componentfactory.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/util/ComponentFactory.java,v $
// $RCSfile: ComponentFactory.java,v $
// $Revision: 1.9.2.5 $
// $Date: 2005/08/11 21:03:29 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.util;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.Properties;
import java.util.Vector;

import com.bbn.openmap.BasicI18n;
import com.bbn.openmap.PropertyConsumer;
import com.bbn.openmap.event.ProgressEvent;
import com.bbn.openmap.event.ProgressSupport;

/**
 * The OpenMap ComponentFactory is a class that can construct objects
 * from class names, with the added capability of passing the new
 * object a Properties object to initialize itself. The new object may
 * also receive a property prefix to use to scope its properties from
 * the Properties object. It is sensitive to the OpenMap paradigm of
 * marker names in a list: That a list of objects can be defined as a
 * space separated names (marker names) within a String. Those marker
 * names can serve as a prefix for other properties within a
 * Properties object, as well as the prefix for a '.class' property to
 * define the class name for the new object.
 */
public class ComponentFactory {

    /**
     * The property to use for the class name of new objects -
     * ".class". Expects that a prefix will be prepended to it.
     */
    public static final String ClassNameProperty = ".class";

    /**
     * The singleton instance of the ComponentFactory.
     */
    private static ComponentFactory singleton;

    protected ComponentFactory() {}

    /**
     * Method call to retrieve the singleton instance of the
     * ComponentFactory.
     * 
     * @return ComponentFactory.
     */
    protected static ComponentFactory getInstance() {
        if (singleton == null) {
            singleton = new ComponentFactory();
        }
        return singleton;
    }

    /**
     * Set the singleton instance of the ComponentFactory.
     * 
     * @param cf
     */
    protected static void setInstance(ComponentFactory cf) {
        singleton = cf;
    }

    /**
     * Given a Vector of marker name Strings, and a Properties object,
     * look in the Properties object for the markerName.class property
     * to get a class name to create each object. Then, if the new
     * objects are PropertyConsumers, use the marker name as a
     * property prefix to get properties for that object out of the
     * Properties.
     * 
     * @param markerNames String of space separated marker names.
     * @param properties Properties object containing the details.
     * @return Vector containing the new Objects.
     */
    public static Vector create(Vector markerNames, Properties properties) {
        return getInstance()._create(markerNames, null, properties, null, false);
    }

    /**
     * Given a Vector of marker name Strings, and a Properties object,
     * look in the Properties object for the markerName.class property
     * to get a class name to create each object. Then, if the new
     * objects are PropertyConsumers, use the marker name as a
     * property prefix to get properties for that object out of the
     * Properties.
     * 
     * @param markerNames String of space separated marker names.
     * @param prefix The prefix that should be prepended to the marker
     *        names.
     * @param properties Properties object containing the details.
     * @return Vector containing the new Objects.
     */
    public static Vector create(Vector markerNames, String prefix,
                                Properties properties) {
        return getInstance()._create(markerNames,
                prefix,
                properties,
                null,
                false);
    }

    /**
     * Given a Vector of marker name Strings, and a Properties object,
     * look in the Properties object for the markerName.class property
     * to get a class name to create each object. Then, if the new
     * objects are PropertyConsumers, use the marker name as a
     * property prefix to get properties for that object out of the
     * Properties.
     * 
     * @param markerNames String of space separated marker names.
     * @param prefix The prefix that should be prepended to the marker
     *        names.
     * @param properties Properties object containing the details.
     * @param progressSupport ProgressSupport object to provide
     *        progress updates to. It's OK if this is null to not have
     *        progress events sent.
     * @return Vector containing the new Objects.
     */
    public static Vector create(Vector markerNames, String prefix,
                                Properties properties,
                                ProgressSupport progressSupport) {
        return getInstance()._create(markerNames,
                prefix,
                properties,
                progressSupport,
                false);
    }

    /**
     * Given a Vector of marker name Strings, and a Properties object,
     * look in the Properties object for the markerName.class property
     * to get a class name to create each object. Then, if the new
     * objects are PropertyConsumers, use the marker name as a
     * property prefix to get properties for that object out of the
     * Properties.
     * 
     * @param markerNames String of space separated marker names.
     * @param properties Properties object containing the details.
     * @param progressSupport ProgressSupport object to provide
     *        progress updates to. It's OK if this is null to not have
     *        progress events sent.
     * @return Vector containing the new Objects.
     */
    public static Vector create(Vector markerNames, Properties properties,
                                ProgressSupport progressSupport) {
        return getInstance()._create(markerNames,
                null,
                properties,
                progressSupport,
                false);
    }

    /**
     * Given a Vector of marker name Strings, and a Properties object,
     * look in the Properties object for the markerName.class property
     * to get a class name to create each object. Then, if the new
     * objects are PropertyConsumers, use the marker name as a
     * property prefix to get properties for that object out of the
     * Properties.
     * 
     * @param markerNames String of space separated marker names.
     * @param properties Properties object containing the details.
     * @param progressSupport ProgressSupport object to provide
     *        progress updates to. It's OK if this is null to not have
     *        progress events sent.
     * @param matchInOutVectorSize if true, then if there is any
     *        trouble creating an object, it's marker name will be
     *        placed in the returned vector instead of a component. If
     *        false, only valid objects will be returned in the
     *        vector.
     * @return Vector containing the new Objects. If a component could
     *         not be created, the markerName is returned in its
     *         place, so you can figure out which one couldn't be
     *         created. In any case, the size of the returned vector
     *         is the same size as the markerNames vector, so you can
     *         figure out which markerNames go with which objects.
     */
    public static Vector create(Vector markerNames, Properties properties,
                                ProgressSupport progressSupport,
                                boolean matchInOutVectorSize) {
        return getInstance()._create(markerNames,
                null,
                properties,
                progressSupport,
                matchInOutVectorSize);
    }

