Generic http binding (#225)

Signed-off-by: Matej Vasek <mvasek@redhat.com>

Author: matejvasek

examples/basic-http/pom.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2018-Present The CloudEvents Authors
+  ~ <p>
+  ~ 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
+  ~ <p>
+  ~ http://www.apache.org/licenses/LICENSE-2.0
+  ~ <p>
+  ~ 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.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>cloudevents-examples</artifactId>
+        <groupId>io.cloudevents</groupId>
+        <version>2.0.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>cloudevents-basic-http-example</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.cloudevents</groupId>
+            <artifactId>cloudevents-http-basic</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.cloudevents</groupId>
+            <artifactId>cloudevents-json-jackson</artifactId>
+            <version>${project.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.eclipse.jetty</groupId>
+            <artifactId>jetty-server</artifactId>
+            <version>9.4.28.v20200408</version>
+        </dependency>
+    </dependencies>
+</project>

examples/basic-http/src/main/java/io/cloudevents/examples/http/basic/BasicHttpServer.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2018-Present The CloudEvents Authors
+ * <p>
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.cloudevents.examples.http.basic;
+
+import com.sun.net.httpserver.Headers;
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpServer;
+import io.cloudevents.CloudEvent;
+import io.cloudevents.core.message.MessageReader;
+import io.cloudevents.core.message.MessageWriter;
+import io.cloudevents.http.HttpMessageFactory;
+
+import java.io.*;
+import java.net.InetSocketAddress;
+
+public class BasicHttpServer {
+
+    public static void main(String[] args) throws IOException {
+        HttpServer httpServer = HttpServer.create(new InetSocketAddress("localhost", 8080), 0);
+        httpServer.createContext("/echo", BasicHttpServer::echoHandler);
+        httpServer.start();
+    }
+
+    private static void echoHandler(HttpExchange exchange) throws IOException {
+        if (!"POST".equalsIgnoreCase(exchange.getRequestMethod())) {
+            exchange.sendResponseHeaders(405, 0);
+            return;
+        }
+        try {
+            MessageReader messageReader = createMessageReader(exchange);
+            CloudEvent cloudEvent = messageReader.toEvent();
+
+            System.out.println("Handling event: " + cloudEvent);
+
+            MessageWriter messageWriter = createMessageWriter(exchange);
+            messageWriter.writeBinary(cloudEvent);
+        } catch (Throwable t) {
+            try (ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream()) {
+                try (PrintWriter pw = new PrintWriter(byteArrayOutputStream)) {
+                    t.printStackTrace(pw);
+                }
+                byte[] body = byteArrayOutputStream.toByteArray();
+                exchange.sendResponseHeaders(500, body.length);
+                try (OutputStream outputStream = exchange.getResponseBody()) {
+                    outputStream.write(body);
+                }
+            }
+        }
+    }
+
+    private static MessageReader createMessageReader(HttpExchange httpExchange) throws IOException {
+        Headers headers = httpExchange.getRequestHeaders();
+        byte[] body = IOUtils.toByteArray(httpExchange.getRequestBody());
+        return HttpMessageFactory.createReaderFromMultimap(headers, body);
+    }
+
+    private static MessageWriter createMessageWriter(HttpExchange httpExchange) {
+        return HttpMessageFactory.createWriter(
+            httpExchange.getResponseHeaders()::add,
+            body -> {
+                try {
+                    try (OutputStream os = httpExchange.getResponseBody()){
+                        if (body != null) {
+                            httpExchange.sendResponseHeaders(200, body.length);
+                            os.write(body);
+                        } else {
+                            httpExchange.sendResponseHeaders(204, -1);
+                        }
+                    }
+                } catch (IOException t) {
+                    throw new UncheckedIOException(t);
+                }
+            }
+        );
+    }
+}

examples/basic-http/src/main/java/io/cloudevents/examples/http/basic/HttpURLConnectionClient.java

@@ -0,0 +1,87 @@
+/*
+ * Copyright 2018-Present The CloudEvents Authors
+ * <p>
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.cloudevents.examples.http.basic;
+
+import io.cloudevents.CloudEvent;
+import io.cloudevents.core.message.MessageReader;
+import io.cloudevents.core.message.MessageWriter;
+import io.cloudevents.core.v1.CloudEventBuilder;
+import io.cloudevents.http.HttpMessageFactory;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.UncheckedIOException;
+import java.net.HttpURLConnection;
+import java.net.URI;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Map;
+
+public class HttpURLConnectionClient {
+
+    public static void main(String[] args) throws IOException {
+        CloudEvent ceToSend = new CloudEventBuilder()
+            .withId("my-id")
+            .withSource(URI.create("/myClient"))
+            .withType("dev.knative.cronjob.event")
+            .withDataContentType("application/json")
+            .withData("{ \"msg\" : \"hello\" }".getBytes(StandardCharsets.UTF_8))
+            .build();
+
+
+        URL url = new URL("http://localhost:8080/echo");
+        HttpURLConnection httpUrlConnection = (HttpURLConnection) url.openConnection();
+        httpUrlConnection.setRequestMethod("POST");
+        httpUrlConnection.setDoOutput(true);
+        httpUrlConnection.setDoInput(true);
+
+        MessageWriter messageWriter = createMessageWriter(httpUrlConnection);
+        messageWriter.writeBinary(ceToSend);
+
+        MessageReader messageReader = createMessageReader(httpUrlConnection);
+        CloudEvent receivedCE = messageReader.toEvent();
+
+        System.out.println("CloudEvent: " + receivedCE);
+        System.out.println("Data: " + new String(receivedCE.getData(), StandardCharsets.UTF_8));
+    }
+
+    private static MessageReader createMessageReader(HttpURLConnection httpUrlConnection) throws IOException {
+        Map<String, List<String>> headers = httpUrlConnection.getHeaderFields();
+        byte[] body = IOUtils.toByteArray(httpUrlConnection.getInputStream());
+        return HttpMessageFactory.createReaderFromMultimap(headers, body);
+    }
+
+    private static MessageWriter createMessageWriter(HttpURLConnection httpUrlConnection) {
+        return HttpMessageFactory.createWriter(
+            httpUrlConnection::setRequestProperty,
+            body -> {
+                try {
+                    if (body != null) {
+                        httpUrlConnection.setRequestProperty("content-length", String.valueOf(body.length));
+                        try (OutputStream outputStream = httpUrlConnection.getOutputStream()) {
+                            outputStream.write(body);
+                        }
+                    } else {
+                        httpUrlConnection.setRequestProperty("content-length", "0");
+                    }
+                } catch (IOException t) {
+                    throw new UncheckedIOException(t);
+                }
+            });
+    }
+}

