I got Exception: Could not resolve class

[Øystein Myhre Andersen]

It was possible to implement a re-try loop solution.

But it did not turn out very pretty.


I would prefer a solution with implementing or instantiation of
'ClassHierarchyInfo'.


Here is the snippet code:



int count = 5;

while((count--) > 0) {

try {

byte[] bytes = ClassFile.of(ClassFile.ClassHierarchyResolverOption

.of(ClassHierarchy.getResolver())).build(CD_ThisClass,

... ... ...

);

return(bytes);

} catch(IllegalArgumentException e) {

boolean feasibleToReTry = false;

String msg = e.getMessage();

if(msg.startsWith("Could not resolve class")) {

String classID = msg.substring(24);

ClassDesc CD = ClassHierarchy.getClassDesc(classID);

if(CD != null) {

ClassHierarchyResolver resolver = ClassHierarchy.getResolver();

ClassHierarchyInfo classInfo = resolver.getClassInfo(CD);

feasibleToReTry = classInfo != null;

}

}

if(count <= 0 || !feasibleToReTry) throw e;

}



On Sat, Oct 19, 2024 at 8:16 AM Øystein Myhre Andersen <o.myhre at gmail.com>
wrote:

> But, it wasn't that simple !
>
> On Sat, Oct 19, 2024 at 8:04 AM Øystein Myhre Andersen <o.myhre at gmail.com>
> wrote:
>
>> I think I can solve the problem with a 're-try loop'.
>> Something like this:
>>
>> boolean done = false;
>>
>> while(! done) {
>>
>> try {
>>
>> byte[] bytes =
>> ClassFile.of(ClassFile.ClassHierarchyResolverOption.of(ClassHierarchy.getResolver())).build(CD_ThisClass,
>>
>>
>> ...
>>
>> done = true;
>>
>> return(bytes);
>>
>> } catch(Throwable e) {}
>>
>> }
>>
>> On Sat, Oct 19, 2024 at 7:44 AM Øystein Myhre Andersen <o.myhre at gmail.com>
>> wrote:
>>
>>> I tried to implement 'ClassHierarchyInfo' but I got "Sealed type
>>> ClassHierarchyInfo cannot be super type
>>> of MyClassHierarchyInfo as it is from a different package or split
>>> package or module"
>>>
>>>
>>> I misses a method to instantiate 'ClassHierarchyInfo' to deliver the
>>> result from 'getClassInfo'
>>>
>>>
>>> May be you should add a method like:
>>>
>>>
>>> 'static ClassHierarchyInfo of(ClassDesc subClass, ClassDesc superClass,
>>> boolean isInterface)'
>>>
>>>
>>> to the 'ClassHierarchyInfo'
>>>
>>>
>>> - Øystein
>>>
>>> On Fri, Oct 18, 2024 at 3:46 PM Chen Liang <chen.l.liang at oracle.com>
>>> wrote:
>>>
>>>> Thanks for sharing Oystein. The problem is that
>>>> ClassHierarchyResolver.of(Collection, Map) takes the immediate values in
>>>> the argument and ignores subsequent updates, which is how most ClassFile
>>>> APIs work, unfortunately. (The same thing happens if you try to do so for
>>>> AnnotationValue.OfArray or RuntimeVisibleAnnotationsAttribute)
>>>>
>>>> I recommend you return a ClassHierarchyResolver implementation of your
>>>> own, that returns the real-time results from your ClassHierarchy static
>>>> fields.
>>>>
>>>> Regards, Chen
>>>> ------------------------------
>>>> *From:* classfile-api-dev <classfile-api-dev-retn at openjdk.org> on
>>>> behalf of Øystein Myhre Andersen <o.myhre at gmail.com>
>>>> *Sent:* Friday, October 18, 2024 3:02 AM
>>>> *To:* Chen Liang <liangchenblue at gmail.com>
>>>> *Cc:* classfile-api-dev <classfile-api-dev at openjdk.org>
>>>> *Subject:* Re: I got Exception: Could not resolve class
>>>>
>>>> Here is the link:
>>>>
>>>> https://github.com/portablesimula/SimulaCompiler2/blob/main/Simula/src/simula/compiler/utilities/ClassHierarchy.java
>>>>
>>>> I use:
>>>> openjdk version "24-ea" 2025-03-18
>>>> OpenJDK Runtime Environment (build 24-ea+16-1800)
>>>> OpenJDK 64-Bit Server VM (build 24-ea+16-1800, mixed mode, sharing)
>>>>
>>>> - Øystein
>>>>
>>>> On Fri, Oct 18, 2024 at 9:51 AM Chen Liang <liangchenblue at gmail.com>
>>>> wrote:
>>>>
>>>> Hi Øystein, can you share a link to your ClassHierarchy code? ClassFile
>>>> API has a layer of caching for the ClassHierarchyResolver it uses, which
>>>> can lead to it not updating to the latest information in your
>>>> ClassHierarchy.
>>>>
>>>> Chen
>>>>
>>>> On Fri, Oct 18, 2024 at 2:40 AM Øystein Myhre Andersen <
>>>> o.myhre at gmail.com> wrote:
>>>>
>>>> Below is a snippet of my code:
>>>>
>>>>
>>>> public byte[] buildClassFile() {
>>>>
>>>> ClassDesc CD_ThisClass = currentClassDesc();
>>>>
>>>> ClassDesc CD_SuperClass = superClassDesc();
>>>>
>>>> ClassHierarchy.addClassToSuperClass(CD_ThisClass, CD_SuperClass);
>>>>
>>>> try {
>>>>
>>>> byte[] bytes =
>>>> ClassFile.of(ClassFile.ClassHierarchyResolverOption.of(ClassHierarchy.getResolver())).build(CD_ThisClass,
>>>>
>>>>
>>>> ...
>>>>
>>>> return(bytes);
>>>>
>>>> } catch(Throwable e) {
>>>>
>>>> ClassHierarchyResolver resolver = ClassHierarchy.getResolver();
>>>>
>>>> ClassDesc desc = ClassDesc.of("simulaFEC.CLASS_CHECKER1_semchecker1_exp
>>>> ");
>>>>
>>>> System.out.println("classInfo("+desc+") = " + resolver.getClassInfo(
>>>> desc));
>>>>
>>>>
>>>> e.printStackTrace();
>>>>
>>>> return null;
>>>>
>>>> }
>>>>
>>>> }
>>>>
>>>> When I run this code I get:
>>>>
>>>>
>>>> classInfo(ClassDesc[CLASS_CHECKER1_semchecker1_exp]) =
>>>> ClassHierarchyInfoImpl[superClass=ClassDesc[RTS_CLASS], isInterface=false]
>>>>
>>>> java.lang.IllegalArgumentException: Could not resolve class
>>>> CLASS_CHECKER1_semchecker1_exp
>>>>
>>>> at
>>>> java.base/jdk.internal.classfile.impl.ClassHierarchyImpl.resolve(ClassHierarchyImpl.java:76)
>>>>
>>>> at
>>>> java.base/jdk.internal.classfile.impl.ClassHierarchyImpl.isInterface(ClassHierarchyImpl.java:86)
>>>>
>>>> at
>>>> java.base/jdk.internal.classfile.impl.StackMapGenerator$Type.mergeReferenceFrom(StackMapGenerator.java:1334)
>>>>
>>>> .....
>>>>
>>>> I use my own 'resolver' which answers that 'CLASS_CHECKER1_semchecker1_
>>>> exp' is a subclass of 'RTS_CLASS'.
>>>>
>>>> I don't understand this.
>>>>
>>>>
>>>> - Øystein Myhre Andersen
>>>>
>>>>
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