java - CtClass.toClass 抛出异常，消息为 'null'

Question

创建动态类的步骤如下:

      try
      {

            classLoader = Class.forName("org.yaddayadda.DynamicClass" + genericType.getName().toLowerCase() + uniqueID);
        }
        catch (ClassNotFoundException classNotFoundException)
        {
        }

        if (classLoader == null)
        {
            dynamicClass = pool.get("org.yaddayadda.DynamicClass");
            dynamicClass.defrost();
            dynamicClass.replaceClassName("org.yaddayadda.DynamicClass","org.yaddayadda.DynamicClass"+ genericType.getName().toLowerCase() + uniqueID);

            dynamicClass.defrost();


            CtMethod readObject = dynamicClass.getDeclaredMethod("Method1");
            CtMethod writeObject = dynamicClass.getDeclaredMethod("Method2");

            StringBuffer method1= new StringBuffer();
            StringBuffer method2= new StringBuffer();

            GenerateDynamicCode.generateCode(genericType, method1, method2);

            writeObject.insertAt(1, method1.toString());
            readObject.insertAt(1, method2.toString());

            //This is where the exception is thrown
            classLoader = dynamicClass.toClass();
        }

我首先尝试检查该类是否已存在于 ClassPool 中，如果不存在，我将继续创建一个类。除霜只是为了一种故障安全机制。当方法 toClass 被调用时出现异常 dynamicClass.toClass();

异常如下

    Exception Message: null
    Stack Trace: 
    sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    javassist.ClassPool.toClass2(ClassPool.java:1102)
    javassist.ClassPool.toClass(ClassPool.java:1083)
    javassist.ClassPool.toClass(ClassPool.java:1032)
    javassist.ClassPool.toClass(ClassPool.java:990)
    javassist.CtClass.toClass(CtClass.java:1125)
    This Class

出现上述异常的原因是什么，如何避免？

Answer 1

好吧，我找到了一个解决方案，实际上是一个解决方法，即我只是简单地再次调用一个循环来解冻已编译的类并重做我刚刚尝试的一切，当出现异常并且循环最多运行 3 次只是为了安全侧面

        int i = 0;
        while (classLoader == null)
        {
            try
            {
                if (classLoader == null)
                {
                    dynamicClass = pool.get("org.yaddayadda.DynamicClass");
                    dynamicClass.defrost();


                    try
                    {
                        dynamicSurrugate = pool.get("org.yaddayadda.DynamicClass" + genericType.getName().toLowerCase() + uniqueID);

                        dynamicSurrugate.defrost();
                    }
                    catch (NotFoundException notFoundException)
                    {
                    }


                    //Everything the same
                }
            }
            catch (Exception exception)
            {
                classLoader = null;
                i++;
            }

            if (i == 3)
            {
                throw new Exception("IF failed throw message third time");
            }
        }