CODEWITHSUNDEEP
javalambdajava-8
Kevin Santos
Kevin Santos

Reputation: 21

convert lambda to function/method

I am trying to understand a program in java which has used lambda to return object into the reference variable of an interface. I want to convert lambda into simple java function, but not sure how to do it.

The program is as follows:-

public class AgentLicenseLazyModel extends CoreDataModel<AgentLicenseModel> {

    public AgentLicenseLazyModel(final List<AgentLicenseModel> entities) {
        super(AgentLicenseModel.class, entities, (sortField, sortOrder) -> {
            return new AgentLicenseLazySorter(sortField, sortOrder);
        });
    }
}

Here is the abstract class: 

public abstract class CoreDataModel<T extends AbstractEntityModel> extends LazyDataModel<T> {

private final Class<T> entityClass;
private final List<T> entities;
private final CoreDataSorterProducer<T> coreDataSorterProducer;

public CoreDataModel(final Class<T> entityClass, final List<T> entities, final CoreDataSorterProducer<T> coreDataSorterProducer) {
    this.entityClass = entityClass;
    this.entities = entities;
    this.coreDataSorterProducer = coreDataSorterProducer;

    if (entities != null) {
        setRowCount(entities.size());
    }
}

How to convert this program into simple java program without use of lambda for learning. Please help.

Edited: Here is the CoreDataSorterProducer:

@FunctionalInterface
public interface CoreDataSorterProducer<T extends AbstractEntityModel> {

    CoreDataSorter<T> produce(String sortField, SortOrder sortOrder);
}

Upvotes: 1

Views: 1334

Answers (1)

Eran
Eran

Reputation: 394016

The body of the lambda expression is the implementation of the single abstract method of the CoreDataSorterProducer<AgentLicenseModel> interface.

You can replace the lambda expression with an anonymous classs instance that implements CoreDataSorterProducer<AgentLicenseModel>. 

public class AgentLicenseLazyModel extends CoreDataModel<AgentLicenseModel> {
    public AgentLicenseLazyModel(final List<AgentLicenseModel> entities) {
        super(AgentLicenseModel.class, entities, new CoreDataSorterProducer<AgentLicenseModel> () {

            public AgentLicenseLazySorter theMethodName (TheTypeOfSortField sortField, TheTypeOfSortOrder sortOrder) 
            {
                return new AgentLicenseLazySorter(sortField, sortOrder);
            }
        });
    }
}

Note that theMethodName, TheTypeOfSortField and TheTypeOfSortOrder should be replaced by the method name of the CoreDataSorterProducer interface and the types of its arguments.

Upvotes: 7

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