examples/basic-http/src/main/java/io/cloudevents/examples/http/basic/IOUtils.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2018-Present The CloudEvents Authors
+ * <p>
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.cloudevents.examples.http.basic;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+// based on apache's commons-io
+// which is licensed under the Apache License, Version 2.0
+// https://commons.apache.org/proper/commons-io/
+// https://github.com/apache/commons-io/blob/master/src/main/java/org/apache/commons/io/IOUtils.java
+
+public final class IOUtils {
+
+    private IOUtils() {}
+
+    // since Java 9+ you may call InputStream.readAllBytes() instead of this method
+    public static byte[] toByteArray(InputStream body) throws IOException {
+        try (ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream()) {
+            byte[] buff = new byte[(1<<10) * 8];
+            int read;
+            while ((read = body.read(buff)) != -1) {
+                byteArrayOutputStream.write(buff, 0, read);
+            }
+            return byteArrayOutputStream.toByteArray();
+        }
+    }
+}

examples/basic-http/src/main/java/io/cloudevents/examples/http/basic/JettyServer.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2018-Present The CloudEvents Authors
+ * <p>
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.cloudevents.examples.http.basic;
+
+import javax.servlet.ServletOutputStream;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.ServletException;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.net.InetSocketAddress;
+import java.util.Enumeration;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+import io.cloudevents.CloudEvent;
+import io.cloudevents.core.message.MessageReader;
+import io.cloudevents.core.message.MessageWriter;
+import io.cloudevents.http.HttpMessageFactory;
+
+import org.eclipse.jetty.http.HttpStatus;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.server.handler.AbstractHandler;
+
+public class JettyServer {
+
+    private static class Handler extends AbstractHandler {
+
+        @Override
+        public void handle(String uri,
+                           Request request,
+                           HttpServletRequest httpServletRequest,
+                           HttpServletResponse httpServletResponse) throws IOException, ServletException {
+            if (!"/echo".equalsIgnoreCase(uri)) {
+                httpServletResponse.setStatus(HttpStatus.NOT_FOUND_404);
+                return;
+            }
+            if (!"POST".equalsIgnoreCase(request.getMethod())) {
+                httpServletResponse.setStatus(HttpStatus.METHOD_NOT_ALLOWED_405);
+                return;
+            }
+
+            CloudEvent receivedEvent = createMessageReader(httpServletRequest).toEvent();
+            System.out.println("Handling event: " + receivedEvent);
+            createMessageWriter(httpServletResponse).writeBinary(receivedEvent);
+        }
+    }
+
+    private static MessageReader createMessageReader(HttpServletRequest httpServletRequest) throws IOException {
+        Consumer<BiConsumer<String, String>> forEachHeader = processHeader -> {
+            Enumeration<String> headerNames = httpServletRequest.getHeaderNames();
+            while (headerNames.hasMoreElements()) {
+                String name = headerNames.nextElement();
+                processHeader.accept(name, httpServletRequest.getHeader(name));
+
+            }
+        };
+        byte[] body = IOUtils.toByteArray(httpServletRequest.getInputStream());
+        return HttpMessageFactory.createReader(forEachHeader, body);
+    }
+
+    private static MessageWriter createMessageWriter(HttpServletResponse httpServletResponse) throws IOException {
+        return HttpMessageFactory.createWriter(
+            httpServletResponse::addHeader,
+            body -> {
+                try {
+                    try (ServletOutputStream outputStream = httpServletResponse.getOutputStream()) {
+                        if (body != null) {
+                            httpServletResponse.setContentLength(body.length);
+                            httpServletResponse.setStatus(HttpStatus.OK_200);
+                            outputStream.write(body);
+                        } else {
+                            httpServletResponse.setStatus(HttpStatus.NO_CONTENT_204);
+                        }
+                    }
+                } catch (IOException e) {
+                    throw new UncheckedIOException(e);
+                }
+            });
+    }
+
+    public static void main(String[] args) throws Exception {
+        Server server = new Server(new InetSocketAddress("localhost", 8080));
+        server.setHandler(new Handler());
+        server.start();
+        server.join();
+    }
+}

examples/pom.xml

@@ -17,6 +17,7 @@
         <module>kafka</module>
         <module>restful-ws-quarkus</module>
         <module>vertx</module>
+        <module>basic-http</module>
     </modules>