接口动态代理IOC注入到spring容器中

public interface StudentService {

    public void add(String studentName);
}

定义一个spring的FactoryBean,FactoryBean在通过spring实例化生成的不是自己本身，而是通过调用的getObject方法返回的对象，该FactoryBean为接口生成一个动态代理的实现。

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import org.springframework.beans.factory.FactoryBean;

public class StudentServiceFactoryBean implements FactoryBean<StudentService>{
    
    private String studentName;

    @Override
    public StudentService getObject() throws Exception {
        //生成数据库访问代理(相当于Mapper的代理)
        StudentService studentService = (StudentService)Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), 
                        new Class<?>[]{StudentService.class}, new MapperInvocationHandler(studentName));
        return studentService;
    }

    @Override
    public Class<?> getObjectType() {
        return StudentService.class;
    }
    
    public String getStudentName() {
        return studentName;
    }

    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }


    public static class MapperInvocationHandler implements InvocationHandler{
        
        private String mapperName;
        
        public MapperInvocationHandler(String mapperName) {
            super();
            this.mapperName = mapperName;
        }



        @Override
        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
            String sql = method.getName();
            if (sql.equals("add")) {
                System.out.println(mapperName+"execute add method"+args[0]);
            }
            return null;
        }
        
    }

}

把该FactoryBean注入到Spring的BeanDefinitionRegistry中:

import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;

public class MyImportBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar {

    @Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        
        try {
            BeanDefinition sbd = new RootBeanDefinition(StudentServiceFactoryBean.class);
            sbd.getPropertyValues().addPropertyValue("studentName", "zhangsan");
            BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(sbd ,"StudentService");
            BeanDefinitionReaderUtils.registerBeanDefinition(definitionHolder, registry);
        }catch(Exception e) {
            
        }

    }

}

测试代码:

@Component
public class MyIncludeBean implements InitializingBean{
    
    @Autowired
    private StudentService studentService;

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("MyIncludeBean:init");
        studentService.add("student111");
    }

}

控制台成功打印:

MyIncludeBean:init
zhangsanexecute add methodstudent111