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.util.Map;
020
021import ognl.ObjectPropertyAccessor;
022import ognl.OgnlContext;
023import ognl.OgnlException;
024import ognl.OgnlRuntime;
025import ognl.PropertyAccessor;
026
027/**
028 * An abstract OGNL {@link PropertyAccessor} for MINA constructs.
029 * 
030 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
031 */
032@SuppressWarnings("unchecked")
033public abstract class AbstractPropertyAccessor extends ObjectPropertyAccessor {
034
035    static final Object READ_ONLY_MODE = new Object();
036
037    static final Object QUERY = new Object();
038
039    @Override
040    public final boolean hasGetProperty(OgnlContext context, Object target, Object oname) throws OgnlException {
041        if (oname == null) {
042            return false;
043        }
044
045        if (hasGetProperty0(context, target, oname.toString())) {
046            return true;
047        } else {
048            return super.hasGetProperty(context, target, oname);
049        }
050    }
051
052    @Override
053    public final boolean hasSetProperty(OgnlContext context, Object target, Object oname) throws OgnlException {
054        if (context.containsKey(READ_ONLY_MODE)) {
055            // Return true to trigger setPossibleProperty to throw an exception.
056            return true;
057        }
058
059        if (oname == null) {
060            return false;
061        }
062
063        if (hasSetProperty0(context, target, oname.toString())) {
064            return true;
065        } else {
066            return super.hasSetProperty(context, target, oname);
067        }
068    }
069
070    @Override
071    public final Object getPossibleProperty(Map context, Object target, String name) throws OgnlException {
072        Object answer = getProperty0((OgnlContext) context, target, name);
073        if (answer == OgnlRuntime.NotFound) {
074            answer = super.getPossibleProperty(context, target, name);
075        }
076        return answer;
077    }
078
079    @Override
080    public final Object setPossibleProperty(Map context, Object target, String name, Object value) throws OgnlException {
081        if (context.containsKey(READ_ONLY_MODE)) {
082            throw new OgnlException("Expression must be read-only: " + context.get(QUERY));
083        }
084
085        Object answer = setProperty0((OgnlContext) context, target, name, value);
086        if (answer == OgnlRuntime.NotFound) {
087            answer = super.setPossibleProperty(context, target, name, value);
088        }
089        return answer;
090    }
091
092    protected abstract boolean hasGetProperty0(OgnlContext context, Object target, String name) throws OgnlException;
093
094    protected abstract boolean hasSetProperty0(OgnlContext context, Object target, String name) throws OgnlException;
095
096    protected abstract Object getProperty0(OgnlContext context, Object target, String name) throws OgnlException;
097
098    protected abstract Object setProperty0(OgnlContext context, Object target, String name, Object value)
099            throws OgnlException;
100
101    // The following methods uses the four method above, so there's no need
102    // to override them.
103
104    @Override
105    public final Object getProperty(Map context, Object target, Object oname) throws OgnlException {
106        return super.getProperty(context, target, oname);
107    }
108
109    @Override
110    public final boolean hasGetProperty(Map context, Object target, Object oname) throws OgnlException {
111        return super.hasGetProperty(context, target, oname);
112    }
113
114    @Override
115    public final boolean hasSetProperty(Map context, Object target, Object oname) throws OgnlException {
116        return super.hasSetProperty(context, target, oname);
117    }
118
119    @Override
120    public final void setProperty(Map context, Object target, Object oname, Object value) throws OgnlException {
121        super.setProperty(context, target, oname, value);
122    }
123}