Initialize static field in constructor. It's normal?

Question

public class SharedCacheData : ISharedCacheData
{
    private readonly ISharedPetsService mPetsService;
    private static ISharedEmployeeService mSharedEmployeeService;
 public SharedCacheData(ISharedPetsService petsService, ISharedEmployeeService employeeService)
    {
        mPetsService = petsService;
        mSharedEmployeeService = employeeService;
    }

    public static string GetUserFullName(string key)
    {
        Hashtable value = HttpContext.Current.Application[USERFULLNAME_KEY] as Hashtable;
        if (value == null)
        {
            value = new Hashtable();
            HttpContext.Current.Application[USERFULLNAME_KEY] = value;
        }
        if (value.ContainsKey(key))
            return value[key] as string;

        string name = mSharedEmployeeService.FindOneUser(key);
        value[key] = name;
        return name;
    }

Whether initialize static field mSharedEmployeeService (service) in constructors?

Answer 1

No, that's generally a bad idea. Every time you create a new instance, it will be replacing the static variable. That's almost certainly not what you want to do.

I wonder whether actually there should be two classes here - one for the pets service and one for the employee service. It's hard to tell from the code presented, but what we've got here really doesn't look like a good idea.