| /* |
| * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.tools.internal.xjc.reader; |
| |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.InvocationTargetException; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| import com.sun.tools.internal.xjc.ErrorReceiver; |
| import com.sun.tools.internal.xjc.model.Model; |
| |
| /** |
| * Holds all the binding related singleton components in a "ring", |
| * and let you access those components, creating them as necessary. |
| * |
| * <p> |
| * A {@link Ring} is local to a thread, |
| * and only one instanceof {@link Ring} can be active at any given time. |
| * |
| * Use {@link #begin()} and {@link #end(Ring)} to start/end a ring scope. |
| * Inside a scope, use {@link #get()} to obtain the instance. |
| * |
| * <p> |
| * When a {@link Model} is built by the reader, an active {@link Ring} scope |
| * is assumed. |
| * |
| * |
| * <h2>Components in Ring</h2> |
| * <p> |
| * Depending on the schema language we are dealing with, different |
| * components are in the model. But at least the following components |
| * are in the ring. |
| * |
| * <ul> |
| * <li>{@link ErrorReceiver} |
| * </ul> |
| * |
| * @author Kohsuke Kawaguchi |
| */ |
| public final class Ring { |
| |
| private final Map<Class,Object> components = new HashMap<Class,Object>(); |
| |
| private static final ThreadLocal<Ring> instances = new ThreadLocal<Ring>(); |
| |
| private Ring() {} |
| |
| public static <T> void add( Class<T> clazz, T instance ) { |
| assert !get().components.containsKey(clazz); |
| get().components.put(clazz,instance); |
| } |
| |
| public static <T> void add( T o ) { |
| add((Class<T>)o.getClass(),o); |
| } |
| |
| public static <T> T get( Class<T> key ) { |
| T t = (T)get().components.get(key); |
| if(t==null) { |
| try { |
| Constructor<T> c = key.getDeclaredConstructor(); |
| c.setAccessible(true); |
| t = c.newInstance(); |
| if(!get().components.containsKey(key)) |
| // many components register themselves. |
| add(key,t); |
| } catch (InstantiationException e) { |
| throw new Error(e); |
| } catch (IllegalAccessException e) { |
| throw new Error(e); |
| } catch (NoSuchMethodException e) { |
| throw new Error(e); |
| } catch (InvocationTargetException e) { |
| throw new Error(e); |
| } |
| } |
| |
| assert t!=null; |
| return t; |
| } |
| |
| /** |
| * A {@link Ring} instance is associated with a thread. |
| */ |
| public static Ring get() { |
| return instances.get(); |
| } |
| |
| /** |
| * Starts a new scope. |
| */ |
| public static Ring begin() { |
| Ring r = null; |
| synchronized (instances) { |
| r = instances.get(); |
| instances.set(new Ring()); |
| } |
| return r; |
| } |
| |
| /** |
| * Ends a scope. |
| */ |
| public static void end(Ring old) { |
| synchronized (instances) { |
| instances.remove(); |
| instances.set(old); |
| } |
| } |
| } |