jythonwrapper.java

freemaker安装软件

/*
 * Copyright (c) 2003 The Visigoth Software Society. All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Visigoth Software Society (http://www.visigoths.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the 
 *    project contributors may be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
 *    nor may "FreeMarker" or "Visigoth" appear in their names
 *    without prior written permission of the Visigoth Software Society.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 VISIGOTH SOFTWARE SOCIETY OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Visigoth Software Society. For more
 * information on the Visigoth Software Society, please see
 * http://www.visigoths.org/
 */

package freemarker.ext.jython;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;
import java.util.Map;

import org.python.core.Py;
import org.python.core.PyDictionary;
import org.python.core.PyFloat;
import org.python.core.PyInteger;
import org.python.core.PyJavaInstance;
import org.python.core.PyLong;
import org.python.core.PyNone;
import org.python.core.PyObject;
import org.python.core.PySequence;
import org.python.core.PyString;
import org.python.core.PyStringMap;

import freemarker.ext.beans.BeansWrapper;
import freemarker.ext.beans.DateModel;
import freemarker.ext.util.ModelCache;
import freemarker.ext.util.WrapperTemplateModel;
import freemarker.template.AdapterTemplateModel;
import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateBooleanModel;
import freemarker.template.TemplateHashModel;
import freemarker.template.TemplateHashModelEx;
import freemarker.template.TemplateMethodModel;
import freemarker.template.TemplateMethodModelEx;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelAdapter;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateNumberModel;
import freemarker.template.TemplateScalarModel;
import freemarker.template.TemplateSequenceModel;
import freemarker.template.utility.OptimizerUtil;

/**
 * An object wrapper that wraps Jython objects into FreeMarker template models
 * and vice versa.
 * @version $Id: JythonWrapper.java,v 1.23.2.1 2005/10/04 16:18:08 revusky Exp $
 * @author Attila Szegedi
 */
public class JythonWrapper implements ObjectWrapper
{
    private static final Class PYOBJECT_CLASS = PyObject.class;
    public static final JythonWrapper INSTANCE = new JythonWrapper();

    private final ModelCache modelCache = new ModelCache(this);

    private boolean attributesShadowItems = true;

    public JythonWrapper()
    {
    }
    
    /**
     * Sets whether this wrapper caches model instances. Default is false.
     * When set to true, calling {@link #wrap(Object)} multiple times for
     * the same object will return the same model.
     */
    public void setUseCache(boolean useCache)
    {
        modelCache.setUseCache(useCache);
    }
    
    /**
     * Sets whether attributes shadow items in wrapped objects. When true 
     * (this is the default value), <code>${object.name}</code> will first 
     * try to locate a python attribute with the specified name on the object
     * using {@link PyObject#__findattr__(java.lang.String)}, and only if it 
     * doesn't find the attribute will it call 
     * {@link PyObject#__getitem__(org.python.core.PyObject)}.
     * When set to false, the lookup order is reversed and items
     * are looked up before attributes.
     */
    public synchronized void setAttributesShadowItems(boolean attributesShadowItems)
    {
        this.attributesShadowItems = attributesShadowItems;
    }
    
    boolean isAttributesShadowItems()
    {
        return attributesShadowItems;
    }
    
    /**
     * Wraps the passed Jython object into a FreeMarker template model. If
     * the object is not a Jython object, it is first coerced into one using
     * {@link Py#java2py(java.lang.Object)}. {@link PyDictionary} and {@link
     * PyStringMap} are wrapped into a hash model, {@link PySequence}
     * descendants are wrapped into a sequence model, {@link PyInteger}, {@link
     * PyLong}, and {@link PyFloat} are wrapped into a number model. All objects
     * are wrapped into a scalar model (using {@link Object#toString()} and a
     * boolean model (using {@link PyObject#__nonzero__()}. For internal
     * general-purpose {@link PyObject}s returned from a call to {@link
     * #unwrap(TemplateModel)}, the template model that was passed to
     * <code>unwrap</code> is returned.
     */
    public TemplateModel wrap(Object obj)
    {
        if(obj == null) {
            return null;
        }
        if (obj instanceof TemplateModel) {
            return (TemplateModel)obj;

        }
        if(obj instanceof TemplateModelAdapter) {
            return ((TemplateModelAdapter)obj).getTemplateModel();
        }
        boolean asHash = false;
        boolean asSequence = false;
        if(obj instanceof PyJavaInstance) {
            Object jobj = ((PyJavaInstance)obj).__tojava__(java.lang.Object.class);
            // FreeMarker-aware, Jython-wrapped Java objects are left intact 
            if(jobj instanceof TemplateModel) {
                return (TemplateModel)jobj; 
            }
            if(jobj instanceof Map) {
                asHash = true;
            }
            if (jobj instanceof Date) {
                return new DateModel((Date) jobj, BeansWrapper.getDefaultInstance());
            }
            else if(jobj instanceof Collection) {
                asSequence = true;
                // FIXME: This is an ugly hack, but AFAIK, there's no better
                // solution if we want to have Sets and other non-List
                // collections managed by this layer, as Jython quite clearly
                // doesn't support sets.  
                if(!(jobj instanceof List)) {
                    obj = new ArrayList((Collection)jobj); 
                }
            }
        }
        
        // If it's not a PyObject, first make a PyObject out of it.
        if(!(obj instanceof PyObject))
        {
            obj = Py.java2py(obj);
        }
        if(asHash || obj instanceof PyDictionary || obj instanceof PyStringMap)
        {
            return modelCache.getInstance(obj, JythonHashModel.FACTORY);
        }
        if(asSequence || obj instanceof PySequence)
        {
            return modelCache.getInstance(obj, JythonSequenceModel.FACTORY);
        }
        if(obj instanceof PyInteger || obj instanceof PyLong || obj instanceof PyFloat)