Restore image-thumbnail-samples

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/java/io/spring/example/image/thumbnail/standalone/ThumbnailStandaloneApplication.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2020-2020 the original author or 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.spring.example.image.thumbnail.standalone;
+
+import java.util.Base64;
+import java.util.HashMap;
+import java.util.Map;
+
+import io.spring.example.image.thumbnail.processor.ThumbnailProcessor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.fn.http.request.HttpRequestFunctionConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Import;
+import org.springframework.messaging.support.GenericMessage;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+
+import static org.springframework.cloud.fn.http.request.HttpRequestFunctionConfiguration.HttpRequestFunction;
+
+@SpringBootApplication
+@Controller
+@Import(HttpRequestFunctionConfiguration.class)
+public class ThumbnailStandaloneApplication {
+	private static Logger logger = LoggerFactory.getLogger(ThumbnailStandaloneApplication.class);
+
+	public static void main(String[] args) {
+		SpringApplication.run(ThumbnailStandaloneApplication.class, args);
+	}
+
+	private ThumbnailProcessor thumbnailProcessor = new ThumbnailProcessor();
+
+	@Autowired
+	private HttpRequestFunction httpRequestFunction;
+
+	@Bean
+	RouterFunction<?> routes() {
+		return RouterFunctions.route()
+				.GET("/thumbnail", this::createThumbnail)
+				.build();
+	}
+
+	private Mono<ServerResponse> createThumbnail(ServerRequest serverRequest) {
+		String url = serverRequest.queryParam("url").orElseThrow(() -> new RuntimeException("URL required"));
+
+		return Mono.from(httpRequestFunction.apply(Flux.just(new GenericMessage<>(url)))
+				.flatMap(image -> {
+					Map<String, Object> model = new HashMap<>();
+					byte[] thumbnail = thumbnailProcessor.apply((byte[]) image);
+					logger.info("creating thumbnail for {}", url);
+					model.put("url", url);
+					model.put("thumb", new String(Base64.getEncoder().encode(thumbnail)));
+					Mono<ServerResponse> serverResponse = ServerResponse.ok()
+							.render("thumbnail", model);
+					return serverResponse;
+				}));
+	}
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/resources/application.properties

@@ -0,0 +1,4 @@
+http.request.url-expression=payload
+http.request.expected-response-type=byte[]
+http.request.maximum-buffer-size=2097152
+

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/resources/static/styles/thumbnail.css

@@ -0,0 +1,14 @@
+body {
+    background-color: black;
+}
+h1 {
+    color: palegreen;
+}
+
+img {
+    padding: 10px;
+    border: 2px solid white;
+    display: inline-block;
+    vertical-align: top;
+    max-width: 75%;
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/resources/templates/thumbnail.html

@@ -0,0 +1,15 @@
+<!DOCTYPE HTML>
+<html xmlns:th="http://www.thymeleaf.org">
+<head>
+    <title>Getting Started: Serving Web Content</title>
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
+    <link th:href="@{/styles/thumbnail.css}" rel="stylesheet">
+</head>
+<body>
+<h1 th:text="'Thumbnail for ' + ${url}"/>
+<div class="images">
+    <img id="full" th:src="${url}"/>
+    <img th:src="'data:image/gif;base64,' + ${thumb}" , alt="thumbnail image"/>
+</div>
+</body>
+</html>