Add null checks to constructors

[jzheaux]

Related to #6542

RequestKey, JaasGrantedAuthority, and SwitchUserGrantedAuthority each anticipate certain final members will be non-null without requiring such in the constructor.

For example, RequestKey does the following in equals:

if (!url.equals(key.url)) {
    return false;
}

Where url is a member variable. But, the constructor does nothing to ensure this behavior will actually work:

public RequestKey(String url, String method) {
    this.url = url;
    this.method = method;
}

For RequestKey, we should change the constructor to something like:

public RequestKey(String url, String method) {
    Assert.notNull(url, "url cannot be null");
    this.url = url;
    this.method = method;
}

And we'd do similar things for the other two classes.

[clementkng]

Hi @jzheaux, is this issue open for contribution? If so, I would like to try working on this since I'm interested in learning more about this project.

[jzheaux]

Yes, @clementkng, it certainly is. Thanks for your interest! The ticket is yours.

[dfcoffin]

@jzheaux is there a list of which class constructors and values should be verified as containing non-null values?

[jzheaux]

Thanks for the question, @dfcoffin:

RequestKey -> url
JaasGrantedAuthority -> role, principal
SwitchUserGrantedAuthority -> role, source

[clementkng]

@jzheaux the integration test seems to be failing for me locally even though I am running ./gradlew clean build integrationTest on master with no changes. I'm not sure if this OK behavior, and whether we're supposed to run the above command or ./gradlew build suffices for testing.

[jzheaux]

What is the error you're seeing? Note that integrationTest on the full suite fails for JDK 11 on some of the samples.

[clementkng]

I'm currently running the project on the Windows Subsystem for Linux using JDK 10. Just wanted to make sure it's unexpected behavior before diving in. I'm getting a selenium.NoSuchElementException and a junit.ComparisonFailure.

[clementkng]

@jzheaux I've created a PR for the issue here

[jzheaux]

Fixed via e66369f