Spring基础：快速入门spring（3）：构造注入

定义注入依赖的interface

package com.liumiao.demo.spring;

public interface TeachingService {
public String provideTeachingService();
}

定义注入依赖的类

package com.liumiao.demo.spring;

public class SwimmingTeachingService implements TeachingService {
@Override
public String provideTeachingService(){
return "I provide service of teaching swimming.";
}
}

Person interface

package com.liumiao.demo.spring;

public interface Person {
public String sayhello();
public String provideTeachingService();
}

修改构造函数

package com.liumiao.demo.spring;

public class Teacher implements Person{
private TeachingService service;
public Teacher(TeachingService theService){
this.service=theService;
}
public String sayhello(){
return "Hello, I am a teacher";
}
@Override
public String provideTeachingService(){
return service.provideTeachingService();
}
}

配置spring设定文件

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> 
<bean id="thePerson" class="com.liumiao.demo.spring.Teacher">
<constructor-arg ref="theService"></constructor-arg>
</bean>

<bean id="theService" class="com.liumiao.demo.spring.SwimmingTeachingService">
</bean>

</beans>

修改TestDemo

package com.liumiao.demo.spring;

import com.liumiao.demo.spring.Person;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestDemo {
public TestDemo() {
}

public static void main(String[] args) {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:com/liumiao/demo/spring/spring-cfg.xml");
Person person = (Person)context.getBean("thePerson", Person.class);
System.out.println(person.sayhello());
System.out.print(person.provideTeachingService());
context.close();
}
}

执行结果

十一月 26, 2016 6:39:09 下午 org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@25f38edc: startup date [Sat Nov 26 18:39:09 CST 2016]; root of context hierarchy
十一月 26, 2016 6:39:09 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [com/liumiao/demo/spring/spring-cfg.xml]
十一月 26, 2016 6:39:09 下午 org.springframework.context.support.ClassPathXmlApplicationContext doClose
信息: Closing org.springframework.context.support.ClassPathXmlApplicationContext@25f38edc: startup date [Sat Nov 26 18:39:09 CST 2016]; root of context hierarchy
Hello, I am a teacher
I provide service of teaching swimming.