spring学习笔记（二）

   spring提供了两种IOC轻量级容器，BeanFactory和ApplicationContext，然而这两种容器有明显的区别，前者是延迟加载初始化，只有当客户端在要访问其中受管的对象的时候才去初始化。ApplicationContext是在容器启动之后全部绑定实例化对象，然而这些bean对象的实例化是容器通过Java类提供的默认构造函数来实例化，若Java类没有提供默认构造器，则会报org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'personservice' 异常。容器提供了三种实例化对象的方式，包括静态工厂，实例化工厂，构造函数。
         静态工厂实例化：
          1 定义接口
             public interface PersonService{
                   public void save();
              }
          2  接口实现类
              public class PersonServieImpl implements PersonService{
                //PersonServieImpl(int x){ }
                 @Override
                 public void save() {
                    System.out.println("保存方法");
                 }
                }
           3  工厂类
              public class PersonFactory{
                 public staic PersonService create(){
                    return new PersonServieImpl();
                  }
              }
            4 配置文件
               <?xml version="1.0" encoding="UTF-8"?>
              <beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                     xmlns:context="http://www.springframework.org/schema/context"
                     xmlns:aop="http://www.springframework.org/schema/aop"
                     xsi:schemaLocation="http://www.springframework.org/schema/beans
                     http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">

    <bean id="personservice" class="com.dt.study.serviceimpl.PersonServieImpl"/>
    <bean id="personFactory" class="com.dt.study.util.PersonFactory" factory-method="createBean"/>
</beans>
                5 测试类
                  public class SpringTest {
                         @Test
                         public void savetest(){
                            ApplicationContext context = new ClassPathXmlApplicationContext ("applicationContext.xml");
                           PersonServieImpl personimpl = (PersonServieImpl)context.getBean("personFactory");
                           personimpl.save();
}
}