NetJavaImpl.HttpClientResponse swallowing exceptions thrown by HttpURLConnection

Issue details

HttpClientResponse silently ignores all exceptions thrown by the Connection input stream, including exception thrown if the connection was already closed. After the response content is extracted with getResult (or one of its alternatives), the input stream is closed and subsequent calls to getResult will return an empty byte array, empty stream or empty string, without warning the user.

Possible solutions:

• Cache response result as byte array. Wrap with string or input stream on demand. Make HttpClientResponse thread-safe and reusable.
• Rethrow silently ignored exceptions. I think making HttpResponse a single-use object is somewhat OK, as long as the user is able to track the source of the issue.
• At the very least - add some warning logs for ignored exceptions.

Reproduction

A Kotlin example reproducing the issue - should be trivial to convert to Java:

fun main(args: Array<String>) {
  val net = NetJavaImpl()
  val request = HttpRequest("GET")
  request.url = "http://google.com"
  net.sendHttpRequest(request, object : HttpResponseListener {
    override fun cancelled() = Unit
    override fun failed(t: Throwable?) {
      t?.printStackTrace()
    }
    override fun handleHttpResponse(httpResponse: HttpResponse) {
      println("Content: ${httpResponse.resultAsString}")
      println("Content: ${httpResponse.resultAsString}")
    }
  })
  Thread.sleep(1000L)
}

"Content: " is printed by the second println execution. No exceptions are thrown.

Version of LibGDX

1.9.6, although I'm pretty sure the issue exists in earlier versions.

Please select the affected platforms

• Android
• iOS (robovm)
• iOS (MOE)
• HTML/GWT
• Windows
• Linux
• MacOS

Start at NetJavaImpl.HttpClientResponse and inspect how getResult and its alternatives read and close the Connection input stream. Reproduce the issue with the provided Kotlin example by reading resultAsString twice. Done means a repeated response read no longer silently returns empty content, and any underlying exception is observable.