1 /*
   2  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.xml.internal.bind.v2.runtime;
  27 
  28 import java.util.HashMap;
  29 
  30 import javax.xml.bind.ValidationEvent;
  31 import javax.xml.bind.ValidationEventHandler;
  32 import javax.xml.bind.ValidationEventLocator;
  33 import javax.xml.bind.annotation.adapters.XmlAdapter;
  34 import javax.xml.bind.helpers.ValidationEventImpl;
  35 
  36 import com.sun.xml.internal.bind.v2.ClassFactory;
  37 import com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallingContext;
  38 
  39 import org.xml.sax.ErrorHandler;
  40 import org.xml.sax.SAXException;
  41 import org.xml.sax.SAXParseException;
  42 
  43 /**
  44  * Object that coordinates the marshalling/unmarshalling.
  45  *
  46  * <p>
  47  * This class takes care of the logic that allows code to obtain
  48  * {@link UnmarshallingContext} and {@link XMLSerializer} instances
  49  * during the unmarshalling/marshalling.
  50  *
  51  * <p>
  52  * This is done by using a {@link ThreadLocal}. Therefore one unmarshalling/marshalling
  53  * episode has to be done from the beginning till end by the same thread.
  54  * (Note that the same {@link Coordinator} can be then used by a different thread
  55  * for an entirely different episode.)
  56  *
  57  * This class also maintains the user-configured instances of {@link XmlAdapter}s.
  58  *
  59  * <p>
  60  * This class implements {@link ErrorHandler} and propages erros to this object
  61  * as the {@link ValidationEventHandler}, which will be implemented in a derived class.
  62  *
  63  * @author Kohsuke Kawaguchi
  64  */
  65 public abstract class Coordinator implements ErrorHandler, ValidationEventHandler {
  66 
  67     private final HashMap<Class<? extends XmlAdapter>,XmlAdapter> adapters =
  68             new HashMap<Class<? extends XmlAdapter>,XmlAdapter>();
  69 
  70 
  71     public final XmlAdapter putAdapter(Class<? extends XmlAdapter> c, XmlAdapter a) {
  72         if(a==null)
  73             return adapters.remove(c);
  74         else
  75             return adapters.put(c,a);
  76     }
  77 
  78     /**
  79      * Gets the instance of the adapter.
  80      *
  81      * @return
  82      *      always non-null.
  83      */
  84     public final <T extends XmlAdapter> T getAdapter(Class<T> key) {
  85         T v = key.cast(adapters.get(key));
  86         if(v==null) {
  87             v = ClassFactory.create(key);
  88             putAdapter(key,v);
  89         }
  90         return v;
  91     }
  92 
  93     public <T extends XmlAdapter> boolean containsAdapter(Class<T> type) {
  94         return adapters.containsKey(type);
  95     }
  96 
  97     // this much is necessary to avoid calling get and set twice when we push.
  98     private static final ThreadLocal<Coordinator> activeTable = new ThreadLocal<Coordinator>();
  99 
 100     /**
 101      * The {@link Coordinator} in charge before this {@link Coordinator}.
 102      */
 103     private Coordinator old;
 104 
 105     /**
 106      * Called whenever an execution flow enters the realm of this {@link Coordinator}.
 107      */
 108     protected final void pushCoordinator() {
 109         old = activeTable.get();
 110         activeTable.set(this);
 111     }
 112 
 113     /**
 114      * Called whenever an execution flow exits the realm of this {@link Coordinator}.
 115      */
 116     protected final void popCoordinator() {
 117         if (old != null)
 118             activeTable.set(old);
 119         else
 120             activeTable.remove();
 121         old = null; // avoid memory leak
 122     }
 123 
 124     public static Coordinator _getInstance() {
 125         return activeTable.get();
 126     }
 127 
 128 //
 129 //
 130 // ErrorHandler implementation
 131 //
 132 //
 133     /**
 134      * Gets the current location. Used for reporting the error source location.
 135      */
 136     protected abstract ValidationEventLocator getLocation();
 137 
 138     public final void error(SAXParseException exception) throws SAXException {
 139         propagateEvent( ValidationEvent.ERROR, exception );
 140     }
 141 
 142     public final void warning(SAXParseException exception) throws SAXException {
 143         propagateEvent( ValidationEvent.WARNING, exception );
 144     }
 145 
 146     public final void fatalError(SAXParseException exception) throws SAXException {
 147         propagateEvent( ValidationEvent.FATAL_ERROR, exception );
 148     }
 149 
 150     private void propagateEvent( int severity, SAXParseException saxException )
 151         throws SAXException {
 152 
 153         ValidationEventImpl ve =
 154             new ValidationEventImpl( severity, saxException.getMessage(), getLocation() );
 155 
 156         Exception e = saxException.getException();
 157         if( e != null ) {
 158             ve.setLinkedException( e );
 159         } else {
 160             ve.setLinkedException( saxException );
 161         }
 162 
 163         // call the client's event handler.  If it returns false, then bail-out
 164         // and terminate the unmarshal operation.
 165         boolean result = handleEvent( ve );
 166         if( ! result ) {
 167             // bail-out of the parse with a SAX exception, but convert it into
 168             // an UnmarshalException back in in the AbstractUnmarshaller
 169             throw saxException;
 170         }
 171     }
 172 }