使用servlet将文件上传到Openshift服务器

Question

I'm not sure if this question has been asked before, but I could not find any resources on the internet answering my specific problem.

I am trying to upload a file from an Android app to my Openshift server/gear, where it will be stored. However, the issue I am facing is that whilst the file is being created at the Openshift side (I have checked using FTP), no data is being written to it.

The code snippet from the servlet that writes the data to the file is here:

int BUFFER_LENGTH = 4096;
DataInputStream din = new DataInputStream(req.getInputStream());
String fileName = din.readUTF();
String path = System.getenv("OPENSHIFT_DATA_DIR") + "/uploads/" + fileName + ".txt";
File f = new File(path);
FileOutputStream fos = new FileOutputStream(f);

byte[] buffer = new byte[BUFFER_LENGTH];
int length = 0;
while ((length = din.read(buffer, 0, BUFFER_LENGTH)) != -1) {
    fos.write(buffer, 0, length);
}

fos.close();
din.close();

It all seems to be correct, to me at least, and it worked when I tested it on a local tomcat server. For some reason, however, it doesn't work with Openshift, so there must be something I am missing.

Answer 1

Luckily there is a help center article for just this issue: https://forums.openshift.com/how-to-upload-and-serve-files-using-java-servlets-on-openshift

It details the code for both uploading, and serving files on OpenShift via a Java Servlet, using the openshift data directory