Service invocation example using Java and HTTP (#577)

* Service invocation example using HTTP

Signed-off-by: Pravin Pushkar <ppushkar@microsoft.com>

* fixing review feedback

Signed-off-by: Pravin Pushkar <ppushkar@microsoft.com>

service_invocation/java/.gitignore

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+## Maven
+target/
+release.properties
+.mvn
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+# IDE generated files and directories
+*.iml
+.idea/
+*.ipr
+*.iws
+.vs/
+.vscode/
+.code-workspace
+.settings/
+.metadata
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+# macOS
+.DS_Store

service_invocation/java/http/README.md

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+# Service Invocation
+
+In this quickstart, you'll create a checkout service and an order processor service to demonstrate how to use the service invocation API. The checkout service uses Dapr's http proxying capability to invoke a method on the order processing service.
+
+Visit [this](https://docs.dapr.io/developing-applications/building-blocks/service-invocation/) link for more information about Dapr and service invocation.
+
+This quickstart includes one checkout service:
+
+- Java client service `checkout`
+
+And one order processor service:
+
+- Java order-processor service `order-processor`
+
+## Pre-requisites
+
+* [Dapr and Dapr Cli](https://docs.dapr.io/getting-started/install-dapr/).
+* Java JDK 11 (or greater): [Oracle JDK](https://www.oracle.com/technetwork/java/javase/downloads/index.html#JDK11) or [OpenJDK](https://jdk.java.net/11/).
+* [Apache Maven](https://maven.apache.org/install.html) version 3.x.
+
+### Run Java checkout service with Dapr
+
+1. Open a new terminal window and navigate to `checkout` directory:
+
+```bash
+cd checkout
+```
+
+2. Install dependencies:
+
+<!-- STEP
+name: Install maven dependencies
+working_dir: ./checkout
+-->
+
+```bash
+mvn clean install
+```
+
+3. Run the Java checkout app with Dapr:
+
+<!-- STEP
+name: Run Java checkout service
+expected_stdout_lines:
+  - "== APP == Order passed: 1"
+  - "== APP == Order passed: 2"
+expected_stderr_lines:
+output_match_mode: substring
+background: true
+sleep: 10
+-->
+
+```bash
+dapr run --app-id checkout --app-protocol http --dapr-http-port 3500 -- java -jar target/CheckoutService-0.0.1-SNAPSHOT.jar
+```
+
+<!-- END_STEP -->
+
+### Run Java order-processor with Dapr
+
+1. Open a new terminal window and navigate to `order-processor` directory:
+
+```bash
+cd order-processor
+```
+
+2. Install dependencies:
+
+<!-- STEP
+name: Install maven dependencies
+working_dir: ./order-processor
+-->
+
+```bash
+mvn clean install
+```
+
+3. Run the Java order-processor app with Dapr:
+
+<!-- STEP
+name: Run Java checkout service
+expected_stdout_lines:
+  - "== APP == Order received: 1"
+  - "== APP == Order received: 2"
+expected_stderr_lines:
+output_match_mode: substring
+background: true
+sleep: 10
+-->
+
+```bash
+dapr run --app-id order-processor --app-port 6001 --app-protocol http --dapr-http-port 3501 -- java -jar target/OrderProcessingService-0.0.1-SNAPSHOT.jar
+```
+
+<!-- END_STEP -->
+

service_invocation/java/http/checkout/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<groupId>com.service</groupId>
+	<artifactId>CheckoutService</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<description>Demo for Dapr service invocation component</description>
+	<properties>
+		<maven.compiler.source>11</maven.compiler.source>
+		<maven.compiler.target>11</maven.compiler.target>
+		<slf4jVersion>1.6.1</slf4jVersion>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.json</groupId>
+			<artifactId>json</artifactId>
+			<version>20211205</version>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+						<configuration>
+							<mainClass>
+								com.service.CheckoutServiceApplication
+							</mainClass>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

service_invocation/java/http/checkout/src/main/java/com/service/CheckoutServiceApplication.java

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+package com.service;
+
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+import java.util.concurrent.TimeUnit;
+
+public class CheckoutServiceApplication {
+	private static final HttpClient httpClient = HttpClient.newBuilder()
+			.version(HttpClient.Version.HTTP_2)
+			.connectTimeout(Duration.ofSeconds(10))
+			.build();
+
+	private static final String DAPR_HTTP_PORT = System.getenv().getOrDefault("DAPR_HTTP_PORT", "3500");
+
+	public static void main(String[] args) throws InterruptedException, IOException {
+		String dapr_url = "http://localhost:"+DAPR_HTTP_PORT+"/orders";
+		for (int i=1; i<=10; i++) {
+			int orderId = i;
+			JSONObject obj = new JSONObject();
+			obj.put("orderId", orderId);
+
+			HttpRequest request = HttpRequest.newBuilder()
+					.POST(HttpRequest.BodyPublishers.ofString(obj.toString()))
+					.uri(URI.create(dapr_url))
+					.header("Content-Type", "application/json")
+					.header("dapr-app-id", "order-processor")
+					.build();
+
+			HttpResponse<String> response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());
+			System.out.println("Order passed: "+ orderId);
+			TimeUnit.MILLISECONDS.sleep(1000);
+		}
+	}
+}

service_invocation/java/http/order-processor/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.6.3</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.service</groupId>
+	<artifactId>OrderProcessingService</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>OrderProcessingService</name>
+	<description>Demo for Dapr service invocation component</description>
+	<properties>
+		<java.version>11</java.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+			<optional>true</optional>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

service_invocation/java/http/order-processor/src/main/java/com/service/OrderProcessingServiceApplication.java

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+package com.service;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class OrderProcessingServiceApplication {
+	public static void main(String[] args) {
+		SpringApplication.run(OrderProcessingServiceApplication.class, args);
+	}
+}

service_invocation/java/http/order-processor/src/main/java/com/service/controller/OrderProcessingServiceController.java

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+package com.service.controller;
+
+import com.service.model.Order;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class OrderProcessingServiceController {
+    @PostMapping(path = "/orders", consumes = MediaType.ALL_VALUE)
+    public String processOrders(@RequestBody Order body) {
+        System.out.println("Order received: "+ body.getOrderId());
+        return "CID" + body.getOrderId();
+    }
+}

service_invocation/java/http/order-processor/src/main/java/com/service/model/Order.java

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+package com.service.model;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class Order {
+    private int orderId;
+}

service_invocation/java/http/order-processor/src/main/resources/application.properties

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+server.port=${port:6001}