在java中使用反射获取无效的类名

Question

我在代码中使用java反射，并在类中进行迭代。 在迭代中，我得到一个特定对象的无效类名。 PFB反射代码和我得到的日志

伐木工人：

2018-12-26 12:38:04,878 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- given class is : class com.paytm.oe.entity.RelatedBusinessSolutionMapping_$$_jvst3bb_5e
2018-12-26 12:38:04,879 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- fields are : private javassist.util.proxy.MethodHandler com.paytm.oe.entity.RelatedBusinessSolutionMapping_$$_jvst3bb_5e.handler
2018-12-26 12:38:04,879 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- fields are : public static byte[] com.paytm.oe.entity.RelatedBusinessSolutionMapping_$$_jvst3bb_5e._filter_signature
2018-12-26 12:38:04,879 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- fields are : public static final long com.paytm.oe.entity.RelatedBusinessSolutionMapping_$$_jvst3bb_5e.serialVersionUID
2018-12-26 12:38:04,879 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- fields are : private static java.lang.reflect.Method[] com.paytm.oe.entity.RelatedBusinessSolutionMapping_$$_jvst3bb_5e._methods_
2018-12-26 12:38:04,879 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- field is : handler path is : relatedBusinessSolutionMapping
2018-12-26 12:38:04,879 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- field is : _filter_signature path is : relatedBusinessSolutionMapping
2018-12-26 12:38:04,880 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- field is : serialVersionUID path is : relatedBusinessSolutionMapping
2018-12-26 12:38:04,880 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- field is : _methods_ path is : relatedBusinessSolutionMapping
2018-12-26 12:38:04,880 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- field is : solutionType path is : null
2018-12-26 12:38:04,880 INFO  [http-nio-8180-exec-4] [] [] [diy-CJ] []- Path in non-primitive type is : null for field : solutionType

您可以清楚地看到，记录器的第一行将类名打印为：com.paytm.oe.entity.RelatedBusinessSolutionMapping_$$_jvst3bb_5e 而应该是：

com.paytm.oe.entity.RelatedBusinessSolutionMapping

反射代码：

public static void setNullFieldInAnObject(Object object, Set<String> value, String path) throws Exception {
    LOGGER.info("In merge diff according to the given set function");
    LOGGER.info("Set is : " + value);
    LOGGER.info("Object is : " + object.toString());
    Class classA = object.getClass();
    LOGGER.info("given class is : " + classA.toString());
    Field fields[] = classA.getDeclaredFields();
    for (int i = 0; i < fields.length; i++) {
        LOGGER.info("fields are : " + fields[i].toString());
    }
}

只有在这种情况下，它给出了一个错误的类名，这会妨碍我在类内部进行迭代。对于所有其他情况，它工作正常。 请帮忙

Answer 1

正如在注释中指出的，代码失败的类不是因为类名错误，而是因为它是一个javaassist代理类。据我所知，javaassist仅通过创建子类来代理，因此如果您知道该类是代理，那么只需调用Class.getSuperclass()。为了检索原始类，javaassist代理都实现javassist Proxy接口，因此类似这样的东西可能会满足您的需要：

Class<?> classA = object.getClass();
if(javassist.util.proxy.Proxy.isAssignableFrom(classA)) {
    classA = classA.getSuperclass();
}

Answer 2

if (object instanceof HibernateProxy) {
            object = ((HibernateProxy) object).getHibernateLazyInitializer()
                    .getImplementation();
        }

这段代码对我有用

Answer 3

您的对象应该是由spring生成的动态代理目标（我猜，因为没有相关代码）

那你可以试试这个

Class clazz = AopUtils.getTargetClass(proxy);
Arrays.stream(clazz.getDeclaredFields()).forEach(field -> System.out.println(field.getName()));

AopUtils在org下。springframework。aop。支持