We've recently had a need to accept files submitted by a partner and perform some processing on them, with the partner returning later to retrieve the results. Rather than the "old", standard approach of using something like sftp and regularly kicking off a cron job to look for input files, this seemed like a good case for a Web Service.
And IMO REST style services are simpler to produce (particularly with standard APIs like JAX-RS), consume, and test, and further are a good fit for this particular scenario. (See the excellent book REST
I decided to support the URL "/batch", as an HTTP POST of standard "mul
I should say, I decided to propose this approach and then go see if I could make it happen in a straightforward way. I wasn't sure if submitting files this way was normal enough to be easily supported by JAX-RS and/or WebSphere.
It turns out this is supported by JAX-RS in WebSphere, with a few different mechanisms. Right there in the official IBM Knowledge Center documentation, (almost) everything I needed to know:
So go read that, I'm done :-)
... well, ok, I'll summarize and note a few things, while I'm here.
Generic JAX-RS approach
I generally prefer to stick to the specs, not using any server-specific or impl
With WebSphere, this uploads the file to a temporary location, and gives it a generated file name. (On my Windows development system, the location seems to be my Windows %TEMP% directory.)
However, I'd prefer to prescriptively set the upload directory (so I don't have to later copy it to a more "permanent" location), and I really want the original file's name (among other things, so I can detect when the same file is inadvertently submitted again).
Because of these requirements, I needed to look for another approach.
WebSphere-specific (Apache Wink) approach
It turns out the last example on that
This approach looks more like:
And involves looping through the parts and parsing the HTTP Headers to get the Cont
In addition to the above WebSphere link, also see Apac
I'll note a few problematic behaviors we discovered during the implementation and testing.
Internet Explorer and file input elements
Further, the java
Granted, this service won't normally be called from a browser and HTML page, but during testing, it sometimes is. And even there, using a different browser is acceptable. But still, if it wasn't too much work, I'd prefer to handle this more robustly "just in case".
.NET client error on the GET request
Our partner appears to be using a C# .NET client, and even after he had success submitting a file to our POST URL, he was getting this error upon calling our GET URL from Http
“The server committed a protocol violation. Sect