Spring继承注入

一.Spring继承(parent)注入

1.抽象继承类使用 abstract="true"
2.子类继承 parent="父类Id"

二.Spring中引用对象方式:

1. local:在当Xml文件中查找对象
<property name="student3">
     <ref local="student3" />
</property>
2. bean:在所有的Xml文件中查找对象
spring 默认使用bean方式
bean有两种方式
方式一：   
<property name="student3">
     <ref bean="student3" />
</property>
方式二： 
<property name="student3" ref="student3"/>   
3. parent：在父对象中查找

三.使用容器加载多个配置文件

(1)数组方式：
      new ClassPathXmlApplicationContext(new String[] {"applicationContext.xml", "".... });
(2)通配符(*)
      new ClassPathXmlApplicationContext("applicationContext*.xml"});
 注意：配置文件命名统一
 例：名字都是以applicationContext开头
       applicationContext.xml(通用配置)
       applicationContext-web.xml
       applicationContext-biz.xml
       applicationContext-dao.xml

举例：

Student1{studentId,studentName,password}

Student2{studentId,studentName}

Student3{address}

Student4{student2,student3}

两个配置文件

applicationContext.xml中

<!-- 公共类必须定义成 abstract="true",让子类继承parent="student" -->
	<bean id="student" abstract="true">
		<property name="studentId" value="1" />
		<property name="studentName" value="老赵" />
	</bean>

	<bean id="student2" class="com.tarena.entity.Student2" parent="student" />

applicationContext-bean.xml中

<bean id="student1" class="com.tarena.entity.Student1" parent="student">
		<property name="password" value="123456" />
	</bean>

	<bean id="student3" class="com.tarena.entity.Student3">
		<property name="address" value="北京海淀" />
	</bean>
	<bean id="student4" class="com.tarena.entity.Student4">
		<property name="student2">
			<!-- 在当前xml文件中找对象 -->
			<ref bean="student2" />
		</property>
		<!--<property name="student3">
			<ref local="student3" />
		</property>
	    -->
	    <property name="student3" ref="student3"/>
	</bean>

测试类：

public class StudetTest {
	private static Log log = LogFactory.getLog(StudetTest.class);
	private ApplicationContext ac;

	@Before
	public void setUp() {
		// ac =new ClassPathXmlApplicationContext("applicationContext.xml");
		/*ac = new ClassPathXmlApplicationContext(new String[] {
				"applicationContext.xml", "applicationContext-bean.xml" });*/
		ac = new ClassPathXmlApplicationContext("applicationContext*.xml");
	}

	@Test
	@Ignore
	public void testStudent1() {
		Student1 student = (Student1) ac.getBean("student1");
		log.info(student.getPassword());
		log.info(student.getStudentId());
		log.info(student.getStudentName());
	}

	@Test
	@Ignore
	public void testStudent2() {
		Student2 student = (Student2) ac.getBean("student2");
		log.info(student.getStudentId());
		log.info(student.getStudentName());
	}

	@Test
	@Ignore
	public void testStudent3() {
		Student3 student = (Student3) ac.getBean("student3");
		log.info(student.getAddress());
	}

	@Test
	//@Ignore
	public void testStudent4() {
		Student4 student4 = (Student4) ac.getBean("student4");
		log.info(student4.getStudent2().getStudentId());
		log.info(student4.getStudent2().getStudentName());
		log.info(student4.getStudent3().getAddress());
	}
}