How do I upload a CSV file and then automatically insert the data into the DB?

Question

I have Java based Spring MVC application that also uses Spring security. I am using hibernate as an ORM tool for this web app.

Following is my requirement --

User will have ability to upload a CSV file using a web browser. The format of the CSV file is known to have following 5 fields:

userId, location, itemId, quantity, tranDate
001, NY, 00A8D5, 2, 12/31/2012
002, MN, 00A7C1, 10, 12/22/2012
.
.

like this there are about 100 rows.

I am using Super CSV in the project:

private void readWithCsvBeanReader(String CSV_FILENAME) throws Exception {

    String CSV_FILENAME = "\\\\Serv01\\Files\\QueryResult.csv";
    //String CSV_FILENAME = "C:\\Files\\QueryResult.csv";
    ICsvBeanReader beanReader = null;
    try {
        beanReader = new CsvBeanReader(new FileReader(CSV_FILENAME),
                CsvPreference.STANDARD_PREFERENCE);

        // the header elements are used to map the values to the bean (names
        // must match)
        final String[] header = beanReader.getHeader(true);
        // get Cell Processor
        final CellProcessor[] processors = getProcessors();

Here I am reading the contents of the CSV file and then using Hibernate, I am inserting it.

This works fine as I am providing the CSV path locally or on the windows share.

String CSV_FILENAME = "\\\\Serv01\\Files\\QueryResult.csv";
or via this:
String CSV_FILENAME = "C:\\Files\\QueryResult.csv"; 

1. How can I achieve this requirement such that the CSV file path location will be provided by a button on the webpage using Spring MVC?

2. Is it also possible to pick up the file automatically from a remote location such that I will upload the file in a FTP location and then the program can connect to the remote ftp location and process the file on a schedule?

PS: I am new to file operations and if someone can point towards some article then it will be great.

Answer 1

like this there are about 100 rows.

Don't bother saving the CSV as a tmp file as Spring's Mulitpart will do that for you and just insert the rows directly ( the request may take longer to process but given your ostensible current knowledge you can worry about optimizing that later )

private void readWithCsvBeanReader(MultipartFile uploadedFile) throws Exception {

    ICsvBeanReader beanReader = null;
    try {
        beanReader = new CsvBeanReader(new InputStreamReader(uploadedFile.getInputStream()),
                CsvPreference.STANDARD_PREFERENCE);

        // the header elements are used to map the values to the bean (names
        // must match)
        final String[] header = beanReader.getHeader(true);
        // get Cell Processor
        final CellProcessor[] processors = getProcessors();

Make your controller something like:

@RequestMapping(value = "/add", method=RequestMethod.POST)
public String upload(@RequestParam("file") MultipartFile file) throws IOException {
// call your csv parsing code.
}

Make sure you make your FORM looks something like:

<h1>Add a File for testing</h1>
<form method="post" action="/add" class="well form-vertical" enctype="multipart/form-data">
    <input type="file" name="file" />
    <button type="submit" class="btn">{{actionLabel}}</button>
</form>

Take notice of the enctype

For input and output you should understand Java's IO Decorator pattern .

I Recommend you keep it as simple as possible so that you can learn the basics. Then worry about adding more robust solutions/libraries.

Answer 2

You need to create a FileUploadController as explained here . Then when you got the file as a stream in your servlet you need to do all the validations and save the file to temporary/permanent location in order to later use it in DB import procedure.

Answer 3

In order to use a remote FTP file location I would look into Spring Integration. The documentation on this is here .