Reading content from an ftp file

Hello. I am trying to read a content of file downloaded from ftp and return it as a String. This is what I use:

Code:

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import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.apache.commons.net.ftp.FTPClient;


public class Test {


        public static void main(String [] args) throws IOException        {
                FTPClient ftp = new FTPClient();
                ftp.connect("ftp://tgftp.nws.noaa.gov/data/observations/metar/stations/");
                InputStream in = ftp.retrieveFileStream("KLAS.TXT");
               
                BufferedInputStream inbf = new BufferedInputStream(in);
               
            int bytesRead;
                byte[] buffer=new byte[1024];
                String fileContent=null;
               
                while((bytesRead=inbf.read(buffer))!=-1)
                  {
                      fileContent=new String(buffer,0,bytesRead);
                  }
                 
                  System.out.println("File: " + fileContent);
                }
}

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The code does not work, although all the links are correct. Thanks a lot for your help!

For one thing, you're over-writing the content of the fileContent String with each iteration of the loop. For another, if the data is truly String data, consider wrapping your InputStream in a InputStreamReader and that in a BufferedReader which should make getting text data much easier and more intuitive and less error prone.

Fubarable. Thank you very much! I changed the code based on your suggestion:

Code:

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public static void main(String [] args) throws IOException        {
              FTPClient ftp = new FTPClient();
              InputStream in = ftp.retrieveFileStream("ftp://tgftp.nws.noaa.gov/data/observations/metar/stations/KLAX.TXT");
              InputStreamReader isr = new InputStreamReader(in);
              BufferedReader br = new BufferedReader(isr);
             
              int bytesRead = 0;       
              byte[] buffer=new byte[1024];       
              String fileContent=null;
             
              fileContent=new String(buffer,0,bytesRead);
             
              System.out.println(fileContent);
        }
}

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No, it is not working either:

Code:

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Exception in thread "main" java.lang.NullPointerException
        at org.apache.commons.net.SocketClient.getRemoteAddress(SocketClient.java:651)
        at org.apache.commons.net.ftp.FTPClient._openDataConnection_(FTPClient.java:732)
        at org.apache.commons.net.ftp.FTPClient._retrieveFileStream(FTPClient.java:1853)
        at org.apache.commons.net.ftp.FTPClient.retrieveFileStream(FTPClient.java:1844)
        at Test.main(Test.java:16)

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When I open the file in IE, the file opens just fine, so the link is good. No idea what I am doing wrong! Thanks!

If you create a BufferedReader, consider using that object to read in your data rather than simply ignoring it. As to your NPE, what is happening on line 16 of Test.java?

Thanks. New version:

Code:

---

public static void main(String [] args) throws IOException        {
              FTPClient ftp = new FTPClient();
              InputStream in = ftp.retrieveFileStream("ftp://tgftp.nws.noaa.gov/data/observations/metar/stations/KLAX.TXT");
              InputStreamReader isr = new InputStreamReader(in);
              BufferedReader br = new BufferedReader(isr);
             
         
              String fileContent= br.readLine();
             
              System.out.println(fileContent);

---

Line 16 is pointing to the InputStream line (with the ftp address). I wonder if I am connecting to the ftp correctly...

This worked!!!!!!!

Code:

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public class Test1 {

        public final static String server = "ftp://tgftp.nws.noaa.gov/data/observations/metar/stations";
        public final static String fileName = "UAAA.TXT";
       
       
        public static void main(String[] args) {

                  System.out.println("Connecting to FTP server...");

                    // Connection String
                    URL url;
       
                    try {
                            url = new URL(server + "/" + fileName);

                        URLConnection con = url.openConnection();
                        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));

                        System.out.println("Reading file start.");

                        String inputLine;
                        while ((inputLine = in.readLine()) != null)
                            System.out.println(inputLine);
                        in.close();
                        }
                        catch (FileNotFoundException e) {
                            System.out.println("File not find on server.");
                            System.exit(0);
                        }catch (Exception e) {
                            e.printStackTrace();
                        }
                        System.out.println("Read File Complete.");

                }

}

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Thanks for your support!

I would declare the BufferedReader before the try block setting it initially to null, and would close the BufferedReader in a finally block after checking first that it's not null. Otherwise it looks good.

I did it. Great. Thank you so much!

Great and you're welcome!