spring中annotation实例

//person接口

package org.person.dao;

public interface IPerson {
     public String sayhello();
}

 

//teacher类

package org.person.model;

import org.person.dao.IPerson;
import org.springframework.stereotype.Service;

@Service
public class Teacher implements IPerson {

 @Override
 public String sayhello() {
  // TODO Auto-generated method stub
  return "我是一个老师！！";
 }
  
}

//student类

package org.person.model;

import org.person.dao.IPerson;
import org.springframework.stereotype.Service;

@Service
public class Student implements IPerson{

 @Override
 public String sayhello() {
  // TODO Auto-generated method stub
  return "我是一个学生！！";
 }
  
}

//oneclass类

package org.person.model;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service("oneclass")
public class OneClass {
   
 private Student student;
 private Teacher teacher;
   
 @Autowired
 public void setStudent(Student student) {
  this.student = student;
 }
    @Autowired
 public void setTeacher(Teacher teacher) {
  this.teacher = teacher;
 }
 
    public void  say(){
       System.out.println("the student say:" + student.sayhello() + "  the teacher say:"+teacher.sayhello());
    }
}

@Service注释表示定义一个bean，自动根据bean的类名实例化一个首写字母为小写的bean，例如Student实例化为studnet，Teacher实例化为teacher，如果需要自己改名字则:@Service("你自己改的bean名")。

 

beans.xml

<?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:p="http://www.springframework.org/schema/p"
 xmlns:context="http://www.springframework.org/schema/context"
 xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-3.0.xsd
      http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 <context:annotation-config />
 <context:component-scan base-package="*" /><!--  *表示所有类   -->

</beans>

测试类：

package org.person.test;

import org.person.model.OneClass;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
  
 @org.junit.Test
 public void say(){
  ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
  OneClass oneclass = (OneClass)context.getBean("oneclass");
  oneclass.say();
 }
}

结果：

信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@4b035d: startup date [Fri May 18 10:42:47 CST 2012]; root of context hierarchy
2012-5-18 10:42:47 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [beans.xml]
2012-5-18 10:42:48 org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
信息: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@5d391d: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,oneclass,student,teacher,org.springframework.context.annotation.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor#0]; root of factory hierarchy
the student say:我是一个学生！！  the teacher say:我是一个老师！！