diff --git a/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/main/java/datadog/trace/instrumentation/servlet3/HttpServletExtractAdapter.java b/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/main/java/datadog/trace/instrumentation/servlet3/HttpServletExtractAdapter.java index b6581323b65..75981facf00 100644 --- a/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/main/java/datadog/trace/instrumentation/servlet3/HttpServletExtractAdapter.java +++ b/dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/main/java/datadog/trace/instrumentation/servlet3/HttpServletExtractAdapter.java @@ -1,7 +1,10 @@ package datadog.trace.instrumentation.servlet3; +import static java.util.Collections.emptyEnumeration; +import static java.util.Collections.enumeration; + import datadog.trace.bootstrap.instrumentation.api.AgentPropagation; -import java.util.Collections; +import java.util.Collection; import java.util.Enumeration; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @@ -41,7 +44,8 @@ public static final class Response extends HttpServletExtractAdapter getHeaderNames(HttpServletResponse response) { - return Collections.enumeration(response.getHeaderNames()); + final Collection headerNames = response.getHeaderNames(); + return headerNames != null ? enumeration(headerNames) : emptyEnumeration(); } @Override