CASE

image.png

基类

import com.alibaba.dubbo.config.annotation.Reference;
import com.abci.IAbtDispacherService;

public abstract class AbstractService {
    @Reference(version = "1.0", registry = "provider", timeout = 50, retries = -1, lazy = true)
    public IAbtDispacherService iAbtDispacherService;//这里为空

    public void test() {
        System.out.println(iAbtDispacherService);
    }

}

子类

@RunWith(SpringRunner.class)
@ContextConfiguration(classes = {MSApplication.class},
        initializers = {ConfigFileApplicationContextInitializer.class})

public class HomePageTest extends AbstractService{

    @Reference(version = "1.0", registry = "provider", timeout = 50, retries = -1, lazy = true)
    public IAbtDispacherService iAbtDispacherService22;


    @Test
    public void missFreshHomepage() {
        this.test();
        
    }
}

原因(Field field : objClz.getDeclaredFields)

package com.alibaba.dubbo.spring.boot;

import java.lang.reflect.Field;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.springframework.aop.support.AopUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanCreationException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.env.Environment;

import com.alibaba.dubbo.config.annotation.Reference;
import com.alibaba.dubbo.config.annotation.Service;
import com.alibaba.dubbo.config.spring.ReferenceBean;
import com.alibaba.dubbo.spring.boot.annotation.EnableDubboConfiguration;
import com.alibaba.dubbo.spring.boot.bean.ClassIdBean;

/**
 * DubboConsumerAutoConfiguration
 *
 * @author xionghui
 * @version 2.0.0
 * @since 1.0.0
 */
@Configuration
@ConditionalOnClass(Service.class)
@ConditionalOnBean(annotation = EnableDubboConfiguration.class)
@AutoConfigureAfter(DubboAutoConfiguration.class)
@EnableConfigurationProperties(DubboProperties.class)
public class DubboConsumerAutoConfiguration extends DubboCommonAutoConfiguration {
  private static final Map<ClassIdBean, Object> DUBBO_REFERENCES_MAP =
      new ConcurrentHashMap<ClassIdBean, Object>();

  @Autowired
  private ApplicationContext applicationContext;
  @Autowired
  private DubboProperties properties;

  public static Object getDubboReference(ClassIdBean classIdBean) {
    return DUBBO_REFERENCES_MAP.get(classIdBean);
  }

  @Bean
  public BeanPostProcessor beanPostProcessor() {
    return new BeanPostProcessor() {

      @Override
      public Object postProcessBeforeInitialization(Object bean, String beanName)
          throws BeansException {
        Class<?> objClz;
        if (AopUtils.isAopProxy(bean)) {
          objClz = AopUtils.getTargetClass(bean);
        } else {
          objClz = bean.getClass();
        }

        try {
          for (Field field : objClz.getDeclaredFields()) {//"这里有bug"
            Reference reference = field.getAnnotation(Reference.class);
            if (reference != null) {
              DubboConsumerAutoConfiguration.this
                  .initIdConfigMap(DubboConsumerAutoConfiguration.this.properties);
              ReferenceBean<?> referenceBean =
                  DubboConsumerAutoConfiguration.this.getConsumerBean(beanName, field, reference);
              Class<?> interfaceClass = referenceBean.getInterfaceClass();
              String group = referenceBean.getGroup();
              String version = referenceBean.getVersion();
              ClassIdBean classIdBean = new ClassIdBean(interfaceClass, group, version);
              Object dubboReference =
                  DubboConsumerAutoConfiguration.DUBBO_REFERENCES_MAP.get(classIdBean);
              if (dubboReference == null) {
                synchronized (this) {
                  // double check
                  dubboReference =
                      DubboConsumerAutoConfiguration.DUBBO_REFERENCES_MAP.get(classIdBean);
                  if (dubboReference == null) {
                    referenceBean.afterPropertiesSet();
                    // dubboReference should not be null, otherwise it will cause
                    // NullPointerException
                    dubboReference = referenceBean.getObject();
                    DubboConsumerAutoConfiguration.DUBBO_REFERENCES_MAP.put(classIdBean,
                        dubboReference);
                  }
                }
              }
              field.setAccessible(true);
              field.set(bean, dubboReference);
            }
          }
        } catch (Exception e) {
          throw new BeanCreationException(beanName, e);
        }
        return bean;
      }

