001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 * 
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 * 
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.mina.integration.ognl;
018
019import java.beans.PropertyEditor;
020import java.lang.reflect.Member;
021import java.util.Map;
022
023import ognl.OgnlContext;
024import ognl.TypeConverter;
025
026import org.apache.mina.integration.beans.PropertyEditorFactory;
027
028/**
029 * {@link PropertyEditor}-based implementation of OGNL {@link TypeConverter}.
030 * This converter uses the {@link PropertyEditor} implementations in
031 * <tt>mina-integration-beans</tt> module to perform conversion.  To use this
032 * converter:
033 * <pre><code>
034 * OgnlContext ctx = Ognl.createDefaultContext(root);
035 * ctx.put(OgnlContext.TYPE_CONVERTER_CONTEXT_KEY, new PropertyTypeConverter());
036 * </code></pre>
037 * You can also override {@link #getPropertyEditor(Class, String, Class)}
038 * method to have more control over how an appropriate {@link PropertyEditor}
039 * is chosen.
040 * 
041 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
042 */
043public class PropertyTypeConverter implements TypeConverter {
044
045    @SuppressWarnings("unchecked")
046    public Object convertValue(Map ctx, Object target, Member member, String attrName, Object value, Class toType) {
047        if (value == null) {
048            return null;
049        }
050
051        if (attrName == null) {
052            // I don't know why but OGNL gives null attrName almost always.
053            // Fortunately, we can get the actual attrName with a tiny hack.
054            OgnlContext ognlCtx = (OgnlContext) ctx;
055            attrName = ognlCtx.getCurrentNode().toString().replaceAll("[\" \']+", "");
056        }
057
058        if (toType.isAssignableFrom(value.getClass())) {
059            return value;
060        }
061
062        PropertyEditor e1 = getPropertyEditor(target.getClass(), attrName, value.getClass());
063        if (e1 == null) {
064            throw new IllegalArgumentException("Can't convert " + value.getClass().getSimpleName() + " to "
065                    + String.class.getSimpleName());
066        }
067        e1.setValue(value);
068
069        PropertyEditor e2 = getPropertyEditor(target.getClass(), attrName, toType);
070        if (e2 == null) {
071            throw new IllegalArgumentException("Can't convert " + String.class.getSimpleName() + " to "
072                    + toType.getSimpleName());
073        }
074
075        e2.setAsText(e1.getAsText());
076        return e2.getValue();
077    }
078
079    protected PropertyEditor getPropertyEditor(Class<?> type, String attrName, Class<?> attrType) {
080        return PropertyEditorFactory.getInstance(attrType);
081    }
082}