com.alibaba.fastjson.JSONException: safeMode not support autoType : com.*.common.core.domain.User

通过fastjson反序列化某javabean时失败，并抛出以下异常：

Could not deserialize: autoType is not support. com.xxx.Shop; nested exception is com.alibaba.fastjson.JSONException: autoType is not support. com.xxx.Shop     at com.alibaba.fastjson.support.spring.GenericFastJsonRedisSerializer.deserialize(GenericFastJsonRedisSerializer.java:37)

然而只有项目第一次反序列化该javabean时会抛异常失败，复现方式只有重启项目后的第一次反序列化操作。 过程

查询官方文档，开启AutoType的方法 enable_autotype。

但是文档中的方法均测试无效，无奈debug源码，发现抛出异常的代码为 com.alibaba.fastjson.parser.ParserConfig的1125行代码：

JavaBeanInfo beanInfo = JavaBeanInfo.build(clazz, clazz, propertyNamingStrategy); if (beanInfo.creatorConstructor != null && autoTypeSupport) {     throw new JSONException("autoType is not support. " + typeName); }

经与正常反序列化的javabean比较后，发现反序列化失败的javabean在如上代码执行时，beanInfo.creatorConstructor的值不为null，最后抛出autoType is not support的异常。

继续追踪，在com.alibaba.fastjson.util.JavaBeanInfo283行代码判断反序列化失败的javabean为接口或抽象类：

boolean isInterfaceOrAbstract = clazz.isInterface() || Modifier.isAbstract(clazz.getModifiers());

再于com.alibaba.fastjson.util.JavaBeanInfo381行代码的if判断分支下给beanInfo.creatorConstructor赋值：

else if (!isInterfaceOrAbstract){     ...     for (Constructor constructor : constructors) {         Class[] parameterTypes = constructor.getParameterTypes();            if (className.equals("org.springframework.security.web.authentication.WebAuthenticationDetails")) {             if (parameterTypes.length == 2 && parameterTypes[0] == String.class && parameterTypes[1] == String.class) {                 creatorConstructor = constructor;                 creatorConstructor.setAccessible(true);                 paramNames = ASMUtils.lookupParameterNames(constructor);                 break;             }         }              if (className.equals("org.springframework.security.web.authentication.preauth.PreAuthenticatedAuthenticationToken")) {             if (parameterTypes.length == 3                     && parameterTypes[0] == Object.class                     && parameterTypes[1] == Object.class                     && parameterTypes[2] == Collection.class) {                 creatorConstructor = constructor;                 creatorConstructor.setAccessible(true);                 paramNames = new String[] {"principal", "credentials", "authorities"};                 break;             }         }              if (className.equals("org.springframework.security.core.authority.SimpleGrantedAuthority")) {             if (parameterTypes.length == 1                     && parameterTypes[0] == String.class) {                 creatorConstructor = constructor;                 paramNames = new String[] {"authority"};                 break;             }         }              boolean is_public = (constructor.getModifiers() & Modifier.PUBLIC) != 0;         if (!is_public) {             continue;         }         String[] lookupParameterNames = ASMUtils.lookupParameterNames(constructor);         if (lookupParameterNames == null || lookupParameterNames.length == 0) {             continue;         }              if (creatorConstructor != null                 && paramNames != null && lookupParameterNames.length