Spring学习（4）：Spring管理对象之间的关联关系

接着上一节的课程继续学习

MesasageService 类

package hello;import org.springframework.stereotype.Component;
//注解的加入
&＃64;Component
public class MesasageService {public MesasageService() {super();System.out.println("MessageService...");}/*** 执行打印功能* &＃64;return 返回要打印的字符串*/public String getMessage(){return "Hello World";}
}


MessagePrinter类

package hello;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
//注解的加入
&＃64;Component
public class MessagePrinter {//无参构造方法的加入public MessagePrinter() {super();System.out.println("MessagePrinter...");}private MesasageService service;/** 简历和MessageService的关系* *///设置service的值&＃64;Autowired//创建关联关系public void setService(MesasageService service){this.service &＃61;service;}public void printMessage(){System.out.println(this.service.getMessage());}
}


ApplicationSpring类

package hello;import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;//加入扫描
&＃64;ComponentScan
public class ApplicationSpring {public static void main(String[] args){System.out.println("appliaction....");//初始化springApplicationContext context &＃61;new AnnotationConfigApplicationContext(ApplicationSpring.class);//获取messagePrinter对象MessagePrinter printer&＃61;context.getBean(MessagePrinter.class);//获取messafeService对象//MesasageService service&＃61;context.getBean(MesasageService.class);//System.out.println(printer);// System.out.println(service);// printer.setService(service);//打印消息printer.printMessage();}
}


运行结果

appliaction....
10月 27, 2019 6:45:12 下午 org.springframework.context.annotation.AnnotationConfigApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext&＃64;3d012ddd: startup date [Sun Oct 27 18:45:12 CST 2019]; root of context hierarchy
MessageService...
MessagePrinter...
Hello World