1   /*   Copyright 2004 The Apache Software Foundation
    2   *
    3   *   Licensed under the Apache License, Version 2.0 (the "License");
    4   *   you may not use this file except in compliance with the License.
    5   *   You may obtain a copy of the License at
    6   *
    7   *       http://www.apache.org/licenses/LICENSE-2.0
    8   *
    9   *   Unless required by applicable law or agreed to in writing, software
   10   *   distributed under the License is distributed on an "AS IS" BASIS,
   11   *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   12   *   See the License for the specific language governing permissions and
   13   *  limitations under the License.
   14   */
   15   
   16   package org.apache.xmlbeans.impl.config;
   17   
   18   import org.apache.xmlbeans.XmlObject;
   19   import org.apache.xmlbeans.PrePostExtension;
   20   import org.apache.xmlbeans.impl.jam.JamClassLoader;
   21   import org.apache.xmlbeans.impl.jam.JClass;
   22   import org.apache.xmlbeans.impl.jam.JMethod;
   23   import org.apache.xmlbeans.impl.xb.xmlconfig.Extensionconfig;
   24   
   25   
   26   public class PrePostExtensionImpl implements PrePostExtension
   27   {
   28   
   29       private static JClass[] PARAMTYPES_PREPOST = null; //new JClass[]{int.class, XmlObject.class, QName.class, boolean.class, int.class};
   30       private static final String[] PARAMTYPES_STRING = new String[] {"int", "org.apache.xmlbeans.XmlObject",
   31           "javax.xml.namespace.QName", "boolean", "int"};
   32       private static final String SIGNATURE;
   33       static
   34       {
   35           String sig = "(";
   36           for (int i = 0; i < PARAMTYPES_STRING.length; i++)
   37           {
   38               String t = PARAMTYPES_STRING[i];
   39               if (i!=0)
   40                   sig += ", ";
   41               sig += t;
   42           }
   43           SIGNATURE = sig + ")";
   44       }
   45   
   46       private NameSet _xbeanSet;
   47       private JClass _delegateToClass;
   48       private String _delegateToClassName;
   49       private JMethod _preSet;
   50       private JMethod _postSet;
   51   
   52       static PrePostExtensionImpl newInstance(JamClassLoader jamLoader, NameSet xbeanSet, Extensionconfig.PrePostSet prePostXO)
   53       {
   54           if (prePostXO==null)
   55               return null;
   56   
   57           PrePostExtensionImpl result = new PrePostExtensionImpl();
   58   
   59           result._xbeanSet = xbeanSet;
   60           result._delegateToClassName = prePostXO.getStaticHandler();
   61           result._delegateToClass = InterfaceExtensionImpl.validateClass(jamLoader, result._delegateToClassName, prePostXO);
   62   
   63           if ( result._delegateToClass==null ) // no HandlerClass
   64           {
   65               BindingConfigImpl.warning("Handler class '" + prePostXO.getStaticHandler() + "' not found on classpath, skip validation.", prePostXO);
   66               return result;
   67           }
   68   
   69           if (!result.lookAfterPreAndPost(jamLoader, prePostXO))
   70               return null;
   71   
   72           return result;
   73       }
   74   
   75       private boolean lookAfterPreAndPost(JamClassLoader jamLoader, XmlObject loc)
   76       {
   77           assert _delegateToClass!=null : "Delegate to class handler expected.";
   78           boolean valid = true;
   79   
   80           initParamPrePost(jamLoader);
   81   
   82           _preSet = InterfaceExtensionImpl.getMethod(_delegateToClass, "preSet", PARAMTYPES_PREPOST);
   83           if (_preSet==null)
   84           {} // not available is ok, _preSet will be null
   85   
   86           if (_preSet!=null && !_preSet.getReturnType().equals(jamLoader.loadClass("boolean")))
   87           {
   88               // just emit an warning and don't remember as a preSet
   89               BindingConfigImpl.warning("Method '" + _delegateToClass.getSimpleName() +
   90                   ".preSet" + SIGNATURE + "' " +
   91                   "should return boolean to be considered for a preSet handler.", loc);
   92               _preSet = null;
   93           }
   94   
   95           _postSet = InterfaceExtensionImpl.getMethod(_delegateToClass, "postSet", PARAMTYPES_PREPOST);
   96           if (_postSet==null)
   97           {} // not available is ok, _postSet will be null
   98   
   99           if (_preSet==null && _postSet==null)
  100           {
  101               BindingConfigImpl.error("prePostSet handler specified '" + _delegateToClass.getSimpleName() +
  102                   "' but no preSet" + SIGNATURE + " or " +
  103                   "postSet" + SIGNATURE + " methods found.", loc);
  104               valid = false;
  105           }
  106   
  107           return valid;
  108       }
  109   
  110       private void initParamPrePost(JamClassLoader jamLoader)
  111       {
  112           if (PARAMTYPES_PREPOST==null)
  113           {
  114               PARAMTYPES_PREPOST = new JClass[PARAMTYPES_STRING.length];
  115               for (int i = 0; i < PARAMTYPES_PREPOST.length; i++)
  116               {
  117                   PARAMTYPES_PREPOST[i] = jamLoader.loadClass(PARAMTYPES_STRING[i]);
  118                   if (PARAMTYPES_PREPOST[i]==null)
  119                   {
  120                       throw new IllegalStateException("JAM should have access to the following types " + SIGNATURE);
  121                   }
  122               }
  123           }
  124       }
  125   
  126       // public methods
  127       public NameSet getNameSet()
  128       {
  129           return _xbeanSet;
  130       }
  131   
  132       public boolean contains(String fullJavaName)
  133       {
  134           return _xbeanSet.contains(fullJavaName);
  135       }
  136   
  137       public boolean hasPreCall()
  138       {
  139           return _preSet!=null;
  140       }
  141   
  142       public boolean hasPostCall()
  143       {
  144           return _postSet!=null;
  145       }
  146   
  147       public String getStaticHandler()
  148       {
  149           return _delegateToClassName;
  150       }
  151   
  152       /**
  153        * Returns the name of the handler in a form that can be put in a java source.
  154        */
  155       public String getHandlerNameForJavaSource()
  156       {
  157           // used only in validation
  158           if (_delegateToClass==null)
  159               return null;
  160   
  161           return InterfaceExtensionImpl.emitType(_delegateToClass);
  162       }
  163   
  164       boolean hasNameSetIntersection(PrePostExtensionImpl ext)
  165       {
  166           return !NameSet.EMPTY.equals(_xbeanSet.intersect(ext._xbeanSet));
  167       }
  168   
  169   }