chore: add quickstart example with java (#3281)

* chore: add quickstart example with java

* update: readme with details about Java implementation

examples/quick-start-java/.gitignore

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+.DS_Store
+.gradle

examples/quick-start-java/README.md

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+# Quick Start - Java app with OpenTelemetry and Tracetest
+
+> [Read the detailed recipe for setting up OpenTelemetry Collector with Tractest in our documentation.](https://docs.tracetest.io/examples-tutorials/recipes/running-tracetest-without-a-trace-data-store)
+This is a simple quick start on how to configure a Java app (with [Spring](https://spring.io/)) to use OpenTelemetry instrumentation with traces, and Tracetest for enhancing your e2e and integration tests with trace-based testing.
+
+The Java API was created with OpenTelemetry instrumentation using the [OpenTelemetry with Java guidelines](https://opentelemetry.io/docs/instrumentation/java/getting-started/).
+
+To run it just execute `docker compose up` on this folder.
+
+Feel free to check out the [docs](https://docs.tracetest.io/), and join our [Discord Community](https://discord.gg/8MtcMrQNbX) for more info!

examples/quick-start-java/docker-compose.yaml

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+version: '3'
+services:
+  app:
+    image: quick-start-java
+    build: ./quick_start_api/.
+    platform: linux/amd64
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
+    ports:
+      - "8080:8080"
+    environment:
+      OTEL_SERVICE_NAME: quick_start_java
+      OTEL_TRACES_EXPORTER: otlp
+      OTEL_METRICS_EXPORTER: none
+      OTEL_LOGS_EXPORTER: none
+      OTEL_EXPORTER_OTLP_TRACES_ENDPOINT: http://otel-collector:4317
+
+  tracetest:
+    image: kubeshop/tracetest:latest
+    platform: linux/amd64
+    volumes:
+      - type: bind
+        source: ./tracetest/tracetest-config.yaml
+        target: /app/tracetest.yaml
+      - type: bind
+        source: ./tracetest/tracetest-provision.yaml
+        target: /app/provisioning.yaml
+    ports:
+      - 11633:11633
+    command: --provisioning-file /app/provisioning.yaml
+    depends_on:
+      postgres:
+        condition: service_healthy
+      otel-collector:
+        condition: service_started
+    healthcheck:
+      test: ["CMD", "wget", "--spider", "localhost:11633"]
+      interval: 1s
+      timeout: 3s
+      retries: 60
+    environment:
+      TRACETEST_DEV: ${TRACETEST_DEV}
+
+  postgres:
+    image: postgres:14
+    environment:
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_USER: postgres
+    healthcheck:
+      test: pg_isready -U "$$POSTGRES_USER" -d "$$POSTGRES_DB"
+      interval: 1s
+      timeout: 5s
+      retries: 60
+
+  otel-collector:
+    image: otel/opentelemetry-collector-contrib:0.59.0
+    command:
+      - "--config"
+      - "/otel-local-config.yaml"
+    volumes:
+      - ./tracetest/collector.config.yaml:/otel-local-config.yaml

examples/quick-start-java/quick_start_api/.gitattributes

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+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew        text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat           text eol=crlf
+

examples/quick-start-java/quick_start_api/.gitignore

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+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build

examples/quick-start-java/quick_start_api/Dockerfile

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+#based on https://github.com/open-telemetry/opentelemetry-demo/blob/main/src/adservice/Dockerfile
+
+FROM eclipse-temurin:17-jdk AS builder
+
+WORKDIR /usr/src/app/
+
+COPY ./gradlew* ./settings.gradle* .
+COPY ./gradle ./gradle
+COPY ./app ./app
+
+RUN ./gradlew
+RUN ./gradlew assemble
+
+FROM eclipse-temurin:17-jre
+
+WORKDIR /usr/src/app/
+
+COPY --from=builder /usr/src/app/ ./
+
+ENTRYPOINT [ "java", "-jar", "./app/build/libs/app.jar" ]

