chore: import upstream snapshot with attribution

03-GettingStarted/06-http-streaming/solution/java/calculator-server/pom.xml

@@ -0,0 +1,50 @@
+<project>
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>com.example</groupId>
+  <artifactId>calculator-server</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+
+  <properties>
+    <java.version>17</java.version>
+    <spring.boot.version>3.3.1</spring.boot.version>
+  </properties>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-dependencies</artifactId>
+        <version>${spring.boot.version}</version>
+        <type>pom</type>
+        <scope>import</scope>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+
+  <dependencies>
+    <!-- Spring Boot WebFlux for SSE -->
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-webflux</artifactId>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.11.0</version>
+        <configuration>
+          <source>${java.version}</source>
+          <target>${java.version}</target>
+          <parameters>true</parameters>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+</project>

03-GettingStarted/06-http-streaming/solution/java/calculator-server/src/main/java/com/example/calculatorserver/CalculatorController.java

@@ -0,0 +1,51 @@
+package com.example.calculatorserver;
+
+import java.time.Duration;
+
+import org.springframework.http.MediaType;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import reactor.core.publisher.Flux;
+import org.springframework.http.codec.ServerSentEvent;
+
+@RestController
+public class CalculatorController {
+
+    @GetMapping(value = "/calculate", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
+    public Flux<ServerSentEvent<String>> calculate(@RequestParam double a,
+                                                   @RequestParam double b,
+                                                   @RequestParam String op) {
+
+        double result;
+        switch (op) {
+            case "add":
+                result = a + b;
+                break;
+            case "sub":
+                result = a - b;
+                break;
+            case "mul":
+                result = a * b;
+                break;
+            case "div":
+                result = b != 0 ? a / b : Double.NaN;
+                break;
+            default:
+                result = Double.NaN;
+        }
+
+        return Flux.<ServerSentEvent<String>>just(
+                    ServerSentEvent.<String>builder()
+                        .event("info")
+                        .data("Calculating: " + a + " " + op + " " + b)
+                        .build(),
+                    ServerSentEvent.<String>builder()
+                        .event("result")
+                        .data(String.valueOf(result))
+                        .build()
+                )
+                .delayElements(Duration.ofSeconds(1));
+    }
+}

03-GettingStarted/06-http-streaming/solution/java/calculator-server/src/main/java/com/example/calculatorserver/CalculatorServerApplication.java

@@ -0,0 +1,12 @@
+package com.example.calculatorserver;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class CalculatorServerApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(CalculatorServerApplication.class, args);
+    }
+}

03-GettingStarted/06-http-streaming/solution/java/calculator-server/src/main/resources/application.yml

@@ -0,0 +1,2 @@
+server:
+  port: 8080