring.append(fileContent);
}
mystring.append(",");
bInf.close();
inStream.close();
boolean isSucess= myftp.completePendingCommand();
if(isSucess == false)
Log.e("error retrieving file","Failed to retrieve the stream for " + fname);
}
}
flag= myftp.changeToParentDirectory();
}
}
}
catch (java.net.UnknownHostException e) {
e.printStackTrace();
Log.e("readfile,UnknownHost",e.getMessage());
}
catch (java.io.IOException e) {
e.printStackTrace();
Log.e("readfile,IO",e.getMessage());
}
catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("readfile,General",e.getMessage());
}
finally
{
try {
output = mystring.toString();
if(bInf != null)
bInf.close();
if(inStream != null)
inStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("readfile,finallyblock",e.getMessage());
}
}
return output;
}