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by lenkite 90 days ago
Your java knowledge is outdated. Java's JDK has a nice, modern HTTP Client https://docs.oracle.com/en/java/javase/11/docs/api/java.net....
1 comments

Ahh, java. You never change, even if you're modern

    HttpClient client = HttpClient.newBuilder()
        .version(Version.HTTP_1_1)
        .followRedirects(Redirect.NORMAL)
        .connectTimeout(Duration.ofSeconds(20))
        .proxy(ProxySelector.of(
           new InetSocketAddress("proxy.example.com", 80)
        ))
        .authenticator(Authenticator.getDefault())
        .build();

       HttpResponse<String> response = client.send(request, BodyHandlers.ofString());

       System.out.println(response.statusCode());
       System.out.println(response.body());
For the record, you're most likely not even interacting with that API directly if you're using any current framework, because most just provide automagically generated clients and you only define the interface with some annotations
What's the matter with this? It's a clean builder pattern, the response is returned directly from send. I've certainly seen uglier Java
Just my opinion of course, but:

> What's the matter with this?

To me what makes this very "Java" is the arguments being passed, and all the OOP stuff that isn't providing any benefit and isn't really modeling real-world-ish objects (which IMHO is where OOP shines). .version(Version.HTTP_1_1) and .followRedirects(Redirect.NORMAL) I can sort of accept, but it requires knowing what class and value to pass, which is lookups/documentation reference. These are spread out over a bunch of classes. But we start getting so "Java" with the next ones. .connectTimeout(Duration.ofSeconds(20)) (why can't I just pass 20 or 20_000 or something? Do we really need another class and method here?) .proxy(ProxySelector.of(new InetSocketAddress("proxy.example.com", 80))), geez that's complex. .authenticator(Authenticator.getDefault()), why not just pass bearer token or something? Now I have to look up this Authenticator class, initialize it, figure out where it's getting the credentials, how it's inserting them, how I put the credentials in the right place, etc. The important details are hidden/obscured behind needless abstraction layers IMHO.

I think Java is a good language, but most modern Java patterns can get ludicrous with the abstractions. When I was writing lots of Java, I was constantly setting up an ncat listener to hit so I could see what it's actually writing, and then have to hunt down where a certain thing is being done and figuring out the right way to get it to behave correctly. Contrast with a typical Typescript HTTP request and you can mostly tell just from reading the snippet what the actual HTTP request is going to look like.

> but it requires knowing what class and value to pass

Unless you use a text editor without any coding capabilities, your IDE should show you which values you can pass. The alternative is to have more methods, I guess?

> why can't I just pass 20 or 20_000 or something

20 what? Milliseconds? Seconds? Minutes? While I wouldn't write the full Duration.ofSeconds(20) (you can save the "Duration."), I don't understand how one could prefer a version that makes you guess the unit.

> proxy(ProxySelector.of(new InetSocketAddress("proxy.example.com", 80))), geez that's complex

Yes it is, can't add anything here. There's a tradeoff between "do the simple thing" and "make all things possible", and Java chooses the second here.

> .authenticator(Authenticator.getDefault()), why not just pass bearer token or something?

Because this Authenticator is meant for prompting a user interactively. I concur that this is very confusing, but if you want a Bearer token, just set the header.

Fair points.

> Unless you use a text editor without any coding capabilities, your IDE should show you which values you can pass. The alternative is to have more methods, I guess?

Fair enough, as much as I don't like it, in Java world it's safe to assume everyone is using an IDE. And when your language is (essentially) dependent on an IDE, this becomes a non-issue (actually I might argue it's even a nice feature since it's very type safe).

> 20 what? Milliseconds? Seconds? Minutes? While I wouldn't write the full Duration.ofSeconds(20) (you can save the "Duration."), I don't understand how one could prefer a version that makes you guess the unit.

I would assume milliseconds and would probably have it in the method name, like timeoutMs(...) or something. I will say it's very readable, but if I was writing it I'd find it annoying. But optimizing for readability is a reasonable decision, especially since 80% of coding is reading rather than writing (on average).

