Avoid NPE on QuartzDecorator (#10181)

Author: amarziali

dd-java-agent/instrumentation/quartz-2.0/src/main/java/datadog/trace/instrumentation/quartz/QuartzDecorator.java

@@ -10,6 +10,8 @@
 import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString;
 import datadog.trace.bootstrap.instrumentation.decorator.BaseDecorator;
 import org.quartz.JobExecutionContext;
+import org.quartz.JobKey;
+import org.quartz.TriggerKey;
 
 public class QuartzDecorator extends BaseDecorator {
   public static final CharSequence SCHEDULED_CALL = UTF8BytesString.create("scheduled.call");
@@ -34,11 +36,21 @@ protected CharSequence component() {
 
   public AgentSpan onExecute(final AgentSpan span, JobExecutionContext context) {
     if (context != null) {
-      span.setTag(DDTags.RESOURCE_NAME, context.getJobInstance().getClass()).toString();
-      span.setTag(QUARTZ_TRIGGER_NAME, context.getTrigger().getKey().getName());
-      span.setTag(QUARTZ_TRIGGER_GROUP, context.getTrigger().getKey().getGroup());
-      span.setTag(QUARTZ_JOB_NAME, context.getTrigger().getJobKey().getName());
-      span.setTag(QUARTZ_JOB_GROUP, context.getTrigger().getJobKey().getGroup());
+      if (context.getJobInstance() != null) {
+        span.setTag(DDTags.RESOURCE_NAME, context.getJobInstance().getClass()).toString();
+      }
+      if (context.getTrigger() != null) {
+        final TriggerKey key = context.getTrigger().getKey();
+        if (key != null) {
+          span.setTag(QUARTZ_TRIGGER_NAME, key.getName());
+          span.setTag(QUARTZ_TRIGGER_GROUP, key.getGroup());
+        }
+        final JobKey jobKey = context.getJobDetail().getKey();
+        if (jobKey != null) {
+          span.setTag(QUARTZ_JOB_NAME, jobKey.getName());
+          span.setTag(QUARTZ_JOB_GROUP, jobKey.getGroup());
+        }
+      }
     }
     return span;
   }