Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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 org.apache.commons.jxpath.ri.model.beans; import org.apache.commons.jxpath.AbstractFactory; import org.apache.commons.jxpath.JXPathAbstractFactoryException; import org.apache.commons.jxpath.JXPathContext; import org.apache.commons.jxpath.JXPathIntrospector; import org.apache.commons.jxpath.ri.QName; import org.apache.commons.jxpath.ri.model.NodePointer; import org.apache.commons.jxpath.util.ValueUtils; /** * A pointer allocated by a PropertyOwnerPointer to represent the value of * a property of the parent object. * * @author Dmitri Plotnikov * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $ */ public abstract class PropertyPointer extends NodePointer { public static final int UNSPECIFIED_PROPERTY = Integer.MIN_VALUE; /** property index */ protected int propertyIndex = UNSPECIFIED_PROPERTY; /** owning object */ protected Object bean; /** * Takes a javabean, a descriptor of a property of that object and * an offset within that property (starting with 0). * @param parent parent pointer */ public PropertyPointer(NodePointer parent) { super(parent); } /** * Get the property index. * @return int index */ public int getPropertyIndex() { return propertyIndex; } /** * Set the property index. * @param index property index */ public void setPropertyIndex(int index) { if (propertyIndex != index) { propertyIndex = index; setIndex(WHOLE_COLLECTION); } } /** * Get the parent bean. * @return Object */ public Object getBean() { if (bean == null) { bean = getImmediateParentPointer().getNode(); } return bean; } public QName getName() { return new QName(null, getPropertyName()); } /** * Get the property name. * @return String property name. */ public abstract String getPropertyName(); /** * Set the property name. * @param propertyName property name to set. */ public abstract void setPropertyName(String propertyName); /** * Count the number of properties represented. * @return int */ public abstract int getPropertyCount(); /** * Get the names of the included properties. * @return String[] */ public abstract String[] getPropertyNames(); /** * Learn whether this pointer references an actual property. * @return true if actual */ protected abstract boolean isActualProperty(); public boolean isActual() { if (!isActualProperty()) { return false; } return super.isActual(); } private static final Object UNINITIALIZED = new Object(); private Object value = UNINITIALIZED; public Object getImmediateNode() { if (value == UNINITIALIZED) { value = index == WHOLE_COLLECTION ? ValueUtils.getValue(getBaseValue()) : ValueUtils.getValue(getBaseValue(), index); } return value; } public boolean isCollection() { Object value = getBaseValue(); return value != null && ValueUtils.isCollection(value); } public boolean isLeaf() { Object value = getNode(); return value == null || JXPathIntrospector.getBeanInfo(value.getClass()).isAtomic(); } /** * If the property contains a collection, then the length of that * collection, otherwise - 1. * @return int length */ public int getLength() { return ValueUtils.getLength(getBaseValue()); } /** * Returns a NodePointer that can be used to access the currently * selected property value. * @return NodePointer */ public NodePointer getImmediateValuePointer() { return NodePointer.newChildNodePointer((NodePointer) this.clone(), getName(), getImmediateNode()); } public NodePointer createPath(JXPathContext context) { if (getImmediateNode() == null) { AbstractFactory factory = getAbstractFactory(context); int inx = (index == WHOLE_COLLECTION ? 0 : index); boolean success = factory.createObject(context, this, getBean(), getPropertyName(), inx); if (!success) { throw new JXPathAbstractFactoryException( "Factory " + factory + " could not create an object for path: " + asPath()); } } return this; } public NodePointer createPath(JXPathContext context, Object value) { // If neccessary, expand collection if (index != WHOLE_COLLECTION && index >= getLength()) { createPath(context); } setValue(value); return this; } public NodePointer createChild(JXPathContext context, QName name, int index, Object value) { PropertyPointer prop = (PropertyPointer) clone(); if (name != null) { prop.setPropertyName(name.toString()); } prop.setIndex(index); return prop.createPath(context, value); } public NodePointer createChild(JXPathContext context, QName name, int index) { PropertyPointer prop = (PropertyPointer) clone(); if (name != null) { prop.setPropertyName(name.toString()); } prop.setIndex(index); return prop.createPath(context); } public int hashCode() { return getImmediateParentPointer().hashCode() + propertyIndex + index; } public boolean equals(Object object) { if (object == this) { return true; } if (!(object instanceof PropertyPointer)) { return false; } PropertyPointer other = (PropertyPointer) object; if (parent != other.parent && (parent == null || !parent.equals(other.parent))) { return false; } if (getPropertyIndex() != other.getPropertyIndex() || !getPropertyName().equals(other.getPropertyName())) { return false; } int iThis = (index == WHOLE_COLLECTION ? 0 : index); int iOther = (other.index == WHOLE_COLLECTION ? 0 : other.index); return iThis == iOther; } public int compareChildNodePointers(NodePointer pointer1, NodePointer pointer2) { return getValuePointer().compareChildNodePointers(pointer1, pointer2); } }