/* gnu.java.beans.decoder.VoidHandler Copyright (C) 2004 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath 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 for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ package gnu.java.beans.decoder; import java.beans.ExceptionListener; import org.xml.sax.Attributes; public class VoidHandler extends AbstractElementHandler { /** * @param PersistenceParser */ VoidHandler(ElementHandler parent) { super(parent, true); } protected Context startElement( Attributes attributes, ExceptionListener exceptionListener) throws AssemblyException { Context ctx = startElementImpl(attributes); ctx.setStatement(true); return ctx; } private Context startElementImpl(Attributes attributes) throws AssemblyException { String id = attributes.getValue("id"); String className = attributes.getValue("class"); String methodName = attributes.getValue("method"); String propertyName = attributes.getValue("property"); String index = attributes.getValue("index"); if (className != null) { try { Class klass = instantiateClass(className); // class name exists which means that we are in a static context. // so we may want to ... // run a constructor if methodName is "new" or null if (methodName == null || methodName.equals("new")) // if the id is null the result cannot be by the decoder accessed but the // constructor may have side effects (e.g. registering itself in a global registry) return new ConstructorContext(id, klass); // (falling through is important!) // run a static method on the given class (if methodName exists, which is implied already) return new StaticMethodContext(id, klass, methodName); } catch (ClassNotFoundException cnfe) { throw new AssemblyException(cnfe); } } else { // className does not exist which means we are in the context of // some object and want to ... // access an element by index if (index != null) { // note: whether this resolves into get(i) or set(i, o) depends on the // number of arguments and is decided by the ObjectAssembler try { return new IndexContext(id, Integer.parseInt(index)); } catch (NumberFormatException nfe) { throw new AssemblyException(nfe); } } // access a method if methodName exists if (methodName != null) return new MethodContext(id, methodName); // (falling through is important!) // access a property if a propertyName exists if (propertyName != null && propertyName.length() > 0) // this is reported as an ordinary method invocation where the propertyName is // converted into a 'setter'-method name: convert first character of property name // to upper case and prepend 'set' // Note: This will be a setter-method because the tag implies that no return // value is expected (but a side effect) return new PropertyContext(id, propertyName); } // if code reaches this point the tag has wrong attributes. The following test // does not make it better but can provide are more specific error message for // a common mistake: tags are not allowed to have an idref attribute throw new AssemblyException( new IllegalArgumentException( (attributes.getValue("idref") == null) ? "Missing attributes for tag" : " does not support 'idref' attribute.")); } }