How to upload a file, attach and download in corda?

Question

I have tried to upload and send a file with the help of following link https://github.com/corda/corda/tree/release-M14

When I tried to used it in Cordaapp example it is showing many error. Is there any simple example to upload the file and attach? Is there any other simple example to refer the same?

Answer 1

See the Blacklist example here.

You can upload an attachment to a node via HTTP:

<form action="/upload/attachment" method="post" enctype="multipart/form-data">
    <div class="form-group">
        <input type="file" name="jar" class="form-control">
    </div>
    <br>
    <button type="submit" class="btn btn-default">Upload JAR</button>
</form>

Or you can upload an attachment using an RPC client:

val nodeAddress = parse(arg)
val rpcConnection = CordaRPCClient(nodeAddress).start("user1", "test")
val proxy = rpcConnection.proxy

val attachmentHash = uploadAttachment(proxy, JAR_PATH)

Then you add the attachment to a TransactionBuilder as follows:

val txBuilder = TransactionBuilder(notary)
    .addAttachment(attachmentHash)

It is up to you where you get the attachment hash. You may pass it as an argument to the flow, for example.