feat: Publishing JSON body.

buildSrc/src/main/kotlin/io.github.nstdio.http.ext.test-conventions.gradle.kts

@@ -81,6 +81,7 @@ val brotli4JVersion = "1.8.0"
 val brotliOrgVersion = "0.1.2"
 val gsonVersion = "2.9.1"
 val equalsverifierVersion = "3.10.1"
+val coroutinesVersion = "1.6.4"
 
 val jsonLibs = mapOf(
   "jackson" to "com.fasterxml.jackson.core",
@@ -97,6 +98,8 @@ val spiDeps = listOf(
 dependencies {
   spiDeps.forEach { compileOnly(it) }
 
+  testImplementation(platform("org.jetbrains.kotlinx:kotlinx-coroutines-bom:$coroutinesVersion"))
+
   /** AssertJ & Friends */
   testImplementation("org.assertj:assertj-core:$assertJVersion")
   testImplementation("io.kotest:kotest-assertions-core:$kotestAssertionsVersion")
@@ -116,6 +119,9 @@ dependencies {
   testImplementation("nl.jqno.equalsverifier:equalsverifier:$equalsverifierVersion")
   testImplementation("com.tngtech.archunit:archunit-junit5:1.0.0-rc1")
 
+  /** Kotlin Coroutines */
+  testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-core")
+
   spiDeps.forEach { spiTestImplementation(it) }
   spiTestImplementation("com.aayushatharva.brotli4j:native-${getArch()}:$brotli4JVersion")
 }

src/main/java/io/github/nstdio/http/ext/BodyPublishers.java

@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2022 Edgar Asatryan
+ *
+ * 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
+ *
+ *     http://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.github.nstdio.http.ext;
+
+import io.github.nstdio.http.ext.spi.JsonMappingProvider;
+
+import java.io.ByteArrayOutputStream;
+import java.net.http.HttpRequest.BodyPublisher;
+import java.nio.ByteBuffer;
+import java.util.Optional;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Flow;
+import java.util.concurrent.ForkJoinPool;
+import java.util.function.Supplier;
+
+/**
+ * Implementations of various useful {@link BodyPublisher}s.
+ */
+public final class BodyPublishers {
+  private BodyPublishers() {
+  }
+
+  /**
+   * Returns a request body publisher whose body is JSON representation of {@code body}. The conversion will be done
+   * using {@code JsonMappingProvider} default provider retrieved using {@link JsonMappingProvider#provider()}.
+   *
+   * @param body The body.
+   *
+   * @return a BodyPublisher
+   */
+  public static BodyPublisher ofJson(Object body) {
+    return ofJson(body, JsonMappingProvider.provider());
+  }
+
+  /**
+   * Returns a request body publisher whose body is JSON representation of {@code body}. The conversion will be done
+   * using {@code jsonProvider}.
+   *
+   * @param body         The body.
+   * @param jsonProvider The JSON mapping provider to use when creating JSON presentation of {@code body}.
+   *
+   * @return a BodyPublisher
+   */
+  public static BodyPublisher ofJson(Object body, JsonMappingProvider jsonProvider) {
+    return ofJson(body, jsonProvider, null);
+  }
+
+  /**
+   * Returns a request body publisher whose body is JSON representation of {@code body}. The conversion will be done
+   * using {@code JsonMappingProvider} default provider retrieved using {@link JsonMappingProvider#provider()}.
+   *
+   * @param body     The body.
+   * @param executor The scheduler to use to publish body to subscriber. If {@code null} the *
+   *                 {@link ForkJoinPool#commonPool()} will be used.
+   *
+   * @return a BodyPublisher
+   */
+  public static BodyPublisher ofJson(Object body, Executor executor) {
+    return ofJson(body, JsonMappingProvider.provider(), executor);
+  }
+
+  /**
+   * Returns a request body publisher whose body is JSON representation of {@code body}. The conversion will be done *
+   * using {@code jsonProvider}.
+   *
+   * @param body         The body.
+   * @param jsonProvider The JSON mapping provider to use when creating JSON presentation of {@code body}.
+   * @param executor     The scheduler to use to publish body to subscriber. If {@code null} the
+   *                     {@link ForkJoinPool#commonPool()} will be used.
+   *
+   * @return a BodyPublisher
+   */
+  public static BodyPublisher ofJson(Object body, JsonMappingProvider jsonProvider, Executor executor) {
+    return new JsonPublisher(body, jsonProvider, Optional.ofNullable(executor).orElseGet(ForkJoinPool::commonPool));
+  }
+
+  /**
+   * The {@code BodyPublisher} that converts objects to JSON.
+   */
+  static final class JsonPublisher implements BodyPublisher {
+    private final Object body;
+    private final JsonMappingProvider provider;
+    private final Executor executor;
+
+    JsonPublisher(Object body, JsonMappingProvider provider, Executor executor) {
+      this.body = body;
+      this.provider = provider;
+      this.executor = executor;
+    }
+
+    @Override
+    public void subscribe(Flow.Subscriber<? super ByteBuffer> subscriber) {
+      var subscription = ByteArraySubscription.ofByteBuffer(subscriber, bytesSupplier(), executor);
+
+      subscriber.onSubscribe(subscription);
+    }
+
+    private Supplier<byte[]> bytesSupplier() {
+      return () -> {
+        var os = new ByteArrayOutputStream();
+        try {
+          provider.get().write(body, os);
+        } catch (Throwable e) {
+          Throwables.sneakyThrow(e);
+        }
+
+        return os.toByteArray();
+      };
+    }
+
+    @Override
+    public long contentLength() {
+      return -1;
+    }
+  }
+
+}

