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Jodd BeanUtil is fast and powerful bean manipulation library.

There is a newer version: 5.1.6

// Copyright (c) 2003-2013, Jodd Team (jodd.org). All Rights Reserved.

package jodd.introspector;

import jodd.util.ref.ReferenceMap;
import jodd.util.ref.ReferenceType;

import java.util.Map;
import java.util.WeakHashMap;

/**
 * Smarter {@link jodd.introspector.Introspector} caches class data
 * together with class loader information. Therefore, if classes are reloaded dynamically,
 * this introspector will maintains its cache.
 */
public class WeakIntrospector implements Introspector {

	protected Map> cache = new WeakHashMap>();

	/**
	 * Returns class descriptor map.
	 */
	protected Map getClassDescriptorMap(Class type) {
		ClassLoader loader = type.getClassLoader();
		if (loader == null) {
			loader = Thread.currentThread().getContextClassLoader();
		}
		Map map = cache.get(loader);
		if (map == null) {
			map = new ReferenceMap(ReferenceType.WEAK, ReferenceType.WEAK);
			cache.put(loader, map);
		}
		return map;
	}

	/**
	 * {@inheritDoc}
	 */
	public ClassDescriptor lookup(Class type) {
		Map map = getClassDescriptorMap(type);
		ClassDescriptor cd = map.get(type.getName());
		if (cd == null) {
			cd = describeClass(type);
			cd.increaseUsageCount();
			map.put(type.getName(), cd);
		}
		return cd;
	}

	/**
	 * {@inheritDoc}
	 */
	public ClassDescriptor register(Class type) {
		Map map = getClassDescriptorMap(type);
		ClassDescriptor cd = describeClass(type);
		map.put(type.getName(), cd);
		return cd;
	}

	/**
	 * Describes a class by creating a new instance of {@link ClassDescriptor}.
	 */
	protected ClassDescriptor describeClass(Class type) {
		return new ClassDescriptor(type, true, true, true, null);
	}

	/**
	 * {@inheritDoc}
	 */
	public void reset() {
		cache.clear();
	}

}