RFR: 8331195: Improve com.sun.net.httpserver.HttpExchange usability [v4]

[Ethan McCue]

On Wed, 1 May 2024 21:12:05 GMT, robert engels <duke at openjdk.org> wrote:

>> improve the HttpExchange api with documented constants and convenience methods to avoid common bugs
>
> robert engels has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Merge remote-tracking branch 'robaho/HttpExchange-api-change' into HttpExchange-api-change
>    
>    # Conflicts:
>    #	src/jdk.httpserver/share/classes/com/sun/net/httpserver/HttpExchange.java
>  - update api changes based on comments

Maybe it will be a bit easier if we talk about some concrete use cases

## You want to send a response with zero body and you know it up front.

### Without constants


exchange.sendResponseHeaders(200, -1);


### With constants


exchange.sendResponseHeaders(200, HttpExchange.NO_CONTENT);


### With a class to hold the response length


exchange.sendResponseHeaders(200, ResponseLength.known(0));


### With a body abstraction


exchange.sendResponse(200, Body.empty());


## You want to send a response and you can compute the response length, but you don't know it up front and it could be zero

### Without constants


exchange.sendResponseHeaders(200, bytes.length == 0 ? -1 : bytes.length);
try (var body = exchange.getResponseBody) {
    body.write(bytes);
}


### With constants


exchange.sendResponseHeaders(200, bytes.length == 0 ? HttpExchange.NO_CONTENT : bytes.length);
try (var body = exchange.getResponseBody) {
    body.write(bytes);
}


### With a class to hold the response length


exchange.sendResponseHeaders(200, ResponseLength.known(bytes.length));
try (var body = exchange.getResponseBody) {
    body.write(bytes);
}


### With a body abstraction


exchange.sendResponse(200, Body.of(bytes));


## You want to send a response and you cannot compute the response length up front

### Without constants


exchange.sendResponseHeaders(200, 0);
try (var body = exchange.getResponseBody) {
    inputStream.transferTo(body);
}


### With constants


exchange.sendResponseHeaders(200, HttpExchange.CHUNKED_CONTENT);
try (var body = exchange.getResponseBody) {
    inputStream.transferTo(body);
}


### With a class to hold the response length


exchange.sendResponseHeaders(200, ResponseLength.unknown());
try (var body = exchange.getResponseBody) {
    inputStream.transferTo(body);
}


### With a body abstraction


exchange.sendResponse(200, Body.of(inputStream));

-------------

PR Comment: https://git.openjdk.org/jdk/pull/18955#issuecomment-2180978541