How retrieve all classes that implement one or more interfaces

To find all classes that implement one or more interfaces we are going to use the ClassHunter. Before starting keep in mind that if you need help you can ask the Burningwave community for assistance. In the following example we are going to look for all classes that implement java.io.Closeable or java.io.Serializable interface:

import java.io.Closeable;
import java.io.Serializable;
import java.util.Collection;

import org.burningwave.core.assembler.ComponentContainer;
import org.burningwave.core.assembler.ComponentSupplier;
import org.burningwave.core.classes.ClassCriteria;
import org.burningwave.core.classes.ClassHunter;
import org.burningwave.core.classes.SearchConfig;

public class Finder {
    
    public Collection<Class<?>> simplifiedFind() {

        ComponentSupplier componentSupplier = ComponentContainer.getInstance();
        ClassHunter classHunter = componentSupplier.getClassHunter();
        
        //With this the search will be executed on default configured paths that are the 
        //runtime class paths plus, on java 9 and later, the jmods folder of the Java home.
        //The default configured paths are indicated in the 'paths.hunters.default-search-config.paths'
        //property of burningwave.properties file (see Architectural overview and configuration)
        try (ClassHunter.SearchResult searchResult = classHunter.findBy(
                SearchConfig.byCriteria(
                    ClassCriteria.create().allThoseThatMatch(currentScannedClass ->
                        Closeable.class.isAssignableFrom(currentScannedClass) ||
                        Serializable.class.isAssignableFrom(currentScannedClass)
                    )
                )
            )) {
            return searchResult.getClasses();
        }
    }

}

It is also possible to expressly indicate the paths on which to search:

import java.io.Closeable;
import java.io.Serializable;
import java.util.Collection;

import org.burningwave.core.assembler.ComponentContainer;
import org.burningwave.core.assembler.ComponentSupplier;
import org.burningwave.core.classes.ClassCriteria;
import org.burningwave.core.classes.ClassHunter;
import org.burningwave.core.classes.SearchConfig;
import org.burningwave.core.io.PathHelper;

public class Finder {

    public Collection<Class<?>> find() {
        ComponentSupplier componentSupplier = ComponentContainer.getInstance();
        PathHelper pathHelper = componentSupplier.getPathHelper();
        ClassHunter classHunter = componentSupplier.getClassHunter();

        SearchConfig searchConfig = SearchConfig.forPaths(
            pathHelper.getPaths(path -> path.contains("spring-core-4.3.4.RELEASE.jar"))
        ).by(
            ClassCriteria.create().byClassesThatMatch((uploadedClasses, currentScannedClass) ->
                //[1]here you recall the uploaded class by "useClasses" method.
                //In this case we're looking for all classes that implement java.io.Closeable or java.io.Serializable
                uploadedClasses.get(Closeable.class).isAssignableFrom(currentScannedClass) ||
                uploadedClasses.get(Serializable.class).isAssignableFrom(currentScannedClass)
            ).useClasses(
                //With this directive we ask the library to load one or more classes to be used for comparisons:
                //it serves to eliminate the problem that a class, loaded by different class loaders, 
                //turns out to be different for the comparison operators (eg. The isAssignableFrom method).
                //If you call this method, you must retrieve the uploaded class in all methods that support this feature like in the point[1]
                Closeable.class,
                Serializable.class
            )
        );

        try (ClassHunter.SearchResult searchResult = classHunter.findBy(searchConfig)) {
            return searchResult.getClasses();
        }
    }

}