摘要：同時注釋配置失敗的構造方法觸發(fā)了兩次，添加到中的實例和注冊到容器中的實例并不是同一個實例解決方法增加一個獲取的實例的工具類，通過這個工具類調(diào)用需要注入的服務的方法工具類修改攔截器執(zhí)行結(jié)果

JDK 1.8

Springboot 2.1.1.RELEASE

    
        org.springframework.boot
        spring-boot-starter-parent
        2.1.1.RELEASE
         
    
    
    
        
            org.springframework.boot
            spring-boot-starter-data-jpa
        

        
            mysql
            mysql-connector-java
            8.0.13
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        
    

@Entity
public class User implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    private String name;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

public interface UserRepository extends JpaRepository {

}

@Service
public class MyService {

    public void print(){
        System.out.println(this.getClass().getSimpleName()+" call");
    }
}

public class SimpleInterceptor extends EmptyInterceptor {

    @Resource
    private MyService myService;

    @Override
    public String onPrepareStatement(String sql) {
        myService.print();
        System.out.println("sql:"+sql);
        return super.onPrepareStatement(sql);
    }
}

@SpringBootApplication
public class BootHibernateInterceptorProblemApplication {

    public static void main(String[] args) {
        SpringApplication.run(BootHibernateInterceptorProblemApplication.class, args);
    }

}

## DataSource
spring.datasource.url=jdbc:mysql://localhost:3306/demo?characterEncoding=utf8&useSSL=true
spring.datasource.username=root
spring.datasource.password=123456789

## hibernate
spring.jpa.hibernate.ddl-auto=update
## add interceptor
spring.jpa.properties.hibernate.ejb.interceptor=com.rjh.interceptor.SimpleInterceptor

@RunWith(SpringRunner.class)
@SpringBootTest
public class BootHibernateInterceptorProblemApplicationTests {

    @Resource
    private UserRepository userRepository;

    @Test
    public void contextLoads() {
        System.out.println(userRepository.findAll());
    }

}

java.lang.NullPointerException
    at com.rjh.interceptor.SimpleInterceptor.onPrepareStatement(SimpleInterceptor.java:20)
    ...
    ...
    ...

根據(jù)異常信息，猜測是注入MyService失敗

@RunWith(SpringRunner.class)
@SpringBootTest
public class BootHibernateInterceptorProblemApplicationTests {

    @Resource
    private UserRepository userRepository;

    @Resource
    private MyService myService;

    @Resource
    private SimpleInterceptor simpleInterceptor;

    @Test
    public void contextLoads() {
        Assert.assertNotNull(myService);
        Assert.assertNotNull(simpleInterceptor);
        System.out.println(userRepository.findAll());
    }

}

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type "com.rjh.interceptor.SimpleInterceptor" available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@javax.annotation.Resource(shareable=true, lookup=, name=, description=, authenticationType=CONTAINER, type=class java.lang.Object, mappedName=)}
    ...

根據(jù)異常信息可知，Spring的IoC容器中并沒有SimpleInterceptor這個Bean，從此處可知spring.jpa.properties.hibernate.ejb.interceptor=com.rjh.interceptor.SimpleInterceptor并沒有把這個攔截器注冊到Spring容器中

在SimpleInterceptor上添加@Component注解，將SimpleInterceptor注冊到Spring容器中。同時注釋spring.jpa.properties.hibernate.ejb.interceptor配置

失敗：SimpleInterceptor的構造方法觸發(fā)了兩次，添加到Hibernate中的SimpleInterceptor實例和注冊到Spring容器中的SimpleInterceptor實例并不是同一個實例

增加一個獲取Spring的ApplicationContext實例的工具類，通過這個工具類調(diào)用需要注入的服務的方法

@Component
public class SpringContextUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextUtil.applicationContext=applicationContext;
    }

    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }
}

public class SimpleInterceptor extends EmptyInterceptor {

    @Override
    public String onPrepareStatement(String sql) {
        MyService myService= SpringContextUtil.getApplicationContext().getBean(MyService.class);
        myService.print();
        System.out.println("sql:"+sql);
        return super.onPrepareStatement(sql);
    }

}

MyService call
sql:select user0_.id as id1_0_, user0_.name as name2_0_ from user user0_
[]