se.hiq.oss.commons.reflection.collection.ClassMap Maven / Gradle / Ivy
Show all versions of commons-reflection Show documentation
package se.hiq.oss.commons.reflection.collection;
import java.util.HashMap;
import java.util.Map;
/**
* Wraps a map and resolves super classes and / or interfaces of the key.
*
* {@code
* Map, String> map = new HashMap, String>();
* map.put(java.lang.Object.class, "Object");
* map.put(java.lang.Integer.class, "Integer")
* ClassMap classMap = new ClassMap();
* classMap.setMap(map);
* String doubleString = classMap.get(java.lang.Double);
* assert(doubleString.equals("Object"))
* String numberString = classMap.get(java.lang.Number);
* assert(numberString.equals("Object"))
* String integerString = classMap.get(java.lang.Integer);
* assert(numberString.equals("Integer"))
* }
*
* @param Content type of the map
* @author rikardwi
**/
public class ClassMap {
private Map, T> map = new HashMap, T>();
public ClassMap() {
}
public ClassMap(final Map, T> map) {
this.map.putAll(map);
}
/**
* Returns the value of a map entry which key matches the supplied class
* or any of its super classes or any of its interfaces.
*
* Values are resolved using the most specific classes and interfaces first
* and then more general (base classes).
*
* @param clazz Class to resolve value for by inspecting the class META data.
* @return value found for the supplied class or null if no value could be resolved.
**/
public T get(final Class clazz) {
Class classToInspect = clazz;
T object = map.get(classToInspect);
if (object == null) {
object = getByInterfaces(classToInspect);
}
while (object == null && classToInspect.getSuperclass() != null) {
classToInspect = classToInspect.getSuperclass();
object = map.get(classToInspect);
if (object == null) {
object = getByInterfaces(classToInspect);
}
}
return object;
}
/**
* Returns the value associated with the any
* interface implemented by the supplied class.
*
* This method will return the first match only, if
* more than one value can be resolved the first is
* returned.
*
* @param clazz Class to inspect interfaces of.
* @return The resolved value if found, else null.
**/
public T getByInterfaces(final Class clazz) {
T object = null;
Class[] interfaces = clazz.getInterfaces();
for (Class interfaceClass : interfaces) {
object = map.get(interfaceClass);
if (object != null) {
break;
}
}
return object;
}
}