      @Override
      public Object postProcessAfterInitialization(Object bean, String beanName)
          throws BeansException {
        return bean;
      }
    };
  }

  /**
   * init consumer bean
   *
   * @param interfaceClazz interfaceClazz
   * @param reference reference
   * @return ReferenceBean<T>
   * @throws BeansException BeansException
   */
  private <T> ReferenceBean<T> getConsumerBean(String beanName, Field field, Reference reference)
      throws BeansException {
    ReferenceBean<T> referenceBean = new ReferenceBean<T>(reference);
    if ((reference.interfaceClass() == null || reference.interfaceClass() == void.class)
        && (reference.interfaceName() == null || "".equals(reference.interfaceName()))) {
      referenceBean.setInterface(field.getType());
    }

    Environment environment = this.applicationContext.getEnvironment();
    String application = reference.application();
    referenceBean.setApplication(this.parseApplication(application, this.properties, environment,
        beanName, field.getName(), "application", application));
    String module = reference.module();
    referenceBean.setModule(this.parseModule(module, this.properties, environment, beanName,
        field.getName(), "module", module));
    String[] registries = reference.registry();
    referenceBean.setRegistries(this.parseRegistries(registries, this.properties, environment,
        beanName, field.getName(), "registry"));
    String monitor = reference.monitor();
    referenceBean.setMonitor(this.parseMonitor(monitor, this.properties, environment, beanName,
        field.getName(), "monitor", monitor));
    String consumer = reference.consumer();
    referenceBean.setConsumer(this.parseConsumer(consumer, this.properties, environment, beanName,
        field.getName(), "consumer", consumer));

    referenceBean.setApplicationContext(DubboConsumerAutoConfiguration.this.applicationContext);
    return referenceBean;
  }

  @Override
  protected String buildErrorMsg(String... errors) {
    if (errors == null || errors.length != 4) {
      return super.buildErrorMsg(errors);
    }
    return new StringBuilder().append("beanName=").append(errors[0]).append(", field=")
        .append(errors[1]).append(", ").append(errors[2]).append("=").append(errors[3])
        .append(" not found in multi configs").toString();
  }
}

Returns an array of {@code Field} objects reflecting all the fields
declared by the class or interface represented by this
{@code Class} object. This includes public, protected, default
(package) access, and private fields, but excludes inherited fields.

 /**
     * Returns an array of {@code Field} objects reflecting all the fields
     * declared by the class or interface represented by this
     * {@code Class} object. This includes public, protected, default
     * (package) access, and private fields, but excludes inherited fields.
     *
     * <p> If this {@code Class} object represents a class or interface with no
     * declared fields, then this method returns an array of length 0.
     *
     * <p> If this {@code Class} object represents an array type, a primitive
     * type, or void, then this method returns an array of length 0.
     *
     * <p> The elements in the returned array are not sorted and are not in any
     * particular order.
     *
     * @return  the array of {@code Field} objects representing all the
     *          declared fields of this class
     * @throws  SecurityException
     *          If a security manager, <i>s</i>, is present and any of the
     *          following conditions is met:
     *
     *          <ul>
     *
     *          <li> the caller's class loader is not the same as the
     *          class loader of this class and invocation of
     *          {@link SecurityManager#checkPermission
     *          s.checkPermission} method with
     *          {@code RuntimePermission("accessDeclaredMembers")}
     *          denies access to the declared fields within this class
     *
     *          <li> the caller's class loader is not the same as or an
     *          ancestor of the class loader for the current class and
     *          invocation of {@link SecurityManager#checkPackageAccess
     *          s.checkPackageAccess()} denies access to the package
     *          of this class
     *
     *          </ul>
     *
     * @since JDK1.1
     * @jls 8.2 Class Members
     * @jls 8.3 Field Declarations
     */
    @CallerSensitive
    public Field[] getDeclaredFields() throws SecurityException {
        checkMemberAccess(Member.DECLARED, Reflection.getCallerClass(), true);
        return copyFields(privateGetDeclaredFields(false));
    }