[grid] Printing readable exceptions

When triaging Grid issues, it is common
to see logs with exceptions generated in
the SeleniumSpanExporter. However, they
are json strings printed in a single line,
which makes them really hard to read.

With this change, if the event has information
about an exception, it will be printed in a
human-readable way.

java/src/org/openqa/selenium/remote/tracing/opentelemetry/SeleniumSpanExporter.java

@@ -18,6 +18,12 @@
 package org.openqa.selenium.remote.tracing.opentelemetry;
 
 import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableSet;
+
+import org.openqa.selenium.json.Json;
+import org.openqa.selenium.json.JsonOutput;
+import org.openqa.selenium.remote.tracing.Span;
+
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.trace.StatusCode;
@@ -29,9 +35,6 @@
 import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
-import org.openqa.selenium.json.Json;
-import org.openqa.selenium.json.JsonOutput;
-import org.openqa.selenium.remote.tracing.Span;
 
 import java.util.Collection;
 import java.util.HashMap;
@@ -43,11 +46,24 @@
 
 @AutoService(SdkTracerProviderConfigurer.class)
 public class SeleniumSpanExporter implements SdkTracerProviderConfigurer {
+
   private static final Logger LOG = Logger.getLogger(SeleniumSpanExporter.class.getName());
+  private static final ImmutableSet<String> EXCEPTION_ATTRIBUTES =
+    ImmutableSet.of("exception.message", "exception.stacktrace");
   private final boolean httpLogs = OpenTelemetryTracer.getHttpLogs();
 
+  private static String getJsonString(Map<String, Object> map) {
+    StringBuilder text = new StringBuilder();
+    try (JsonOutput json = new Json().newOutput(text).setPrettyPrint(false)) {
+      json.write(map);
+      text.append('\n');
+    }
+    return text.toString();
+  }
+
   @Override
-  public void configure(SdkTracerProviderBuilder tracerProvider, ConfigProperties configProperties) {
+  public void configure(SdkTracerProviderBuilder tracerProvider,
+                        ConfigProperties configProperties) {
     tracerProvider.addSpanProcessor(SimpleSpanProcessor.create(new SpanExporter() {
       @Override
       public CompletableResultCode export(Collection<SpanData> spans) {
@@ -67,6 +83,14 @@ public CompletableResultCode export(Collection<SpanData> spans) {
 
             Attributes attributes = event.getAttributes();
             map.put("attributes", attributes.asMap());
+
+            EXCEPTION_ATTRIBUTES.forEach(exceptionAttribute -> {
+              attributes.asMap().keySet()
+                .stream()
+                .filter(key -> exceptionAttribute.equalsIgnoreCase(key.getKey()))
+                .findFirst()
+                .ifPresent(key -> LOG.log(logLevel, attributes.asMap().get(key).toString()));
+            });
             String jsonString = getJsonString(map);
             LOG.log(logLevel, jsonString);
           });
@@ -87,15 +111,6 @@ public CompletableResultCode shutdown() {
     }));
   }
 
-  private static String getJsonString(Map<String, Object> map) {
-    StringBuilder text = new StringBuilder();
-    try (JsonOutput json = new Json().newOutput(text).setPrettyPrint(false)) {
-      json.write(map);
-      text.append('\n');
-    }
-    return text.toString();
-  }
-
   private Level getLogLevel(SpanData span) {
     Level level = Level.FINE;