Commons JXPath example source code file (DynamicPropertyPointer.java)

This example Commons JXPath source code file (DynamicPropertyPointer.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 - Commons JXPath tags/keywords

dynamicpropertyhandler, dynamicpropertypointer, index, jxpathabstractfactoryexception, map, map, nodepointer, object, object, string, string, stringbuffer, util, whole_collection, whole_collection

The Commons JXPath DynamicPropertyPointer.java source code

/*
 * 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.dynamic;

import java.util.Arrays;
import java.util.Map;

import org.apache.commons.jxpath.AbstractFactory;
import org.apache.commons.jxpath.DynamicPropertyHandler;
import org.apache.commons.jxpath.JXPathAbstractFactoryException;
import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.JXPathInvalidAccessException;
import org.apache.commons.jxpath.ri.model.NodePointer;
import org.apache.commons.jxpath.ri.model.beans.PropertyPointer;
import org.apache.commons.jxpath.util.ValueUtils;

/**
 * Pointer pointing to a property of an object with dynamic properties.
 *
 * @author Dmitri Plotnikov
 * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
 */
public class DynamicPropertyPointer extends PropertyPointer {

    private static final long serialVersionUID = -5720585681149150822L;

    private DynamicPropertyHandler handler;
    private String name;
    private String[] names;
    private String requiredPropertyName;

    /**
     * Create a new DynamicPropertyPointer.
     * @param parent pointer
     * @param handler DynamicPropertyHandler
     */
    public DynamicPropertyPointer(NodePointer parent,
            DynamicPropertyHandler handler) {
        super(parent);
        this.handler = handler;
    }

    /**
     * This type of node is auxiliary.
     * @return true
     */
    public boolean isContainer() {
        return true;
    }

    /**
     * Number of the DP object's properties.
     * @return int
     */
    public int getPropertyCount() {
        return getPropertyNames().length;
    }

    /**
     * Names of all properties, sorted alphabetically.
     * @return String[]
     */
    public String[] getPropertyNames() {
        if (names == null) {
            String[] allNames = handler.getPropertyNames(getBean());
            names = new String[allNames.length];
            for (int i = 0; i < names.length; i++) {
                names[i] = allNames[i];
            }
            Arrays.sort(names);
            if (requiredPropertyName != null) {
                int inx = Arrays.binarySearch(names, requiredPropertyName);
                if (inx < 0) {
                    allNames = names;
                    names = new String[allNames.length + 1];
                    names[0] = requiredPropertyName;
                    System.arraycopy(allNames, 0, names, 1, allNames.length);
                    Arrays.sort(names);
                }
            }
        }
        return names;
    }

    /**
     * Returns the name of the currently selected property or "*"
     * if none has been selected.
     * @return String
     */
    public String getPropertyName() {
        if (name == null) {
            String[] names = getPropertyNames();
            name = propertyIndex >= 0 && propertyIndex < names.length ? names[propertyIndex] : "*";
        }
        return name;
    }

    /**
     * Select a property by name.  If the supplied name is
     * not one of the object's existing properties, it implicitly
     * adds this name to the object's property name list. It does not
     * set the property value though. In order to set the property
     * value, call setValue().
     * @param propertyName to set
     */
    public void setPropertyName(String propertyName) {
        setPropertyIndex(UNSPECIFIED_PROPERTY);
        this.name = propertyName;
        requiredPropertyName = propertyName;
        if (names != null && Arrays.binarySearch(names, propertyName) < 0) {
            names = null;
        }
    }

    /**
     * Index of the currently selected property in the list of all
     * properties sorted alphabetically.
     * @return int
     */
    public int getPropertyIndex() {
        if (propertyIndex == UNSPECIFIED_PROPERTY) {
            String[] names = getPropertyNames();
            for (int i = 0; i < names.length; i++) {
                if (names[i].equals(name)) {
                    setPropertyIndex(i);
                    break;
                }
            }
        }
        return super.getPropertyIndex();
    }

