HttpClient.java
/*
* Copyright 2017-2020 original authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.micronaut.http.client;
import io.micronaut.context.LifeCycle;
import io.micronaut.core.annotation.NonNull;
import io.micronaut.core.annotation.Nullable;
import io.micronaut.core.io.buffer.ByteBuffer;
import io.micronaut.core.type.Argument;
import io.micronaut.http.HttpRequest;
import io.micronaut.http.HttpResponse;
import io.micronaut.http.HttpStatus;
import io.micronaut.http.client.exceptions.HttpClientResponseException;
import io.micronaut.http.hateoas.JsonError;
import org.reactivestreams.Publisher;
import reactor.core.publisher.Flux;
import java.io.Closeable;
import java.net.URL;
import java.util.Optional;
/**
* A non-blocking HTTP client interface designed around the Micronaut API and Reactive Streams.
*
* @author Graeme Rocher
* @since 1.0
*/
public interface HttpClient extends Closeable, LifeCycle<HttpClient> {
/**
* The default error type.
*/
Argument<JsonError> DEFAULT_ERROR_TYPE = Argument.of(JsonError.class);
/**
* @return A blocking HTTP client suitable for testing and non-production scenarios.
*/
BlockingHttpClient toBlocking();
/**
* <p>Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.</p>
*
* <p>This method will send a {@code Content-Length} header and except a content length header the response and is
* designed for simple non-streaming exchanges of data</p>
*
* <p>By default the exchange {@code Content-Type} is application/json, unless otherwise specified in the passed
* {@link HttpRequest}</p>
*
* @param request The {@link HttpRequest} to execute
* @param bodyType The body type
* @param errorType The error type
* @param <I> The request body type
* @param <O> The response body type
* @param <E> The error type
* @return A {@link Publisher} that emits the full {@link HttpResponse} object
*/
<I, O, E> Publisher<HttpResponse<O>> exchange(@NonNull HttpRequest<I> request, @NonNull Argument<O> bodyType, @NonNull Argument<E> errorType);
/**
* <p>Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.</p>
*
* <p>This method will send a {@code Content-Length} header and except a content length header the response and is
* designed for simple non-streaming exchanges of data</p>
*
* <p>By default the exchange {@code Content-Type} is application/json, unless otherwise specified in the passed
* {@link HttpRequest}</p>
*
* @param request The {@link HttpRequest} to execute
* @param bodyType The body type
* @param <I> The request body type
* @param <O> The response body type
* @return A {@link Publisher} that emits the full {@link HttpResponse} object
*/
default <I, O> Publisher<HttpResponse<O>> exchange(@NonNull HttpRequest<I> request, @NonNull Argument<O> bodyType) {
return exchange(request, bodyType, DEFAULT_ERROR_TYPE);
}
/**
* Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher}.
*
* @param request The {@link HttpRequest} to execute
* @param <I> The request body type
* @return A {@link Publisher} that emits the full {@link HttpResponse} object
*/
default <I> Publisher<HttpResponse<ByteBuffer>> exchange(@NonNull HttpRequest<I> request) {
return exchange(request, ByteBuffer.class);
}
/**
* Perform an HTTP GET request for the given request object emitting the full HTTP response from returned
* {@link Publisher}.
*
* @param uri The Uri
* @return A {@link Publisher} that emits the full {@link HttpResponse} object
*/
default Publisher<HttpResponse<ByteBuffer>> exchange(@NonNull String uri) {
return exchange(HttpRequest.GET(uri), ByteBuffer.class);
}
/**
* Perform an HTTP GET request for the given request object emitting the full HTTP response from returned
* {@link Publisher}.
*
* @param uri The request URI
* @param bodyType The body type
* @param <O> The response body type
* @return A {@link Publisher} that emits the full {@link HttpResponse} object
*/
default <O> Publisher<HttpResponse<O>> exchange(@NonNull String uri, @NonNull Class<O> bodyType) {
return exchange(HttpRequest.GET(uri), Argument.of(bodyType));
}
/**
* Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.
