Add a Spring Boot example and integration code.

Change-Id: Ia11dea607c74d9b4cc9a698e9ec92e930bd03f37
diff --git a/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/Application.java b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/Application.java
new file mode 100644
index 0000000..d003b3f
--- /dev/null
+++ b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/Application.java
@@ -0,0 +1,12 @@
+package eu.mulk.quarkus.googlecloud.jsonlogging.example;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+  public static void main(String[] args) {
+    SpringApplication.run(Application.class, args);
+  }
+}
diff --git a/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/ApplicationLoggingSystem.java b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/ApplicationLoggingSystem.java
new file mode 100644
index 0000000..4050b99
--- /dev/null
+++ b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/ApplicationLoggingSystem.java
@@ -0,0 +1,22 @@
+package eu.mulk.quarkus.googlecloud.jsonlogging.example;
+
+import org.springframework.boot.logging.LogFile;
+import org.springframework.boot.logging.LoggingInitializationContext;
+import org.springframework.boot.logging.Slf4JLoggingSystem;
+
+public class ApplicationLoggingSystem extends Slf4JLoggingSystem {
+
+  public ApplicationLoggingSystem(ClassLoader classLoader) {
+    super(classLoader);
+  }
+
+  @Override
+  protected String[] getStandardConfigLocations() {
+    return new String[0];
+  }
+
+  @Override
+  protected void loadDefaults(LoggingInitializationContext initializationContext, LogFile logFile) {
+    /* no configuration necessary */
+  }
+}
diff --git a/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/RandomNumberParameterProvider.java b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/RandomNumberParameterProvider.java
new file mode 100644
index 0000000..7e4158c
--- /dev/null
+++ b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/RandomNumberParameterProvider.java
@@ -0,0 +1,14 @@
+package eu.mulk.quarkus.googlecloud.jsonlogging.example;
+
+import eu.mulk.quarkus.googlecloud.jsonlogging.KeyValueParameter;
+import eu.mulk.quarkus.googlecloud.jsonlogging.StructuredParameter;
+import eu.mulk.quarkus.googlecloud.jsonlogging.StructuredParameterProvider;
+import java.util.concurrent.ThreadLocalRandom;
+
+public class RandomNumberParameterProvider implements StructuredParameterProvider {
+
+  @Override
+  public StructuredParameter getParameter() {
+    return KeyValueParameter.of("randomNumber", ThreadLocalRandom.current().nextInt());
+  }
+}
diff --git a/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/RootResource.java b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/RootResource.java
new file mode 100644
index 0000000..b3197fd
--- /dev/null
+++ b/examples/spring-boot/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/example/RootResource.java
@@ -0,0 +1,33 @@
+package eu.mulk.quarkus.googlecloud.jsonlogging.example;
+
+import eu.mulk.quarkus.googlecloud.jsonlogging.KeyValueParameter;
+import eu.mulk.quarkus.googlecloud.jsonlogging.Label;
+import javax.annotation.PostConstruct;
+import org.jboss.logging.Logger;
+import org.jboss.logging.MDC;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController("/")
+public class RootResource {
+
+  static final Logger log = Logger.getLogger(RootResource.class);
+
+  @PostConstruct
+  public void init() {
+    log.warn("Hey!");
+  }
+
+  @GetMapping(produces = "text/plain")
+  public String hello() {
+    MDC.put("requestMethod", "GET");
+    log.infof(
+        "Hello %s.",
+        "Mulkiatsch",
+        KeyValueParameter.of("a", "b"),
+        Label.of("app", "foo"),
+        KeyValueParameter.of("version", 10));
+    throw new IllegalStateException();
+    // return "ok";
+  }
+}