001/* 002 * The contents of this file are subject to the terms of the Common Development and 003 * Distribution License (the License). You may not use this file except in compliance with the 004 * License. 005 * 006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the 007 * specific language governing permission and limitations under the License. 008 * 009 * When distributing Covered Software, include this CDDL Header Notice in each file and include 010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL 011 * Header, with the fields enclosed by brackets [] replaced by your own identifying 012 * information: "Portions Copyright [year] [name of copyright owner]". 013 * 014 * Copyright 2010-2011 ApexIdentity Inc. 015 * Portions Copyright 2011-2014 ForgeRock AS. 016 */ 017 018package org.forgerock.openig.heap; 019 020import static java.util.Collections.*; 021 022import java.util.List; 023 024import org.forgerock.http.util.Loader; 025 026/** 027 * Loads {@link Heaplet} classes based on the class of object they create. Three methods of 028 * locating the heaplet class are attempted, in the following order: 029 * <ol> 030 * <li>The {@link Loader} class attempts to locate a {@code HeapletFactory} 031 * interface implementation suitable for the class being created.</li> 032 * <li>A nested {@code Heaplet} class is searched for. Example: creating 033 * {@code com.example.Foo} would search for a heaplet class named 034 * {@code com.example.Foo$Heaplet}.</li> 035 * <li>A standalone class with the name {@code Heaplet} appended. Example: creating 036 * {@code com.example.Foo} would search for a heaplet class named 037 * {@code com.example.FooHeaplet}. </li> 038 * </ol> 039 */ 040public final class Heaplets { 041 042 /** List of classpath-discovered {@link HeapletFactory} services. */ 043 private static final List<HeapletFactory> SERVICES = unmodifiableList(Loader.loadList(HeapletFactory.class)); 044 045 /** Static methods only. */ 046 private Heaplets() { 047 } 048 049 /** 050 * Returns the heaplet that creates an instance of the specified class, or {@code null} 051 * if no such heaplet could be found. 052 * 053 * @param c the class that the heaplet is responsible for creating. 054 * @return the heaplet that creates the specified class, or {@code null} if not found. 055 */ 056 public static Heaplet getHeaplet(Class<?> c) { 057 058 Heaplet heaplet; 059 060 // try service loader 061 for (HeapletFactory factory : SERVICES) { 062 heaplet = factory.newInstance(c); 063 if (heaplet != null) { 064 return heaplet; 065 } 066 } 067 068 // try nested class 069 heaplet = Loader.newInstance(c.getName() + "$Heaplet", Heaplet.class); 070 071 if (heaplet == null) { 072 // try standalone class 073 heaplet = Loader.newInstance(c.getName() + "Heaplet", Heaplet.class); 074 } 075 return heaplet; 076 } 077}