*
* @param request The {@link HttpRequest} to execute
* @param bodyType The body type
* @param <I> The request body type
* @param <O> The response body type
* @return A {@link Publisher} that emits the full {@link HttpResponse} object
*/
default <I, O> Publisher<HttpResponse<O>> exchange(@NonNull HttpRequest<I> request, @NonNull Class<O> bodyType) {
return exchange(request, Argument.of(bodyType));
}
/**
* Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.
*
* @param request The {@link HttpRequest} to execute
* @param bodyType The body type
* @param errorType The error type
* @param <I> The request body type
* @param <O> The response body type
* @param <E> The error type
* @return A {@link Publisher} that emits a result of the given type
*/
@SuppressWarnings("unchecked")
default <I, O, E> Publisher<O> retrieve(@NonNull HttpRequest<I> request, @NonNull Argument<O> bodyType, @NonNull Argument<E> errorType) {
// note: this default impl isn't used by us anymore, it's overridden by DefaultHttpClient
Flux<HttpResponse<O>> exchange = Flux.from(exchange(request, bodyType, errorType));
if (bodyType.getType() == void.class) {
// exchange() returns a HttpResponse<Void>, we can't map the Void body properly, so just drop it and complete
return (Publisher<O>) exchange.ignoreElements();
}
return exchange.map(response -> {
if (bodyType.getType() == HttpStatus.class) {
return (O) response.getStatus();
} else {
Optional<O> body = response.getBody();
if (!body.isPresent() && response.getBody(byte[].class).isPresent()) {
throw new HttpClientResponseException(
"Failed to decode the body for the given content type [%s]".formatted(response.getContentType().orElse(null)),
response
);
} else {
return body.orElseThrow(() -> new HttpClientResponseException(
"Empty body",
response
));
}
}
});
}
/**
* Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.
*
* @param request The {@link HttpRequest} to execute
* @param bodyType The body type
* @param <I> The request body type
* @param <O> The response body type
* @return A {@link Publisher} that emits a result of the given type
*/
default <I, O> Publisher<O> retrieve(@NonNull HttpRequest<I> request, @NonNull Argument<O> bodyType) {
return retrieve(request, bodyType, DEFAULT_ERROR_TYPE);
}
/**
* Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.
*
* @param request The {@link HttpRequest} to execute
* @param bodyType The body type
* @param <I> The request body type
* @param <O> The response body type
* @return A {@link Publisher} that emits a result of the given type
*/
default <I, O> Publisher<O> retrieve(@NonNull HttpRequest<I> request, @NonNull Class<O> bodyType) {
return retrieve(request, Argument.of(bodyType));
}
/**
* Perform an HTTP request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.
*
* @param request The {@link HttpRequest} to execute
* @param <I> The request body type
* @return A {@link Publisher} that emits String result
*/
default <I> Publisher<String> retrieve(@NonNull HttpRequest<I> request) {
return retrieve(request, String.class);
}
/**
* Perform an HTTP GET request for the given request object emitting the full HTTP response from returned
* {@link Publisher} and converting the response body to the specified type.
*
* @param uri The URI
* @return A {@link Publisher} that emits String result
*/
default Publisher<String> retrieve(@NonNull String uri) {
return retrieve(HttpRequest.GET(uri), String.class);
}
@Override
default HttpClient refresh() {
stop();
return start();
}
/**
* Create a new {@link HttpClient}.
* Note that this method should only be used outside the context of a Micronaut application.
* The returned {@link HttpClient} is not subject to dependency injection.
* The creator is responsible for closing the client to avoid leaking connections.
* Within a Micronaut application use {@link jakarta.inject.Inject} to inject a client instead.
*
* @param url The base URL
* @return The client
*/
static HttpClient create(@Nullable URL url) {
return HttpClientFactoryResolver.getFactory().createClient(url);
}
/**
* Create a new {@link HttpClient} with the specified configuration. Note that this method should only be used
* outside the context of an application. Within Micronaut use {@link jakarta.inject.Inject} to inject a client instead
*
* @param url The base URL
* @param configuration the client configuration
* @return The client
* @since 2.2.0
*/
static HttpClient create(@Nullable URL url, @NonNull HttpClientConfiguration configuration) {
return HttpClientFactoryResolver.getFactory().createClient(url, configuration);
}
}