Struts example source code file (XWorkListPropertyAccessor.java)

This example Struts source code file (XWorkListPropertyAccessor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

class, class, collection, exception, inject, inject, list, number, object, object, ognlexception, string, string, util, xworkcollectionpropertyaccessor

The Struts XWorkListPropertyAccessor.java source code

/*
 * Copyright 2002-2006,2009 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.opensymphony.xwork2.ognl.accessor;

import com.opensymphony.xwork2.ObjectFactory;
import com.opensymphony.xwork2.XWorkException;
import com.opensymphony.xwork2.conversion.ObjectTypeDeterminer;
import com.opensymphony.xwork2.conversion.impl.XWorkConverter;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.ognl.OgnlUtil;
import com.opensymphony.xwork2.util.reflection.ReflectionContextState;
import ognl.ListPropertyAccessor;
import ognl.OgnlException;
import ognl.PropertyAccessor;

import java.util.Collection;
import java.util.List;
import java.util.Map;

/**
 * Overrides the list property accessor so in the case of trying
 * to add properties of a given bean and the JavaBean is not present,
 * this class will create the necessary blank JavaBeans.
 *
 * @author Gabriel Zimmerman
 */
public class XWorkListPropertyAccessor extends ListPropertyAccessor {

    private XWorkCollectionPropertyAccessor _sAcc = new XWorkCollectionPropertyAccessor();
    
    private XWorkConverter xworkConverter;
    private ObjectFactory objectFactory;
    private ObjectTypeDeterminer objectTypeDeterminer;
    private OgnlUtil ognlUtil;
    
    @Inject("java.util.Collection")
    public void setXWorkCollectionPropertyAccessor(PropertyAccessor acc) {
        this._sAcc = (XWorkCollectionPropertyAccessor) acc;
    }
    
    @Inject
    public void setXWorkConverter(XWorkConverter conv) {
        this.xworkConverter = conv;
    }
    
    @Inject
    public void setObjectFactory(ObjectFactory fac) {
        this.objectFactory = fac;
    }
    
    @Inject
    public void setObjectTypeDeterminer(ObjectTypeDeterminer ot) {
        this.objectTypeDeterminer = ot;
    }
    
    @Inject
    public void setOgnlUtil(OgnlUtil util) {
        this.ognlUtil = util;
    }

    @Override
    public Object getProperty(Map context, Object target, Object name)
            throws OgnlException {

        if (ReflectionContextState.isGettingByKeyProperty(context)
                || name.equals(XWorkCollectionPropertyAccessor.KEY_PROPERTY_FOR_CREATION)) {
            return _sAcc.getProperty(context, target, name);
        }	else if (name instanceof String) {
            return super.getProperty(context, target, name);
        }
        ReflectionContextState.updateCurrentPropertyPath(context, name);
        //System.out.println("Entering XWorkListPropertyAccessor. Name: " + name);
        Class lastClass = (Class) context.get(XWorkConverter.LAST_BEAN_CLASS_ACCESSED);
        String lastProperty = (String) context.get(XWorkConverter.LAST_BEAN_PROPERTY_ACCESSED);
        
        if (name instanceof Number
                && ReflectionContextState.isCreatingNullObjects(context)
                && objectTypeDeterminer.shouldCreateIfNew(lastClass,lastProperty,target,null,true)) {

            //System.out.println("Getting index from List");
            List list = (List) target;
            int index = ((Number) name).intValue();
            int listSize = list.size();

            if (lastClass == null || lastProperty == null) {
                return super.getProperty(context, target, name);
            }
            Class beanClass = objectTypeDeterminer.getElementClass(lastClass, lastProperty, name);
            if (listSize <= index) {
                Object result = null;

                for (int i = listSize; i < index; i++) {

                    list.add(null);

                }
                try {
                    list.add(index, result = objectFactory.buildBean(beanClass, context));
                } catch (Exception exc) {
                    throw new XWorkException(exc);
                }
                return result;
            } else if (list.get(index) == null) {
                Object result = null;
                try {
                    list.set(index, result = objectFactory.buildBean(beanClass, context));
                } catch (Exception exc) {
                    throw new XWorkException(exc);
                }
                return result;
            }
        }
        return super.getProperty(context, target, name);
    }

    @Override
    public void setProperty(Map context, Object target, Object name, Object value)
            throws OgnlException {

        Class lastClass = (Class) context.get(XWorkConverter.LAST_BEAN_CLASS_ACCESSED);
        String lastProperty = (String) context.get(XWorkConverter.LAST_BEAN_PROPERTY_ACCESSED);
        Class convertToClass = objectTypeDeterminer.getElementClass(lastClass, lastProperty, name);

        if (name instanceof String && value.getClass().isArray()) {
            // looks like the input game in the form of "someList.foo" and
            // we are expected to define the index values ourselves.
            // So let's do it:

            Collection c = (Collection) target;
            Object[] values = (Object[]) value;
            for (Object v : values) {
                try {
                    Object o = objectFactory.buildBean(convertToClass, context);
                    ognlUtil.setValue((String) name, context, o, v);
                    c.add(o);
                } catch (Exception e) {
                    throw new OgnlException("Error converting given String values for Collection.", e);
                }
            }

            // we don't want to do the normal list property setting now, since we've already done the work
            // just return instead
            return;
        }

        Object realValue = getRealValue(context, value, convertToClass);

        if (target instanceof List && name instanceof Number) {
            //make sure there are enough spaces in the List to set
            List list = (List) target;
            int listSize = list.size();
            int count = ((Number) name).intValue();
            if (count >= listSize) {
                for (int i = listSize; i <= count; i++) {
                    list.add(null);
                }
            }
        }

        super.setProperty(context, target, name, realValue);
    }

    private Object getRealValue(Map context, Object value, Class convertToClass) {
        if (value == null || convertToClass == null) {
            return value;
        }
        return xworkConverter.convertValue(context, value, convertToClass);
    }
}