Java 还使用了如何将空值传递给pojo属性，以便使用Jackson和Spring AOP转换为Json

我试图在春季使用jacksonjar返回一个json。但我在转换相同内容时出错。这个错误与SpringAOP有关，因为当我删除它时，代码工作正常。请查看以下pojo详细信息：-

//@JsonInclude(JsonInclude.Include.NON_NULL)
 @JsonInclude(content=JsonInclude.Include.NON_EMPTY) 
 public class UserBean {

   private String result;
   private String tID;

  //getters and setters

}

我已经在类级别尝试了上述两种注释

在上面的代码中，我只在TID字段中设置值，结果字段的默认值为null。这个java类中还有一个ToString方法

控制器类：-

@Autowired
public UserBean userBean;

userBean.settID("T123456");

xml->

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.7.3</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.5.4</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.7.3</version>
    </dependency>

这就是我得到的错误->

 Could not write content: 
    No serializer found for class org.springframework.aop.TrueClassFilter
    and no properties discovered to create BeanSerializer 
    (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) 
    (through reference chain: com.fca.c2pc.bean.UserBean$$EnhancerBySpringCGLIB$$c56dc6af
["advisors"]->org.springframework.aop.interceptor.["pointcut"]->
   org.springframework.aop.TruePointcut["classFilter"]); 
   nested exception is com.fasterxml.jackson.databind.JsonMappingException: 
No serializer found for class org.springframework.aop.TrueClassFilter and 
   no properties discovered to create BeanSerializer 
   (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) 
   (through reference chain: com.fca.c2pc.bean.UserBean$$EnhancerBySpringCGLIB$$c56dc6af
["advisors"]->org.springframework.aop.interceptor.["pointcut"]->
   org.springframework.aop.TruePointcut["classFilter"])

---

为什么你的

UserBean

甚至是一个spring管理的bean？那么它应该是什么呢？？除了我得到的例外，这又有什么关系呢？只有Springbean应用了AOP，如果它不是Springbean，它就不会用AOP来丰富，因此应该可以消除您的错误。不是所有的东西都必须是春豆…谢谢你的回复。。但例如，我的UserBean类有一个其他类或服务的引用，需要向spring容器注册。那么，为了使上述代码正常工作，应该在代码中进行哪些更改。为什么要将应用程序bean公开为JSON，您应该公开资源……为什么您的

UserBean

甚至是spring管理的bean？那么应该是什么呢？？除了我得到的例外，这又有什么关系呢？只有Springbean应用了AOP，如果它不是Springbean，它就不会用AOP来丰富，因此应该可以消除您的错误。不是所有的东西都必须是春豆…谢谢你的回复。。但例如，我的UserBean类有一个其他类或服务的引用，需要向spring容器注册。那么，为了使上述代码正常工作，应该在代码中做哪些更改呢。。。

public class LogginAspect {

    private static final Logger logger = Logger.getLogger(LogginAspect.class);

    @After("execution(* com.fca.c2pc..*.*(..))")
    public void logAfter(JoinPoint joinPoint) {

        logger.info("After executing method : " + joinPoint.getSignature().getName());
        logger.info("***************************************************************************");
    }

    @Before("execution(* com.fca.c2pc..*.*(..))")
    public void logBefore(JoinPoint joinPoint) {

        logger.info("***************************************************************************");
        logger.info("Before executing method : " + joinPoint.getSignature().getName());
    }

    @Around("execution(* com.fca.c2pc..*.*(..))")
    public Object logAround(ProceedingJoinPoint pjp) throws Throwable {

        long start = System.currentTimeMillis();
        Object clazz = pjp.getTarget().getClass().getName();
        String methodName = pjp.getSignature().getName();
        logger.info("Entering Class " + clazz + " With Method Name " + methodName);
        Object[] obj = pjp.getArgs();
        int i = 0;
        try {
            for (Object o : obj) {
                logger.info(++i + " : Parameter Name :" + (null != o ? o.toString() : ""));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        Object output = pjp.proceed(pjp.getArgs());

        logger.info("Excecution Completed for method : " + methodName + " in Class : " + clazz + " with result "
                + output);
        long elapsedTime = System.currentTimeMillis() - start;
        logger.info("Execution time for method : " + methodName + " in Class : " + clazz + " : " + elapsedTime
                + " milliseconds.");
        return output;
    }

    @AfterThrowing(pointcut = "execution(* com.fca.c2pc..*.*(..))", throwing = "error")
    public void logAfterThrowing(JoinPoint joinPoint, Throwable error) {

        logger.info("Exception thrown by method : " + joinPoint.getSignature().getName());
        logger.info("Exception name : " + error);
    }

    @AfterReturning(pointcut = "execution(* com.fca.c2pc..*.*(..))", returning = "result")
    public void logAfterReturning(JoinPoint joinPoint, Object result) {

        logger.info("Method : " + joinPoint.getSignature().getName() + " returned value is : " + result);
    }

 Could not write content: 
    No serializer found for class org.springframework.aop.TrueClassFilter
    and no properties discovered to create BeanSerializer 
    (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) 
    (through reference chain: com.fca.c2pc.bean.UserBean$$EnhancerBySpringCGLIB$$c56dc6af
["advisors"]->org.springframework.aop.interceptor.["pointcut"]->
   org.springframework.aop.TruePointcut["classFilter"]); 
   nested exception is com.fasterxml.jackson.databind.JsonMappingException: 
No serializer found for class org.springframework.aop.TrueClassFilter and 
   no properties discovered to create BeanSerializer 
   (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS) ) 
   (through reference chain: com.fca.c2pc.bean.UserBean$$EnhancerBySpringCGLIB$$c56dc6af
["advisors"]->org.springframework.aop.interceptor.["pointcut"]->
   org.springframework.aop.TruePointcut["classFilter"])