    /**
     * Given a Vector of marker name Strings, and a Properties object,
     * look in the Properties object for the markerName.class property
     * to get a class name to create each object. Then, if the new
     * objects are PropertyConsumers, use the marker name as a
     * property prefix to get properties for that object out of the
     * Properties.
     * 
     * @param markerNames String of space separated marker names.
     * @param prefix The prefix that should be prepended to the marker
     *        names.
     * @param properties Properties object containing the details.
     * @param progressSupport ProgressSupport object to provide
     *        progress updates to. It's OK if this is null to not have
     *        progress events sent.
     * @param matchInOutVectorSize if true, then if there is any
     *        trouble creating an object, it's marker name will be
     *        placed in the returned vector instead of a component. If
     *        false, only valid objects will be returned in the
     *        vector.
     * @return Vector containing the new Objects. If a component could
     *         not be created, the markerName is returned in its
     *         place, so you can figure out which one couldn't be
     *         created. In any case, the size of the returned vector
     *         is the same size as the markerNames vector, so you can
     *         figure out which markerNames go with which objects.
     */
    public static Vector create(Vector markerNames, String prefix,
                                Properties properties,
                                ProgressSupport progressSupport,
                                boolean matchInOutVectorSize) {

        return getInstance()._create(markerNames,
                prefix,
                properties,
                progressSupport,
                matchInOutVectorSize);
    }

    /**
     * Given a Vector of marker name Strings, and a Properties object,
     * look in the Properties object for the markerName.class property
     * to get a class name to create each object. Then, if the new
     * objects are PropertyConsumers, use the marker name as a
     * property prefix to get properties for that object out of the
     * Properties.
     * 
     * @param markerNames String of space separated marker names.
     * @param prefix The prefix that should be prepended to the marker
     *        names.
     * @param properties Properties object containing the details.
     * @param progressSupport ProgressSupport object to provide
     *        progress updates to. It's OK if this is null to not have
     *        progress events sent.
     * @param matchInOutVectorSize if true, then if there is any
     *        trouble creating an object, it's marker name will be
     *        placed in the returned vector instead of a component. If
     *        false, only valid objects will be returned in the
     *        vector.
     * @return Vector containing the new Objects. If a component could
     *         not be created, the markerName is returned in its
     *         place, so you can figure out which one couldn't be
     *         created. In any case, the size of the returned vector
     *         is the same size as the markerNames vector, so you can
     *         figure out which markerNames go with which objects.
     */
    protected Vector _create(Vector markerNames, String prefix,
                             Properties properties,
                             ProgressSupport progressSupport,
                             boolean matchInOutVectorSize) {

        int size = markerNames.size();
        Vector vector = new Vector(size);

        if (progressSupport != null) {
            progressSupport.fireUpdate(ProgressEvent.UPDATE,
                    "Creating Components",
                    100,
                    0);
        }

        for (int i = 0; i < size; i++) {
            String componentName = PropUtils.getScopedPropertyPrefix(prefix)
                    + (String) markerNames.elementAt(i);

            String classProperty = componentName + ClassNameProperty;
            String className = properties.getProperty(classProperty);

            if (className == null) {
                Debug.error("ComponentFactory.create: Failed to locate property \""
                        + componentName
                        + "\" with class \""
                        + classProperty
                        + "\"\n  Skipping component \"" + componentName + "\"");
                if (matchInOutVectorSize) {
                    vector.add(componentName);
                }
                continue;
            }

            if (progressSupport != null) {
                progressSupport.fireUpdate(ProgressEvent.UPDATE,
                        "Creating Components",
                        size,
                        i);
            }

            Object component = create(className, componentName, properties);

            if (component != null) {
                vector.add(component);
                if (Debug.debugging("componentfactory")) {
                    Debug.output("ComponentFactory: [" + className + "(" + i
                            + ")] created");
                }
            } else {
                if (matchInOutVectorSize) {
                    vector.add(componentName);
                }
                Debug.output("ComponentFactory: [" + componentName + " : "
                        + className + "(" + i + ")] NOT created. -- "
                        + "Set 'componentfactory' debug flag for details.");
            }
        }

        if (progressSupport != null) {
            progressSupport.fireUpdate(ProgressEvent.UPDATE,
                    "Configuring...",
                    size,
                    size);
        }
        return vector;
    }

    /**
     * Create a single object.
     * 
     * @param className Class name to instantiate, empty constructor.
     * @return object if all goes well, null if not.
     */
    public static Object create(String className) {
        return create(className, (Object[]) null, null, null);
    }

    /**
     * Create a single object.
     * 
     * @param className Class name to instantiate.
     * @param properties Properties to use to initalize the object, if
     *        the object is a PropertyConsumer.