> why can't I just pass 20 or 20_000 or something? Do we really need another class and method here?

If you've ever dealt with time, you'll be grateful it's a duration and not some random int.

The boilerplate of not having sane defaults. .NET is much simpler:

    using HttpClient client = new();
    HttpResponseMessage response = await client.GetAsync("https://...");
    if (response.StatusCode is HttpStatusCode.OK)
    {
        string s = await response.Content.ReadAsStringAsync();
        // ...
    }
That's just an example. It does have defaults: https://docs.oracle.com/en/java/javase/11/docs/api/java.net.... (search for "If this method is not invoked")
Yeah, so much simpler,

"Common IHttpClientFactory usage issues"

https://learn.microsoft.com/en-us/dotnet/core/extensions/htt...

"Guidelines for using HttpClient"

https://learn.microsoft.com/en-us/dotnet/fundamentals/networ...

And this doesn't account for all gotchas as per .NET version, than only us old timers remember to cross check.

I didn't mention IHttpClientFactory - just HttpClient. I will concede that ASP manages to be confusing quite often. As for the latter, guidelines are not requirements anymore than "RTFM" is; You can use HttpClient without reading the guidelines and be just fine.
For various outcomes of fine, depending on .NET version, given that not everyone is on very latest.
Yeah this is all over Rust codebases too for good reason. The argument is that default params obfuscate behaviour and passing in a struct (in Rust) with defaults kneecaps your ability to validate parameters at compile time.
It does have defaults, the above example manually sets everything to show people reading the docs what that looks like.
> What's the matter with this? It's a clean builder pattern

I feel like you answered yourself. Java makes you do this by not supporting proper keyword arguments.

Your http client setup is over-complicated. You certainly don't need `.proxy` if you are not using a proxy or if you are using the system default proxy, nor do you need `.authenticator` if you are not doing HTTP authentication. Nor do you need `version` since there is already a fallback to HTTP/1.1.

  HttpClient client = HttpClient.newBuilder()
    .followRedirects(Redirect.NORMAL)
    .connectTimeout(Duration.ofSeconds(20))
    .build();
It was literally just copy pasted from the linked source (the official Oracle docs)
And those docs were likely trying to show you how to use multiple features, not the most basic implementation of it
I mean dont get me wrong, I work with Java basically 8 hours per day. I also get _why_ the API is as it is - It essentially boils down to the massive Inversion of Control fetish the Java ecosystem has.

It does enable code that "hides" implementation very well, like the quoted examples authentication API lets you authenticate in any way you can imagine, as in literally any way imaginable.

Its incredibly flexible. Want to only be able to send the request out after you've touched a file, send of a Message through a message broker and then maybe flex by waiting for the response of that async communication and use that as a custom attribute in the payload, additionally to a dynamically negotiated header to be set according to the response of a DNS query? yeah, we can do that! and the caller doesnt have to know any of that... at least as long as it works as intended

Same with the Proxy layer, the client is _entirely_ extensible, it is what Inversion of Control enables.

It just comes with the unfortunate side-effect of forcing the dev to be extremely fluent in enterprisey patterns. I dont mind it anymore, myself. the other day ive even implemented a custom "dependency injection" inspired system for data in a very dynamic application at my dayjob. I did that so the caller wont even need to know what data he needs! it just get automatically resolved through the abstraction. But i strongly suspect if a jr develeoper which hasnt gotten used to the java ecosystem will come across it, he'll be completely out of his depth how the grander system works - even though a dev thats used to it will likely understand the system within a couple of moments.

Like everything in software, everything has advantages and disadvantages. And Java has just historically always tried to "hide complexity", which in practice however paradoxically multiplies complexity _if youre not already used to the pattern used_.

Thanks for the thoughtful response, I appreciate it.

Yeah, I remember the first time I encountered a spring project (well before boot was out) and just about lost my shit with how much magic was happening.

It is productive once you know a whole lot about it though, and I already had to make that investment so might as well reap the rewards.