examples/quick-start-java/quick_start_api/app/build.gradle.kts

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+plugins {
+  id("java")
+  id("org.springframework.boot") version "3.0.6"
+  id("io.spring.dependency-management") version "1.1.0"
+}
+
+repositories {
+  mavenCentral()
+}
+
+dependencies {
+  implementation("org.springframework.boot:spring-boot-starter-web")
+
+  // OpenTelemetry core
+  implementation(platform("io.opentelemetry:opentelemetry-bom:1.31.0"))
+  implementation("io.opentelemetry:opentelemetry-api")
+  implementation("io.opentelemetry:opentelemetry-sdk")
+  implementation("io.opentelemetry:opentelemetry-exporter-otlp")
+  implementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure")
+  implementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi")
+
+  // OpenTelemetry instrumentation
+  implementation(platform("io.opentelemetry.instrumentation:opentelemetry-instrumentation-bom-alpha:1.31.0-alpha"))
+  implementation("io.opentelemetry.instrumentation:opentelemetry-runtime-telemetry-java8")
+  implementation("io.opentelemetry.instrumentation:opentelemetry-log4j-appender-2.17")
+  implementation("io.opentelemetry.instrumentation:opentelemetry-spring-webmvc-6.0")
+
+  // implementation(platform("io.opentelemetry:opentelemetry-bom:1.31.0"))
+  // implementation("io.opentelemetry:opentelemetry-api:1.31.0")
+  // implementation("io.opentelemetry:opentelemetry-sdk:1.31.0")
+  // implementation("io.opentelemetry:opentelemetry-sdk-metrics:1.31.0")
+  // implementation("io.opentelemetry.semconv:opentelemetry-semconv:1.21.0-alpha")
+  // implementation("io.opentelemetry:opentelemetry-exporter-otlp:1.31.0")
+  // implementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure:1.31.0")
+  // implementation("io.opentelemetry:opentelemetry-sdk-extension-autoconfigure-spi:1.31.0")
+
+  // implementation("io.opentelemetry.instrumentation:opentelemetry-spring-webmvc-6.0")
+}
+
+java {
+  toolchain {
+    languageVersion.set(JavaLanguageVersion.of(17))
+  }
+}
+
+sourceSets {
+  main {
+    java.setSrcDirs(setOf("."))
+  }
+}
+
+ext {
+    set("opentelemetry.version", "1.31.0")
+}

examples/quick-start-java/quick_start_api/app/src/main/java/quick_start_api/HelloController.java

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+package quick_start_api;
+
+import java.util.List;
+import java.util.Optional;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.context.Scope;
+
+@RestController
+public class HelloController {
+  private final Tracer tracer;
+
+  @GetMapping("/hello")
+  public String index() {
+    Span span = tracer.spanBuilder("hello").startSpan();
+
+    try (Scope scope = span.makeCurrent()) {
+      return "hello";
+    } catch(Throwable t) {
+      span.recordException(t);
+      throw t;
+    } finally {
+      span.end();
+    }
+  }
+
+  @Autowired
+  HelloController(OpenTelemetry openTelemetry) {
+    tracer = openTelemetry.getTracer(HelloController.class.getName(), "0.1.0");
+  }
+}

examples/quick-start-java/quick_start_api/app/src/main/java/quick_start_api/QuickStartApplication.java

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+package quick_start_api;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.Banner;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+import jakarta.servlet.Filter;
+
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
+import io.opentelemetry.instrumentation.spring.webmvc.v6_0.SpringWebMvcTelemetry;
+
+@SpringBootApplication
+public class QuickStartApplication {
+  private static volatile OpenTelemetry openTelemetry = OpenTelemetry.noop();
+
+  public static void main(String[] args) {
+    OpenTelemetrySdk openTelemetrySdk = AutoConfiguredOpenTelemetrySdk.builder().build().getOpenTelemetrySdk();
+    QuickStartApplication.openTelemetry = openTelemetrySdk;
+
+    SpringApplication app = new SpringApplication(QuickStartApplication.class);
+    app.setBannerMode(Banner.Mode.OFF);
+    app.run(args);
+  }
+
+  @Bean
+  public OpenTelemetry openTelemetry() {
+    return openTelemetry;
+  }
+
+  @Bean
+  public Filter webMvcTracingFilter(OpenTelemetry openTelemetry) {
+      return SpringWebMvcTelemetry.create(openTelemetry).createServletFilter();
+  }
+}

examples/quick-start-java/quick_start_api/gradle/wrapper/gradle-wrapper.properties

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+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists