Maybe this question could be duplicated. I just can't find any good search words.
How can I provide some development property value to SLSBs?
#LocalBean
#Stateless
class ClouldBean {
public void doSomethingWithUsernameAndPassowrd() {
// ...
}
private String username;
private String password;
}
I just want to know how to inject username and password in a very standard and portable way.
Do I have to use some standard property configuration file?
Do I have to set it be contracted as being provided by container?
Yes, there is standard and portable way and it is called environment entry.
Add following to ejb-jar.xml:
<ejb-jar>
<enterprise-beans>
....
<session>
<ejb-name>ClouldBean</ejb-name>
....
<env-entry>
<env-entry-name>username</env-entry-name>
<env-entry-type>java.lang.String</env-entry-type>
<env-entry-value>my name</env-entry-value>
</env-entry>
...
</session>
</enterprise-beans>
</ejb-jar>
And then you can inject value to the variable in your bean:
#Resource(name="username")
private String username;
For more detailed example you can take a look to this blog post. For all the details best source is EJB 3.1 specification section 16.4.
Related
Can the following class be generated using Clojure's gen-class macro?
public class Test {
public static final String TEST_NAME = "This test's name.";
}
If not, why not?
No, gen-class can't generate static fields because gen-class is for introp. It attempts to give you the power to create the kind of classes demanded by other java libs. It is rare for a java lib to require that you provide a class with a particular static field.
I was wondering how Mybatis get the private variable in Java.
For example:
Let's say we have a Java class called Foo:
public class Foo{
private int foolID;
public Foo(int foolID){
this.foolID = foolID;
}
}
And let's create XML mapper for insert.
<insert id="insert" parameterType="Foo">
insert into foo_table (id)
values (#{foolID});
</insert>
Let's say there are FooDAO java class and FooMapper java interface for this insert.
My question is how come foolID is readable even without Getter (Even if there is a getter method for foolID, I never specify what the getter is...). It seems like magic to me, and I know there is no magic for programming... :)
The only way I can think of is reflection.
Thanks for your help in advance.
That's correct, reflection is used to access private fields, but only if accessing private fields is not restricted.
Seams like reflection is used heavily not just to access private fields but to invoke setters getters etc.
Trying to implement a domain service in a SL app and getting the following error:
Parameter 'spFolderCreate' of domain method 'CreateSharePointFolder' must be an entity type exposed by the DomainService.
[EnableClientAccess()]
public class FileUploadService : DomainService
{
public void CreateSharePointFolder(SharePointFolderCreate spFolderCreate)
{
SharePointFolder spf = new SharePointFolder();
spf.CreateFolder_ClientOM(spFolderCreate.listName, spFolderCreate.fileName);
}
[OperationContract]
void CreateSharePointFolder(SharePointFolderCreate spFolderCreate);
[DataContract]
public class SharePointFolderCreate
{
private string m_listName;
private string m_fileName;
[DataMember]
public string listName
{
get { return m_listName; }
set { m_listName = value; }
}
[DataMember]
public string fileName
{
get { return m_fileName; }
set { m_fileName = value; }
}
}
So am I missing something simple here to make this all work?
It may be that the framework is inferring the intended operation because you have the word "Create" prefixing the function name (CreateSharePointFolder). Details of this behaviour can be found here
Although that is all fine for DomainServices and EntityFramework, following the information in that article, it can be inferred that methods beginning "Delete" will be performing a delete of an entity, so must accept an entity as a parameter. The same is true for "Create" or "Insert" prefixed methods. Only "Get" or "Select" methods can take non-entity parameters, making it possible to pass a numeric id (for example) to a "Get" method.
Try changing your method name temporarily to "BlahSharePointFolder" to see if it is this convention of inferrance that's causing your problem.
Also, as there is no metadata defined for your SharePointFolderCreate DC, you might need to decorate the class (in addition to the [DataContract] attribute) with the [MetadataType] attribute. You will see how to implement this if you used the DomainServiceClass wizard and point to an EF model. There is a checkbox at the bottom for generating metadata. Somewhere in your solution.Web project you should find a domainservice.metadata.cs file. In this file, you will find examples of how to use the [MetadataType] attribute.
