Spring.NET教程（五）——容器中對象的作用域(基礎篇)

        容器中對象的部署分爲兩種方式：singleton和非singleton(java裏叫prototype)。這裏的singleton指的是“單例模式”，就是說當一個對象被定義爲singleton時，容器中就只會有一個共享的實例，任何時候通過id或別名請求該對象都會返回這個共享實例的引用（也就是說這個對象只會被創建一次）。當使用非singleton，或者說原型模式佈署時，每次請求對象都會創建新的實例。在某些場合，如果需要爲每個用戶返回單獨的用戶對象或其它對象，非singlton佈署模式就比較理想。Spring.NET默認爲singleton模式。每次調用GetObject方法時得到的都是同樣的實例；當singleton="false"時，每次調用GetObject方法時得到的則是不同的實例。

<?xml version="1.0" encoding="utf-8" ?>
<objects xmlns="http://www.springframework.net">
  <!--單例模式-->
  <object id="personDao" type="SpringNetScopes.PersonDao,　SpringNetScopes"/>
  <!--非單例模式-->
  <object id="person" type="SpringNetScopes.Person,　SpringNetScopes" singleton="false" />
  <!--調用時加載-->
  <object id="personServer" type="SpringNetScopes.PersonServer,　SpringNetScopes" lazy-init="true"/>
</objects>

namespace SpringNetScopes
{
    public class PersonDao : IPersonDao
    {
        public PersonDao()
        {
            Console.WriteLine("PersonDao被實例");
        }
        public override string ToString()
        {
            return "我是PersonDao";
        }
        ~PersonDao()
        {
            Console.WriteLine("PersonDao被銷燬");
        }
        public void Save()
        {
            Console.WriteLine("保存　Person");
        }
    }
    public class Person
    {
        public Person()
        {
            Console.WriteLine("Person被實例");
        }
        public override string ToString()
        {
            return "我是Person";
        }
        ~Person()
        {
            Console.WriteLine("Person被銷燬");
        }
    }
    public class PersonServer
    {
        public PersonServer()
        {
            Console.WriteLine("PersonServer被實例");
        }
        public override string ToString()
        {
            return "我是PersonServer";
        }
        ~PersonServer()
        {
            Console.WriteLine("PersonServer被銷燬");
        }
    }

}


        [TestMethod]
        public void CreateWithSingleton()
        {
            string[] xmlFiles = new string[]
            {
                "assembly://SpringNetScopes/SpringNetScopes/Objects.xml"
            };
            IApplicationContext context = new XmlApplicationContext(xmlFiles);
            IObjectFactory factory = (IObjectFactory)context;
            object obj1 = factory.GetObject("personDao");
            object obj2 = factory.GetObject("personDao");
            Assert.AreEqual(obj1, obj2);
        }
        [TestMethod]
        public void CreateWithOutSingleton()
        {
            string[] xmlFiles = new string[]
            {
                "assembly://SpringNetScopes/SpringNetScopes/Objects.xml"
            };
            IApplicationContext context = new XmlApplicationContext(xmlFiles);
            IObjectFactory factory = (IObjectFactory)context;
            object obj1 = factory.GetObject("person");
            object obj2 = factory.GetObject("person");
            Assert.AreNotEqual(obj1, obj2);
        }
        [TestMethod]
        public void CreateWithLazy()
        {
            string[] xmlFiles = new string[]
            {
                "assembly://SpringNetScopes/SpringNetScopes/Objects.xml"
            };
            IApplicationContext context = new XmlApplicationContext(xmlFiles);
            IObjectFactory factory = (IObjectFactory)context;
            object dao = factory.GetObject("personDao");
            Console.WriteLine(dao.ToString());
            object server = factory.GetObject("personServer");
            Console.WriteLine(server.ToString());
        }