Detailed explanation of dependency injection function in SpringBoot

This article mainly introduces the detailed implementation of dependency injection function in SpringBoot. The implementation of SpringBoot is basically implemented through annotations. Those who are interested can find out.

Today I will introduce to you how to implement dependency injection in SpringBoot.

In the past use of spring, dependency injection was generally implemented by adding bean methods in the Spring configuration file. Compared with this method, SpringBoot's implementation is very convenient. SpringBoot's implementation is basically implemented through annotations.

Let’s take a look at a specific case. Here I have written three test classes to test whether dependency injection can be implemented correctly.

TestBiz interface:

package example.biz; 
public interface TestBiz { 
  public String getTest(String str); 
}

TestBizImp interface implementation class:

package example.biz.imp; 
import example.biz.TestBiz; 
import org.springframework.stereotype.Component; 
/** 
  @Service用于标注业务层组件 
  @Controller用于标注控制层组件（如struts中的action） 
  @Repository用于标注数据访问组件，即DAO组件 
  @Component泛指组件，当组件不好归类的时候，我们可以使用这个注解进行标注。 
 */ 
@Component 
public class TestBizImp implements TestBiz { 
  @Override 
  public String getTest(String str) { 
    return "Return value is:"+str; 
  } 
}

Here you can see the four annotations given above, which All four annotations can actually implement the injection function, but their uses are different. It is best to add these annotations according to the specific business.

TestController class:

@Controller 
public class TestController { 
  @Autowired 
  private TestBiz testBiz; 
  @RequestMapping("/getTest") 
  @ResponseBody 
  public String getTest(String str){ 
    return testBiz.getTest(str); 
  } 
}

Here you need to add the @Autowired annotation on the interface. The function of this annotation is to implement the instantiation operation of TestBiz, which is equivalent to the bean operation in Spring.
After completing this, you can start the project and test whether dependency injection has been implemented. The running results are as follows:

In this way, SpringBoot has implemented the dependency injection function. Isn’t it much simpler than Spring’s implementation process?

The above is the detailed content of Detailed explanation of dependency injection function in SpringBoot. For more information, please follow other related articles on the PHP Chinese website!