For the RIA WCF service to work correctly with your own methods, you need to ensure that all entities existing on the parameter list have at least one member with a [Key] attribute defined in their metadata class, and that the entity is returned somewhere on your DomainService in a "Get" method.
HTH
Lee
Is there any way that I use data annotation as the source of validation in WPF? I want to be able to define a class such as:
class myData
{
[Required]
[MaxLength(50)]
public string Name{get;set;}
}
And then bind it to a field in a view and the wpf validate that user enter some value for this field and also make sure that its length is not greater than 50. I know that I can write a validator for this, but then if I change the maxLength to say 60, then I need to change it in validator and I don't want to have changes in different places.
You need to create a "metadata" definition of the class. You'll need something like this:
[MetadataTypeAttribute(typeof(MyClass.MyClassMetadata))]
public partial class MyClass
{
internal sealed class MyClassMetadata
{
// Metadata classes are not meant to be instantiated.
private MyClassMetadata()
{
}
[Required]
[MaxLength(50)]
public string Name{ get; set; }
}
}
This extends the class with the necessary meta data to support the validation.
Since this question is still left unanswered and I came across it while answering another question that was looking for the same thing, I would share the solution of that question over here too.
The Microsoft TechNet article "Data Validation in MVVM" is a very clean and thorough implementation of using Data Annotations for validation in WPF. I read through the solution myself and would recommend it to others.
I know this must be an age-old, tired question, but I cant seem to find anything thru my trusty friend (aka Google).
I have a .net 3.5 c# winforms app, that presents a user with a login form on application startup. After a successful login, I want to run off to the DB, pull in some user-specific data and hold them (in properties) in a class called AppCurrentUser.cs, that can thereafer be accessed across all classes in the assembly - the purpose here being that I can fill some properties with a once-off data read, instead of making a call to the DB everytime I need to. In a web app, I would usually use Session variables, and I know that the concept of that does not exist in WinForms.
The class structure resembles the following:
public class AppCurrentUser {
public AppCurrentUser() { }
public Guid UserName { get; set; }
public List<string> Roles { get; set; }
public string Firstname { get; set; }
public string Lastname { get; set; }
}
Now, I have some options that I need some expert advice on:
Being a "dumb" class, I should make the properties non-static, instantiate the class and then set the properties...but then I will only be able to access that instance from within the class that it was created in, right?
Logically, I believe that these properties should be static as I will only be using the class once throughout the application (and not creating new instances of it), and it's property values will be "reset" on application close. (If I create an instance of it, I can dispose of it on application close)
How should I structure my class and how do I access its properties across all classes in my assembly? I really would appreciate your honest and valued advice on this!!
Thanks!
Use the singleton pattern here:
public class AppUser
{
private static _current = null;
public static AppUser Current
{
get { return = _current; }
}
public static void Init()
{
if (_current == null)
{
_current = new AppUser();
// Load everything from the DB.
// Name = Dd.GetName();
}
}
public string Name { get; private set; }
}
// App startup.
AppUser.Init();
// Now any form / class / whatever can simply do:
var name = AppUser.Current.Name;
Now the "static" things are thread-unsafe. I'll leave it as an exercise of the reader to figure out how to properly use the lock() syntax to make it thread-safe. You should also handle the case if the Current property is accessed before the call to Init.
It depends on how you setup your architecture. If you're doing all your business logic code inside the actual form (e.g. coupling it to the UI), then you probably want to pass user information in as a parameter when you make a form, then keep a reference to it from within that form. In other words, you'd be implementing a Singleton pattern.
You could also use Dependency Injection, so that every time you request the user object, the dependency injection framework (like StructureMap) will provide you with the right object. -- you could probably use it like a session variable since you'll be working in a stateful environment.
The correct place to store this type of information is in a custom implementation of IIdentity. Any information that you need to identify a user or his access rights can be stored in that object, which is then associated with the current thread and can be queried from the current thread whenever needed.
This principal is illustrated in Rocky Lhotka's CLSA books, or google winforms custom identity.
I'm not convinced this is the right way but you could do something like this (seems to be what you're asking for anyway):
public class Sessions
{
// Variables
private static string _Username;
// properties
public static string Username
{
get
{
return _Username;
}
set
{
_Username = value;
}
}
}
in case the c# is wrong...i'm a vb.net developer...
then you'd just use Sessions.USername etc etc