carbean.java

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/*
 * Copyright 2004-2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


package carstore;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.faces.application.Application;
import javax.faces.application.FacesMessage;
import javax.faces.component.UIComponent;
import javax.faces.component.UIInput;
import javax.faces.component.UISelectItems;
import javax.faces.component.ValueHolder;
import javax.faces.context.FacesContext;
import javax.faces.convert.Converter;
import javax.faces.model.SelectItem;

import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.StringTokenizer;

/**
 * <p>This bean encapsulates a car model, including pricing and package
 * choices.  The system allows the user to customize the properties of
 * this bean with the help of the {@link CarCustomizer}.</p>
 *
 * <h3>Data Access</h3>
 *
 * <p>This is the only bean in the system that has complicated access to
 * the persistent store of data.  In the present implementation, this
 * persistent store is in <code>ResourceBundle</code> instances.</p>
 *
 * <p>There are three data source <code>ResourceBundle</code> files
 * used:</p>
 *
 * 	<ol>
 *
 * 	  <li><p><code>&lt;ModelName&gt;</code></p>
 *
 *        <p>This contains the localized content for this model.  There
 *        is a variant of this file for each supported locale, for
 *        example, <code>Jalopy_de.properties</code></p>
 *
 *         </li>
 *
 * 	  <li><p><code>&lt;Common_properties&gt;</code></p>
 *
 *        <p>This contains the localized content common to all
 *        models.</p>
 *
 *         </li>
 *
 * 	  <li><p><code>&lt;ModelName_options&gt;</code></p>
 *
 *        <p>This contains the non-localized content for this model,
 *        including the non-localized options.  There is only one
 *        variant of this file for all locales for example,
 *        <code>Jalopy_options.properties</code></p>
 *
 *         </li>
 *
 *	</ol>
 *
 * <p>All files conform to the following convention:</p>
 *
 * <code><pre>
 * key
 * key_componentType
 * key_valueType
 * </pre></code>
 *
 * <p>Where <code>key</code> is the name of an attribute of this car.
 * For example, <code>basePrice</code>, or <code>description</code>.
 * <code>key_componentType</code> is the component type of the
 * <code>UIComponent</code> subclass to be used to represent this
 * attribute in the page, for example <code>SelectManyMenu</code>.
 * <code>key_valueType</code> is the data type of the value of the
 * <code>UIComponent</code>, for example <code>java.lang.Integer</code>.
 * For all non-String valueTypes.</p>
 *
 * <p>When the bean is instantiated, we load both of the above
 * properties files and iterate over the keys in each one.  For each
 * key, we look at the <code>componentType</code> and ask the
 * <code>Application</code> to create a component of that type.  We
 * store that <code>UIComponent</code> instance in our
 * <code>components</code> <code>Map</code> under the name
 * <code>key</code>.  We look at the <code>valueType</code> for the
 * <code>key</code>.  For non <code>java.lang.String</code> types, we
 * ask the <code>Application</code> for a <code>Converter</code>
 * instance for that class.  If found, we use it to convert the value
 * for the <code>key</code> to the appropriate type and store that as
 * the <code>value</code> of the <code>UIComponent</code> instance.</p>
 */

public class CarBean extends Object {

    protected static final Log log = LogFactory.getLog(CarBean.class);

    /**
     * <p>The message identifier of the Message to be created if
     * the conversion fails.  The message format string for this
     * message may optionally include a <code>{0}</code>
     * placeholder, which will be replaced by the object and value.</p>
     */
    public static final String CONVERTER_ERROR_MESSAGE_ID =
        "carstore.Converter_Error";


    //
    // Relationship Instance Variables
    //
    
    /**
     * Localized labels
     */

    private ResourceBundle resources = null;

    /**
     * Price data
     */
    private ResourceBundle priceData = null;

    /**
     * Keys: String attribute name, such as engine. Values: UIComponent
     * for the attribute
     */

    private Map components = null;

    /**
     * Keys: String attribute name, such as engine. Values: String value
     * of the component named by key in our components Map.
     */

    private Map attributes = null;
    
    // 
    // Constructors
    //

    public CarBean() {
        this.init(CarStore.DEFAULT_MODEL_PROPERTIES);
    }


    public CarBean(String bundleName) {
        this.init(bundleName);
    }


    /**
     * <p>Initialize our components <code>Map</code> as described in the
     * class documentation.</p>
     *
     * <p>Create a wrapper <code>Map</code> around the components
     * <code>Map</code> that exposes the String converted value of each
     * component.</p>
     */

    private void init(String bundleName) {
        FacesContext context = FacesContext.getCurrentInstance();
        ResourceBundle data = null;
        Enumeration keys = null;
        components = new HashMap();

        // load the labels
        resources =
            ResourceBundle.getBundle(CarStore.CARSTORE_PREFIX +
                                     ".bundles.Resources",
                                     context.getViewRoot().getLocale());

        // load the prices
        priceData = ResourceBundle.getBundle(CarStore.CARSTORE_PREFIX +
                                             ".bundles.OptionPrices");

        // populate the locale-specific information
        if (log.isDebugEnabled()) {
            log.debug("Loading bundle: " + bundleName + ".");
        }
        data = ResourceBundle.getBundle(bundleName,
                                        context.getViewRoot().getLocale());
        if (log.isDebugEnabled()) {
            log.debug("Bundle " + bundleName +
                      " loaded. Reading properties...");
        }
        initComponentsFromProperties(context, data);
        if (log.isDebugEnabled()) {
            log.debug("done.");
        }

        // populate the non-locale-specific information common to all cars
        if (log.isDebugEnabled()) {
            log.debug("Loading bundle: Common_options.");
        }
        data = ResourceBundle.getBundle(CarStore.CARSTORE_PREFIX +
                                        ".bundles.Common_options");
        if (log.isDebugEnabled()) {
            log.debug("Bundle Common_options loaded. Reading properties...");
        }
        initComponentsFromProperties(context, data);
        if (log.isDebugEnabled()) {
            log.debug("done.");
        }

        // populate the non-locale-specific information specific to each car
        if (log.isDebugEnabled()) {
            log.debug("Loading bundle: " + bundleName + "_options.");
        }
        data = ResourceBundle.getBundle(bundleName + "_options");
        if (log.isDebugEnabled()) {
            log.debug("Bundle " + bundleName +
                      "_options loaded. Reading properties...");
        }
        initComponentsFromProperties(context, data);
        if (log.isDebugEnabled()) {
            log.debug("done.");
        }

        // create a read-only Map exposing the values of all of our
        // components.
        attributes =
            new Map() {
                public void clear() {
                    CarBean.this.components.clear();
                }


                public boolean containsKey(Object key) {
                    return CarBean.this.components.containsKey(key);
                }


                public boolean containsValue(Object value) {
                    throw new UnsupportedOperationException();
                }


                public java.util.Set entrySet() {
                    throw new UnsupportedOperationException();
                }


                public boolean equals(Object o) {
                    throw new UnsupportedOperationException();
                }


                public Object get(Object key) {
                    UIComponent component = null;
                    Converter converter = null;
                    Object result = null;
                    if (null == key) {
                        return null;
                    }
                    if (null != (component = (UIComponent)
                        CarBean.this.components.get(key))) {
                        // if this component can have a Converter
                        if (component instanceof ValueHolder) {
                            // try to get it
                            converter = ((ValueHolder) component).
                                getConverter();
                            result = ((ValueHolder) component).getValue();
                        }

                        // if we do have a value
                        if (null != result) {
                            // and we do have a converter
                            if (null != converter) {
                                // convert the value to String