QoSFilter.setMaxRequests throws NullPointerException

[bu3]

Jetty version(s)
9.4.44
Java version/vendor (use: java -version)
openjdk version "11.0.10" 2021-01-19 LTS

OS type/version
macOS 11.6.2

Description
I'm trying to use the QosFilter into an existing Spring application but if I try to tune the filter calling setMaxRequests at configuration time, it throws the following NullPointer exception:

Caused by: java.lang.NullPointerException: null
	at org.eclipse.jetty.servlets.QoSFilter.setMaxRequests(QoSFilter.java:351)

this is the code I'm using to create a Spring Bean with the QosFilter:

@Bean
public QoSFilter sfdcJettyQualityOfServiceFilter(MyQoSProperties properties) {
    QoSFilter qoSFilter = new QoSFilter();
    qoSFilter.setSuspendMs(properties.getSuspendMs());
    qoSFilter.setWaitMs(properties.getWaitMs());
    qoSFilter.setMaxRequests(properties.getMaxRequests());

    return qoSFilter;
}

I think it blows up because QosFilter.init() method has not been called yet at that stage and the private property _passes is null here.

How to reproduce?

• creating a SpringBoot application and trying to load the QosFilter in a @Configuration annotated class

[janbartel]

@bu3 thanks for the report we'll take a look. In the meanwhile, as a workaround, I note that all our unit tests set these properties by calling setInitParam, eg:

        FilterHolder holder = new FilterHolder(QoSFilter.class);
        holder.setInitParameter(QoSFilter.MAX_REQUESTS_INIT_PARAM, x);

[bu3]

Nice! I will give it a try. Thanks a million @janbartel