objectpropertyaccessor.java

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//--------------------------------------------------------------------------
//	Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
//  All rights reserved.
//
//	Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are
//  met:
//
//	Redistributions of source code must retain the above copyright notice,
//  this list of conditions and the following disclaimer.
//	Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//	Neither the name of the Drew Davidson nor the names of its contributors
//  may be used to endorse or promote products derived from this software
//  without specific prior written permission.
//
//	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
//  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
//  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
//  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
//  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
//  DAMAGE.
//--------------------------------------------------------------------------
package ognl;

import java.beans.IntrospectionException;
import java.util.Map;

/**
 * Implementation of PropertyAccessor that uses reflection on the target object's class to
 * find a field or a pair of set/get methods with the given property name.
 * @author Luke Blanshard ([e-mail])
 * @author Drew Davidson ([e-mail])
 */
public class ObjectPropertyAccessor implements PropertyAccessor
{
    /**
        Returns OgnlRuntime.NotFound if the property does not exist.
     */
    public Object getPossibleProperty( Map context, Object target, String name) throws OgnlException
    {
        Object          result;
        OgnlContext     ognlContext = (OgnlContext)context;

        try {
            if ((result = OgnlRuntime.getMethodValue(ognlContext, target, name, true)) == OgnlRuntime.NotFound) {
                result = OgnlRuntime.getFieldValue(ognlContext, target, name, true);
            }
        } catch (IntrospectionException ex) {
            throw new OgnlException(name, ex);
        } catch (OgnlException ex) {
            throw ex;
        } catch (Exception ex) {
            throw new OgnlException(name, ex);
        }
        return result;
    }

    /**
        Returns OgnlRuntime.NotFound if the property does not exist.
     */
    public Object setPossibleProperty( Map context, Object target, String name, Object value) throws OgnlException
    {
        Object          result = null;
        OgnlContext     ognlContext = (OgnlContext)context;

        try {
            if (!OgnlRuntime.setMethodValue(ognlContext, target, name, value, true)) {
                result = OgnlRuntime.setFieldValue(ognlContext, target, name, value) ? null : OgnlRuntime.NotFound;
            }
        } catch (IntrospectionException ex) {
            throw new OgnlException(name, ex);
        } catch (OgnlException ex) {
            throw ex;
        } catch (Exception ex) {
            throw new OgnlException(name, ex);
        }
        return result;
    }

    public boolean hasGetProperty( OgnlContext context, Object target, Object oname ) throws OgnlException
    {
        try {
            return OgnlRuntime.hasGetProperty( context, target, oname );
        } catch (IntrospectionException ex) {
            throw new OgnlException("checking if " + target + " has gettable property " + oname, ex);
        }
    }

    public boolean hasGetProperty( Map context, Object target, Object oname ) throws OgnlException
    {
        return hasGetProperty((OgnlContext)context, target, oname);
    }

    public boolean hasSetProperty( OgnlContext context, Object target, Object oname ) throws OgnlException
    {
        try {
            return OgnlRuntime.hasSetProperty( context, target, oname );
        } catch (IntrospectionException ex) {
            throw new OgnlException("checking if " + target + " has settable property " + oname, ex);
        }
    }

    public boolean hasSetProperty( Map context, Object target, Object oname ) throws OgnlException
    {
        return hasSetProperty((OgnlContext)context, target, oname);
    }

    public Object getProperty( Map context, Object target, Object oname ) throws OgnlException
    {
        Object              result = null;
        String              name = oname.toString();

        if ((result = getPossibleProperty(context, target, name)) == OgnlRuntime.NotFound) {
            throw new NoSuchPropertyException(target, name);
        }
        return result;
    }

    public void setProperty( Map context, Object target, Object oname, Object value ) throws OgnlException
    {
        String          name = oname.toString();

        if (setPossibleProperty(context, target, name, value) == OgnlRuntime.NotFound) {
            throw new NoSuchPropertyException(target, name);
        }
    }
}