Call AWS Batch meter Generic API

I have to call AWS batch meter API which is generic. When I am calling this function I am getting an error. Please help how to call a generic API

public <T> Optional<T> getValueForField(String fieldName, Class<T> clazz) {
        byte var4 = -1;
        switch(fieldName.hashCode()) {
        case -1532767274:
            if (fieldName.equals("Results")) {
                var4 = 0;
            }
            break;
        case 743387085:
            if (fieldName.equals("UnprocessedRecords")) {
                var4 = 1;
            }
        }

        switch(var4) {
        case 0:
            return Optional.ofNullable(clazz.cast(this.results()));
        case 1:
            return Optional.ofNullable(clazz.cast(this.unprocessedRecords()));
        default:
            return Optional.empty();
        }
    }

public List<UsageRecordResult> results() {
        return this.results;
    }

Calling Above API

batchMeterUsageResponse.getValueForField(RESULT, (Class<List<UsageRecordResult>>) new ArrayList<>().getClass());

Error i am getting :

Error:(98, 175) java: incompatible types: java.lang.Class<capture#1 of ? extends java.util.ArrayList> cannot be converted to java.lang.Class<java.util.List<software.amazon.awssdk.services.marketplacemetering.model.UsageRecordResult>>

TL;DR — If my assumption about the intention of your code is correct, then the simplest solution is demonstrated here…

...
Optional< List > wtTF = batchMeterUsageResponse.getValueForField( RESULTS, List.class );
...

To execute the code shown above, click the green Start button at the top of this IDE.

The long answer

BatchMeterUsageResult has a getResults() method and a getUnprocessedRecords() method that look like the same methods you have in your question. So my proposed fix above assumes that the intention of your sample code, is to return either a List<UsageRecordResult> or a List<UsageRecord>; depending on the value of fieldName.hashCode.

> „Error i am getting :“

> Error:(98, 175) java: incompatible types: java.lang.Class<capture#1 of ? extends java.util.ArrayList> cannot be converted to java.lang.Class<java.util.List<software.amazon.awssdk.services.marketplacemetering.model.UsageRecordResult>>

The error message is telling you that your attempt to cast from one type of Class<List<E>> to a different type of Class<List<E>>, failed.

The compiler knows the Class type of new ArrayList<>().getClass() to be Class<capture#1 of ? extends java.util.ArrayList>. You are trying to cast that to Class<List<UsageRecordResult>>.

The compiler cannot do the conversion because the two Class types are incompatible. The underlying reason they are incompatible is because List<UsageRecordResult> does not meet the criteria of: extends java.util.ArrayList. Remember: The interface List<E> is the superclass of ArrayList<E>. And as you know, it's impossible to assign a superclass to a subclass.

But that's only the first part of the problem with your code. The details of the other problems probably won't be as interesting to you as the above solution to make your code compile.

If my assumption about your code's intention is incorrect, then please edit your question with a clearer explanation of the actual intention of your code? TIA.