CODEWITHSUNDEEP
javaftpinputstream
CrazySabbath
CrazySabbath

Reputation: 1334

FtpClient retrieveFileStream [hangs]

I have a local FTP server (created with FileZilla server), and there are few XLS files. I need to return file input stream to my Java app so I could parse data etc.

To do so, I tried using FTPClient, but for some reason, while trying to return inputstream from files (bigger than 40KB or) FTPClient.retrieveFileStream() hangs.

I know there are similar questions to this, and I've read them all, at least all that I could find, and nothing helped me. This is really annoying and I'd like some help if possible.

Relevant code parts:

public FTPwrapper(){

    ConfigurableApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
    Properties props = (Properties) context.getBean("ftp_props");

    this.FTPhost = props.getProperty("host");
    this.FTPuser = props.getProperty("user");
    this.FTPpass = props.getProperty("pass");
    this.FTPport = Integer.parseInt(props.getProperty("port"));
    this.filesPath = props.getProperty("filesPath");
    //start ftp connection
    try {
        client.connect(this.FTPhost, this.FTPport);
        client.login(this.FTPuser, this.FTPpass);
        client.setBufferSize(1024 * 1024);
        client.enterLocalPassiveMode();
        client.setFileType(FTP.BINARY_FILE_TYPE);
    } catch (IOException e) {
       e.printStackTrace();
    } 
}

public InputStream returnFileStream(String FileName){

    InputStream inputstream = null;

    try {
        String remoteFile = this.filesPath+FileName;
        inputstream = client.retrieveFileStream(remoteFile);
        client.completePendingCommand();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (client.isConnected()) {
                client.logout();
                client.disconnect();
            }
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }      

    return inputstream;
}

public static void main(String[] args){ 
    FTPwrapper ftp = new FTPwrapper(); 
    InputStream inputstream = ftp.returnFileStream("2012 m muzieju statistika.xls");
}

FPT log:

...login commands...
227 Entering Passive Mode
RETR /vtipsis_data/KT/2012 m muzieju statistika.xls
50 Opening data channel for file download from server of "/vtipsis_data/KT/2012 m muzieju statistika.xls"  //Hangs...

After ftp connection finally time outs, I get java exception: 

java.io.IOException: Your file contains 383 sectors, but the initial DIFAT array at index 4 referenced block # 505. This isn't allowed and  your file is corrupt
    at org.apache.poi.poifs.storage.BlockAllocationTableReader.<init>(BlockAllocationTableReader.java:103)
    at org.apache.poi.poifs.filesystem.POIFSFileSystem.<init>(POIFSFileSystem.java:151)
    at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:322)
    at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(HSSFWorkbook.java:303)

I assume this exception is because only part of my XLS file inputstream is returned. So there it is, my problem. Any ideas how to solve this?

Upvotes: 3

Views: 9956

Answers (1)

CrazySabbath
CrazySabbath

Reputation: 1334

This is not the answer I wanted, but a workaround which will have to suffice... Instead of trying to retrieve stream directly, using retrieveFileStream, I used retrieveFile to download file as a temporary system file, and converted OutputStream, which I got from retrieveFile to InputStream. After that I just delete downloaded temporary file.

Tried using it.sauronsoftware.ftp4j, but It has no method/function similar to retrieveFileStream and can only download file.

EDIT:

I found a way to return file inputstream without using retrieveFileStream or downloading file. Since retrieveFile returns OutputStream, I can just convert OutputStream to InputStream (Why didn't I think of this before?) like:

ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
client.retrieveFile(remoteFile, outputStream);
InputStream inputstream = new ByteArrayInputStream(outputStream.toByteArray());

Upvotes: 7

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