    /**
     * Index a property by its index in the list of all
     * properties sorted alphabetically.
     * @param index to set
     */
    public void setPropertyIndex(int index) {
        if (propertyIndex != index) {
            super.setPropertyIndex(index);
            name = null;
        }
    }

    /**
     * Returns the value of the property, not an element of the collection
     * represented by the property, if any.
     * @return Object
     */
    public Object getBaseValue() {
        return handler.getProperty(getBean(), getPropertyName());
    }

    /**
     * If index == WHOLE_COLLECTION, the value of the property, otherwise
     * the value of the index'th element of the collection represented by the
     * property. If the property is not a collection, index should be zero
     * and the value will be the property itself.
     * @return Object
     */
    public Object getImmediateNode() {
        Object value;
        if (index == WHOLE_COLLECTION) {
            value = ValueUtils.getValue(handler.getProperty(
                    getBean(),
                    getPropertyName()));
        }
        else {
            value = ValueUtils.getValue(handler.getProperty(
                    getBean(),
                    getPropertyName()), index);
        }
        return value;
    }

    /**
     * A dynamic property is always considered actual - all keys are apparently
     * existing with possibly the value of null.
     * @return boolean
     */
    protected boolean isActualProperty() {
        return true;
    }

    /**
     * If index == WHOLE_COLLECTION, change the value of the property, otherwise
     * change the value of the index'th element of the collection
     * represented by the property.
     * @param value to set
     */
    public void setValue(Object value) {
        if (index == WHOLE_COLLECTION) {
            handler.setProperty(getBean(), getPropertyName(), value);
        }
        else {
            ValueUtils.setValue(
                handler.getProperty(getBean(), getPropertyName()),
                index,
                value);
        }
    }

    public NodePointer createPath(JXPathContext context) {
        // Ignore the name passed to us, use our own data
        Object collection = getBaseValue();
        if (collection == null) {
            AbstractFactory factory = getAbstractFactory(context);
            boolean success =
                factory.createObject(
                    context,
                    this,
                    getBean(),
                    getPropertyName(),
                    0);
            if (!success) {
                throw new JXPathAbstractFactoryException(
                    "Factory could not create an object for path: " + asPath());
            }
            collection = getBaseValue();
        }

        if (index != WHOLE_COLLECTION) {
            if (index < 0) {
                throw new JXPathInvalidAccessException("Index is less than 1: "
                        + asPath());
            }

            if (index >= getLength()) {
                collection = ValueUtils.expandCollection(collection, index + 1);
                handler.setProperty(getBean(), getPropertyName(), collection);
            }
        }

        return this;
    }

    public NodePointer createPath(JXPathContext context, Object value) {
        if (index == WHOLE_COLLECTION) {
            handler.setProperty(getBean(), getPropertyName(), value);
        }
        else {
            createPath(context);
            ValueUtils.setValue(getBaseValue(), index, value);
        }
        return this;
    }

    public void remove() {
        if (index == WHOLE_COLLECTION) {
            removeKey();
        }
        else if (isCollection()) {
            Object collection = ValueUtils.remove(getBaseValue(), index);
            handler.setProperty(getBean(), getPropertyName(), collection);
        }
        else if (index == 0) {
            removeKey();
        }
    }

    /**
     * Remove the current property.
     */
    private void removeKey() {
        Object bean = getBean();
        if (bean instanceof Map) {
            ((Map) bean).remove(getPropertyName());
        }
        else {
            handler.setProperty(bean, getPropertyName(), null);
        }
    }

    public String asPath() {
        StringBuffer buffer = new StringBuffer();
        buffer.append(getImmediateParentPointer().asPath());
        if (buffer.length() == 0) {
            buffer.append("/.");
        }
        else if (buffer.charAt(buffer.length() - 1) == '/') {
            buffer.append('.');
        }
        buffer.append("[@name='");
        buffer.append(escape(getPropertyName()));
        buffer.append("']");
        if (index != WHOLE_COLLECTION && isCollection()) {
            buffer.append('[').append(index + 1).append(']');
        }
        return buffer.toString();
    }

}