How can I get the users of a JIRA project and add them to a list?

[Alexandre Mathias]

I tried to use ProjectRole to display the users via logging in the console.
Unfortunately, nothing appears.
What am I doing wrong?

public Map createVelocityParams (BrowseContext ctx)
{

Map params = super.createVelocityParams(ctx);
Project project = ctx.getProject();

try {
long projectid = project.getId();
Collection<ProjectRole> projectRoles = projectRoleManager.getProjectRoles();

for (ProjectRole projectRole : projectRoles) {
ProjectRoleActors roleActors = projectRoleManager.getProjectRoleActors(projectRole, project);
Set <ApplicationUser> userSet = roleActors.getUsers();
for(ApplicationUser u : userSet){
log.info("Project: " + project.getName() + "; Role: "+ projectRole.getName() + "; Name: " + u.getName());
}

}