info.unterrainer.commons.jreutils.Reflecting Maven / Gradle / Ivy
package info.unterrainer.commons.jreutils;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import lombok.experimental.UtilityClass;
@UtilityClass
public class Reflecting {
/**
* Scans object tree connected by annotated fields for a given class using
* reflection and returns found paths.
*
* @param classToScan the class to start scanning in
* @param fieldTypeToFind the type to search for
* @param annotationToScanFor the annotation the fields we should scan are
* annotated with
* @return a list of paths where the given fields have been found
*/
public List getPathsOf(final Class classToScan, final Class fieldTypeToFind,
final Class annotationToScanFor) {
return getPathsOf(classToScan, fieldTypeToFind, annotationToScanFor, "");
}
private List getPathsOf(final Class classToScan, final Class typeToFind,
final Class annotation, final String currentPath) {
List paths = new ArrayList<>();
for (Field field : classToScan.getDeclaredFields()) {
Class currentType = field.getType();
if (field.isAnnotationPresent(annotation)) {
if (typeToFind.isAssignableFrom(currentType)) {
paths.add(currentPath + field.getName());
continue;
}
paths.addAll(getPathsOf(currentType, typeToFind, annotation, currentPath + field.getName() + "."));
}
}
return paths;
}
/**
* Gets the instance of a specific field given by path.
*
* @param the type of the field to find
* @param path The path to follow in order to get to the field
* @param instanceToSearchIn the instance of the object to search for the field
* in
* @param annotationToScanFor the annotation that leads to the field to find
* @return the field
* @throws IllegalArgumentException if the specified object is not an instance
* of the class or interface declaring the
* underlying field (or a subclass or
* implementor thereof).
* @throws IllegalAccessException if this Field object is enforcing Java
* language access control and the underlying
* field is inaccessible.
*/
public T getFieldByPath(final String path, final Object instanceToSearchIn,
final Class annotationToScanFor)
throws IllegalArgumentException, IllegalAccessException {
FieldParser p = new FieldParser(path, instanceToSearchIn, annotationToScanFor);
return p.parse();
}
}