Usage of EnsureSuccessStatusCode and handling of HttpRequestException it throws

G. Stoynev picture G. Stoynev · Jan 13, 2014 · Viewed 72.5k times · Source

What's the usage pattern of HttpResponseMessage.EnsureSuccessStatusCode()? It disposes of the Content of the message and throws HttpRequestException, but I fail to see how to programmatically handle it any differently than a generic Exception. For example, it doesn't include the HttpStatusCode, which would have been handy.

Is there any way of getting more info out of it? Could anyone show relevant usage pattern of both EnsureSuccessStatusCode() and HttpRequestException?

Answer

Timothy Shields picture Timothy Shields · Jan 16, 2015

The idiomatic usage of EnsureSuccessStatusCode is to concisely verify success of a request, when you don't want to handle failure cases in any specific way. This is especially useful when you want to quickly prototype a client.

When you decide you want to handle failure cases in a specific way, do not do the following.

var response = await client.GetAsync(...);
try
{
    response.EnsureSuccessStatusCode();
    // Handle success
}
catch (HttpRequestException)
{
    // Handle failure
}

This throws an exception just to immediately catch it, which doesn't make any sense. The IsSuccessStatusCode property of HttpResponseMessage is there for this purpose. Do the following instead.

var response = await client.GetAsync(...);
if (response.IsSuccessStatusCode)
{
    // Handle success
}
else
{
    // Handle failure
}