I have two classes org.my.ClassA and org.my.ClassB both classes are in the same package org.my in the WEB-INF/src in the same database.
ClassA has the method public add(org.my.ClassB newB){...}.
In SSJS I have a code block in which I call ClassA.add(ClassB) which normally works fine. Until some unknown point where the Server can't see that org.my.ClassB === org.my.ClassB and it returns the error (message translated from German maybe looks different in English version):
error calling method 'add(org.my.ClassB)' in java-class 'ClassA'.
'org.my.ClassB' is incompatible with 'org.my.ClassB'.
and it points to my line in the SSJS: ClassA.add(ClassB);
What I tried so far:
First I added the line importPackage(org.my); to my SSJS Code. No luck.
I tried to add another method add(Object newB) and then cast the object to ClassB but same result. The error does not seem to come from the java class its from the SSJS code because it cant find the method with an argument of the type org.my.ClassB. But if I test the object in the SSJS code it returns org.my.ClassB.
Then I tried to add the classpath to all variables in the SSJS block like: var newB:org.my.ClassB = new org.my.ClassB(). But same result after some time the application breaks with the same error.
From my Point of view it got to do something with the caching of compiled classes, or so because if I clear the database everything works just fine again.
Hope someone has a solution on this.
This is a class loader problem.
You can find more details about the issue in the answer from Frantisek Kossuth:
See here more details: Meaning of java.lang.ClassCastException: someClass incompatible with someClass
Related
As my training goes on, I've come accross this BaseApiClass without parameterless constructor, so when I'm inhereting the base class, I always pass the required parameter. But on run time I got an error like this:
Note: I've noticed that they're using Autofac but I'm not familiar with that..
Here's what the api controller looks like:
and base class:
I tried adding parameterless constructor but it obviously throws error because it doesn't correspond to my baseclass.
Here's what my Global.asax looks like:
I'm kind of new to this. Any suggestion would be great!
I'm working with Acumatica 5.30.2347. I have following selector in my graph:
var check = PXSelect<POLine,Where<POLine.orderType, Equal<POOrderType.regularOrder>>>
.Select(this);
but when I try to execute it, I receive following error:
Method not found: 'Void PX.Data.PXLineAttribute..ctor'(System.Type).
Initially I've got an impression, that this error message appeared because class PXLineAttribute doesn't have constructor which accepts System.Type, but with help of reflector I've discovered that PXLineAttribute has following declaration:
public PXLineNbrAttribute(System.Type sourceType)
: this(sourceType, false)
{
}
which gives me idea that PXLineNbrAttribute has needed constructor. So I have two questions: Why Acumatica Framework can't find constructor of PXLineNbrAttribute? How to help Acumatica to find before mentioned constructor?
Please check your VS class library project references to Acumatica assemblies. I would suspect them to reference assemblies from a different Acumatica build and therefore cause "Method not found ..." errors at runtime.
I am trying to load some object through bytecode modification using asm bytecode instrumentation library.
I am retransforming the classes using retransformClasses() method.
I am loading the objects in this way :
super.visitVarInsn(Opcodes.ALOAD, 0);
super.visitFieldInsn(Opcodes.GETFIELD, owner, name, desc);
super.visitMethodInsn(org.objectweb.asm.Opcodes.INVOKESTATIC,
"com/coolcoder/MyClass",
"objectCheckTest",
"(Ljava/lang/Object;)V");`
The problem is that I the objects are getting loaded using usual tranform() of ClassTransformer , but when I am using Attach API's retranformClasses() , these objects are not getting loaded . Strange thing is that , I am not getting any bytecode error either.
Am I doing something wrong ? or am I missing some intricate part regarding retransform ?
I was be able to solve the issue , though I do not know why it happened in the first place.
(1) I was loading the object only on PUTFIELD or PUTSTATIC opcodes, i.e , when the object value is being set.
(2) Just after bytecode modification the class is getting redefined , as a result of which the code snippet did not work.
(3) Next time when the class loaded due to redefinition , the object is already being set , so it will not be called again.
(4) Now , when I checked for GETFIELD or GETSTATIC opcodes , i.e when the object's value is being retrieved and I loaded it , I was able to view its details.
The same approach which I mentioned above is working fine in usual transformation (i.e running with premain).
Any idea on this erratic behaviour of redefinition ?
First, in manifest.mf file,Can-Retransform-Classes attribute should be true.
And your ClassFileTransformer instance should be add with the true value for parameter canRetransform in method addTransformer .
Here is another additional tips:
If the transformer throws an exception (which it doesn't catch), subsequent transformers will still be called and the load, redefine or retransform will still be attempted. Thus, throwing an exception has the same effect as returning null. To prevent unexpected behavior when unchecked exceptions are generated in transformer code, a transformer can catch Throwable. If the transformer believes the classFileBuffer does not represent a validly formatted class file, it should throw an IllegalClassFormatException; while this has the same effect as returning null. it facilitates the logging or debugging of format corruptions.
from java api docs
So, there maybe some uncatched exception which will be just ignored by the jvm arised.
You can put a try..catch
Please forgive my poor English ...
I have a app where my users input a HTML template with SimpleTemplateEngine notation, and execute this template with code above, in a Java Class:
new SimpleTemplateEngine().createTemplate(templateStr).make(map).toString()
and I obtain this error:
groovy.lang.GroovyRuntimeException: Could not instantiate custom Metaclass for class: java.util.ArrayList. Reason: java.lang.NoSuchMethodException: groovy.runtime.metaclass.java.util.ArrayListMetaClass.<init>(groovy.lang.MetaClass)
I observe that error occurrs in a loop in a java.util.ArrayLIst in a JPA Entity loaded by Hibernate:
<%for(int k=0; k< Registro[i].listUsers.size();k++){%>
HTML CODE
<%}%>
Anyone can help me? I no have more ideas about this error...
Thanks!
I'm guessing that the part Registro[i] is for getting the value of a static property which name is held under the variable i (or at least that is what will happen) unless the getAt(String) method has been overloaded on Registro.
Either way I also guess that returns an object that has a listUsers property that should be at least a Collection.
Maybe the problem is with the initialization of said listUsers property.
Some Registro code could be used for better understanding.
I have a question that keeps bothering me. Currently, I have started using Kohana 3.2 Framework. I've written a helper to handle some functionality - I have a number of methods, which are (as it should be) declared STATIC. But, all of these methods are somehow working with the database, so I need to load a model. Currently, every method has a non-static variable like this:
$comment = new Model_Comments;
$comment->addComment("abc");
OK, it seems to be working, but then I wanted to get rid of this redundancy by using class attribute to hold the instance of the model (with is class as well).
Something like this:
private static $comment; // Declaring attribute
self::$comment = new Model_Comment; // This is done within helper __constuct method
self::$comment->addComment("abc"); // And call it within the method.
But, I got failed with: Call to a member function addComment() on a non-object
Question is: is it possible to do it ? Maybe there are some other approaches ?
Sorry for a long story and, thanks in advice! :P
A static method cannot call a non-static method without operating on an instance of the class. So, what you're proposing won't work. There may be a way do accomplish something similar, but what about trying the following:
You could implement the singleton or factory pattern for your "helper" class. Then, you could create the model (as an attribute) as you instantiate/return the instance. With an actual instance of your "helper" class, you won't have to worry about the static scope issues.
In other words, you can create a helper-like class as a "normal" class in your application that, upon creation, always has the necessary model available.
I'd be happy to help further if this approach makes sense.
David