spring boot: scope (一般注入说明(一) @Autowired注解)

DiConfig 文件：

package di;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

//声明当前类是一个配置类
@Configuration
//自动扫描包下的所有@Service,@Component,@Repository和@Controller注册为Bean;
@ComponentScan("di")

public class DiConfig {

}

DFunctionService 文件：
@service相当于 singleton的scope

package di;
import org.springframework.stereotype.Service;

//注入：当前类是spring管理的一个bean
//相当于singleton的scope
@Service
public class DFunctionService {

public String SayHello(String word)
{
return "Hello, " + word + " !";
}

}

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

//注入：当前类是spring管理的一个bean
@Service
public class UseFunctionService {

//将DFunctionService类的实体Bean注入到UseFunctionService中,让UseFunctionService拥有DFunctionService的功能
//等效注解: @Autowire=@Inject=@Resource
@Autowired
DFunctionService functionService;

public String SayHello(String word)
{
return functionService.SayHello(word);
}

}

Main 文件：

package di;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class Main {

public static void main(String args[])
{

AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(DiConfig.class);
UseFunctionService userFunctionService = context.getBean(UseFunctionService.class);
System.out.print(userFunctionService.SayHello("word"));
context.close();

}

}