Reading and Uploading files in java

Question

How do I iterate through a directory to read *.csv files and upload them in my system in Java?

Ignore the upload part of post.

Answer 1

You can do something like this to locate all the files in your directory that have a .csv extension.

File[] files = new File(DIR_LOCATION).listFiles(new FileFilter() {
    public boolean accept(File file) {
        return file.getName().endsWith(".csv");
    }
});

Take a look at the File I/O section of the java tutorial

Answer 2

Read Sun's tutorial on this:

http://download-llnw.oracle.com/javase/tutorial/essential/io/dirs.html

Answer 3

Give more specifics. Are you talking about a web application or a standalone application. Simple answer is if it is a web application you can't do that as you can upload only files using file control. If its a standalone app, you can read the dir using list method of file and check if the extension is csv and read it.

Answer 4

You can use File#listFiles() in combination with FilenameFilter to obtain CSV files of a given directory.

File directory = new File("/path/to/your/dir");
File[] csvFiles = directory.listFiles(new FilenameFilter() {
    @Override public boolean accept(File dir, String name) {
        return name.endsWith(".csv");
    }
});

The remnant of the answer depends on how and where you'd like to upload it to. If it's a FTP service, then you'd like to use Apache Commons Net FTPClient. If it's a HTTP service, then you'd like to use Apache HttpComponents Client HttpClient. If you edit your question to clarify the functional requirement, then I may update this answer to include more detail. You should however be aware that you need some sort of a server on the other side to be able to connect and send/upload the file to. E.g. a FTP or HTTP (web) server.

Answer 5

File.list() will get you all the files in a given directory. File.list() returns it as an array of Strings; File.listFiles() returns it as an array of File objects.

You can then loop through the array and pick out all the ones that end in ".csv".

If you want to be a little more sophisticated, create a FilenameFilter that only passes csv files.

Answer 6

Check the File API. Specifically, the File.list* methods; those will list the files in a directory.