small test app for verifying instrumentation (#313)

* small test app for verifying instrumentation

* Update static-instrumenter/test-app/build.gradle.kts

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

* code review

Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

settings.gradle.kts

@@ -47,3 +47,4 @@ include(":samplers")
 include(":static-instrumenter:agent-instrumenter")
 include(":static-instrumenter:gradle-plugin")
 include(":static-instrumenter:maven-plugin")
+include(":static-instrumenter:test-app")

static-instrumenter/test-app/build.gradle.kts

@@ -0,0 +1,30 @@
+plugins {
+  id("otel.java-conventions")
+  id("com.github.johnrengelman.shadow")
+}
+
+description = "OpenTelemetry Java Static Instrumentation Test Application"
+
+dependencies {
+  implementation("org.apache.httpcomponents:httpclient:4.5.13")
+  implementation("org.slf4j:slf4j-api")
+  runtimeOnly("org.slf4j:slf4j-simple")
+}
+
+tasks {
+  withType<JavaCompile>().configureEach {
+    with(options) {
+      release.set(11)
+    }
+  }
+
+  jar {
+    manifest {
+      attributes("Main-Class" to "io.opentelemetry.contrib.staticinstrumenter.test.HttpClientTest")
+    }
+  }
+
+  assemble {
+    dependsOn(shadowJar)
+  }
+}

static-instrumenter/test-app/src/main/java/io/opentelemetry/contrib/staticinstrumenter/test/HttpClientTest.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.contrib.staticinstrumenter.test;
+
+import java.io.IOException;
+import org.apache.http.Header;
+import org.apache.http.HttpEntity;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+
+@SuppressWarnings("SystemOut")
+public final class HttpClientTest {
+
+  private HttpClientTest() {}
+
+  public static void main(String[] args) throws Exception {
+    System.setProperty("otel.traces.exporter", "logging");
+    makeCall();
+  }
+
+  private static void makeCall() throws IOException {
+    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+      HttpGet request = new HttpGet("https://httpbin.org/get");
+      try (CloseableHttpResponse response = httpClient.execute(request)) {
+        HttpEntity entity = response.getEntity();
+        if (entity != null) {
+          Header traceparent = request.getFirstHeader("traceparent");
+          if (traceparent != null) {
+            System.out.println("SUCCESS");
+            System.out.println("Traceparent value: " + traceparent.getValue());
+            return;
+          }
+        }
+      }
+    }
+    System.out.println("FAILURE");
+    return;
+  }
+}