src/main/java/io/github/nstdio/http/ext/ByteArraySubscription.java

@@ -18,42 +18,84 @@
 
 import java.nio.ByteBuffer;
 import java.util.List;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Flow.Subscriber;
 import java.util.concurrent.Flow.Subscription;
+import java.util.concurrent.Future;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Function;
+import java.util.function.Supplier;
+
+class ByteArraySubscription<T> implements Subscription {
+  private final Subscriber<T> subscriber;
+  private final Executor executor;
+
+  private final Function<byte[], T> mapper;
+  private final Supplier<byte[]> bytes;
 
-class ByteArraySubscription implements Subscription {
-  private final Subscriber<List<ByteBuffer>> subscriber;
   private final AtomicBoolean completed = new AtomicBoolean(false);
-  private final byte[] bytes;
+  private Future<?> result;
 
-  ByteArraySubscription(Subscriber<List<ByteBuffer>> subscriber, byte[] bytes) {
+  ByteArraySubscription(Subscriber<T> subscriber, Executor executor, Supplier<byte[]> bytes, Function<byte[], T> mapper) {
     this.subscriber = subscriber;
+    this.executor = executor;
     this.bytes = bytes;
+    this.mapper = mapper;
+  }
+
+  static ByteArraySubscription<List<ByteBuffer>> ofByteBufferList(Subscriber<List<ByteBuffer>> subscriber, byte[] bytes) {
+    return new ByteArraySubscription<>(subscriber, DirectExecutor.INSTANCE, () -> bytes, o -> List.of(ByteBuffer.wrap(o).asReadOnlyBuffer()));
+  }
+
+  static ByteArraySubscription<? super ByteBuffer> ofByteBuffer(Subscriber<? super ByteBuffer> subscriber, Supplier<byte[]> bytes, Executor executor) {
+    return new ByteArraySubscription<>(subscriber, executor, bytes, ByteBuffer::wrap);
   }
 
   @Override
   public void request(long n) {
-    if (completed.get()) {
-      return;
-    }
+    if (!completed.getAndSet(true)) {
+      if (n > 0) {
+        submit(() -> {
+          try {
+            T item = mapper.apply(bytes.get());
 
-    if (n <= 0) {
-      subscriber.onError(new IllegalArgumentException("n <= 0"));
-      return;
+            subscriber.onNext(item);
+            subscriber.onComplete();
+          } catch (Throwable th) {
+            subscriber.onError(th);
+          }
+        });
+      } else {
+        var e = new IllegalArgumentException("n <= 0");
+        submit(() -> subscriber.onError(e));
+      }
     }
+  }
 
+  @Override
+  public void cancel() {
     completed.set(true);
 
-    ByteBuffer buffer = ByteBuffer.wrap(bytes).asReadOnlyBuffer();
-    List<ByteBuffer> item = List.of(buffer);
+    if (result != null) {
+      result.cancel(false);
+    }
+  }
 
-    subscriber.onNext(item);
-    subscriber.onComplete();
+  private void submit(Runnable r) {
+    if (executor instanceof ExecutorService) {
+      result = ((ExecutorService) executor).submit(r);
+    } else {
+      executor.execute(r);
+    }
   }
 
-  @Override
-  public void cancel() {
-    completed.set(true);
+  private enum DirectExecutor implements Executor {
+    INSTANCE;
+
+    @Override
+    public void execute(Runnable command) {
+      command.run();
+    }
   }
 }

src/main/java/io/github/nstdio/http/ext/ContentTypeInterceptor.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2022 Edgar Asatryan
+ *
+ * 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
+ *
+ *     http://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.github.nstdio.http.ext;
+
+import io.github.nstdio.http.ext.BodyPublishers.JsonPublisher;
+
+import java.net.http.HttpRequest.BodyPublisher;
+import java.util.Map;
+import java.util.Optional;
+
+import static io.github.nstdio.http.ext.Headers.HEADER_CONTENT_TYPE;
+import static java.util.function.Predicate.not;
+
+class ContentTypeInterceptor implements Interceptor {
+  private final Interceptor headersAdding;
+
+  ContentTypeInterceptor(String contentType) {
+    headersAdding = new HeadersAddingInterceptor(Map.of(HEADER_CONTENT_TYPE, contentType));
+  }
+
+  @Override
+  public <T> Chain<T> intercept(Chain<T> in) {
+    if (!isJsonPublisher(in.request().bodyPublisher())) {
+      return in;
+    }
+
+    return headersAdding.intercept(in);
+  }
+
+  private static boolean isJsonPublisher(Optional<BodyPublisher> bodyPublisher) {
+    return bodyPublisher.filter(not(JsonPublisher.class::isInstance)).isEmpty();
+  }
+}

src/main/java/io/github/nstdio/http/ext/ExtendedHttpClient.java

@@ -47,6 +47,7 @@ public class ExtendedHttpClient extends HttpClient {
   private final CompressionInterceptor compressionInterceptor;
   private final CachingInterceptor cachingInterceptor;
   private final HeadersAddingInterceptor headersAddingInterceptor;
+  private final ContentTypeInterceptor contentTypeInterceptor;
 
   private final HttpClient delegate;
   private final boolean allowInsecure;
@@ -68,6 +69,7 @@ private ExtendedHttpClient(CompressionInterceptor compressionInterceptor,
     this.compressionInterceptor = compressionInterceptor;
     this.cachingInterceptor = cachingInterceptor;
     this.headersAddingInterceptor = headersAddingInterceptor;
+    this.contentTypeInterceptor = new ContentTypeInterceptor("application/json");
     this.delegate = delegate;
     this.allowInsecure = allowInsecure;
   }
@@ -188,6 +190,7 @@ private <T> Chain<T> buildAndExecute(RequestContext ctx) {
     chain = possiblyApply(compressionInterceptor, chain);
     chain = possiblyApply(cachingInterceptor, chain);
     chain = possiblyApply(headersAddingInterceptor, chain);
+    chain = possiblyApply(contentTypeInterceptor, chain);
 
     return chain;
   }

src/main/java/io/github/nstdio/http/ext/Headers.java

@@ -41,6 +41,7 @@ class Headers {
   static final String HEADER_VARY = "Vary";
   static final String HEADER_CONTENT_ENCODING = "Content-Encoding";
   static final String HEADER_CONTENT_LENGTH = "Content-Length";
+  static final String HEADER_CONTENT_TYPE = "Content-Type";
   static final String HEADER_IF_MODIFIED_SINCE = "If-Modified-Since";
   static final String HEADER_IF_NONE_MATCH = "If-None-Match";
   static final String HEADER_CACHE_CONTROL = "Cache-Control";

src/main/java/io/github/nstdio/http/ext/HeadersAddingInterceptor.java

@@ -30,6 +30,10 @@ class HeadersAddingInterceptor implements Interceptor {
     this.headers = headers;
     this.resolvableHeaders = resolvableHeaders;
   }
+
+  HeadersAddingInterceptor(Map<String, String> headers) {
+    this(headers, Map.of());
+  }
 
   @Override
   public <T> Chain<T> intercept(Chain<T> in) {

src/main/java/io/github/nstdio/http/ext/InMemoryCache.java

@@ -89,7 +89,7 @@ public long bodySize() {
 
     @Override
     public void subscribeTo(Flow.Subscriber<List<ByteBuffer>> sub) {
-      Flow.Subscription subscription = new ByteArraySubscription(sub, body);
+      Flow.Subscription subscription = ByteArraySubscription.ofByteBufferList(sub, body);
       sub.onSubscribe(subscription);
     }
 

src/main/java/io/github/nstdio/http/ext/spi/GsonJsonMapping.java

@@ -23,6 +23,8 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
 import java.lang.reflect.Type;
 import java.util.Objects;
 
@@ -67,4 +69,11 @@ public <T> T read(byte[] bytes, Class<T> targetType) throws IOException {
   public <T> T read(byte[] bytes, Type targetType) throws IOException {
     return read(new ByteArrayInputStream(bytes), targetType);
   }
+
+  @Override
+  public void write(Object o, OutputStream os) throws IOException {
+    try (var writer = new OutputStreamWriter(os, UTF_8)) {
+      gson.toJson(o, writer);
+    }
+  }
 }