defaultusernamestore.java

java实现浏览器等本地桌面的功能

/*
 * $Id: DefaultUserNameStore.java,v 1.4 2005/10/10 18:02:49 rbair Exp $
 *
 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 */

package org.jdesktop.swingx.auth;

import java.beans.PropertyChangeSupport;
import java.util.prefs.Preferences;
import org.jdesktop.swingx.JXLoginPanel;

/**
 * Saves the user names in Preferences. Because any string could be part
 * of the user name, for every user name that must be saved a new Preferences
 * key/value pair must be stored.
 *
 * @author Bino George
 * @author rbair
 */
public class DefaultUserNameStore extends UserNameStore {
    /**
     * The key for one of the preferences
     */
        private static final String USER_KEY = "usernames";
    /**
     */
    private static final String NUM_KEY = "usernames.length";
    /**
     * The preferences node
     */
    private Preferences prefs;
    /**
     * A name that is used when retrieving preferences. By default, the
     * app name is "default&quot. This should be set by the application
     * if the application wants it's own list of user names.
     */
        private String appNameForPreferences = "default";
    /**
     * Contains the user names. Since the list of user names is not
     * frequently updated, there is no penalty in storing the values
     * in an array.
     */
    private String[] userNames;
    /**
     * Used for propogating bean changes
     */
    private PropertyChangeSupport pcs;

    /**
     * Creates a new instance of DefaultUserNameStore
     */
    public DefaultUserNameStore() {
        pcs = new PropertyChangeSupport(this);
        userNames = new String[0];
    }

    public void loadUserNames() {
        initPrefs();
        if (prefs != null) {
            String numPrefix = getNumPrefix();
            int n = prefs.getInt(numPrefix, 0);
            String valuePrefix = getValuePrefix();
            String[] names = new String[n];
            for (int i = 0; i < n; i++) {
                names[i] = prefs.get(valuePrefix + "." + i, null);
            }
            setUserNames(names);
        }
    }

    public void saveUserNames() {
        initPrefs();
        if (prefs != null) {
            String numPrefix = getNumPrefix();
            String valuePrefix = getValuePrefix();
            prefs.putInt(numPrefix, userNames.length);
            for (int i = 0; i < userNames.length; i++) {
                prefs.put(valuePrefix + "." + i, userNames[i]);
            }
        }
    }

    public String[] getUserNames() {
        return userNames;
    }

    public void setUserNames(String[] userNames) {
        if (this.userNames != userNames) {
            String[] old = this.userNames;
            this.userNames = userNames == null ? new String[0] : userNames;
            pcs.firePropertyChange("userNames", old, this.userNames);
        }
    }

        /**
         * Add a username to the store.
         * @param name
         */
        public void addUserName(String name) {
                if (!containsUserName(name)) {
            String[] newNames = new String[userNames.length + 1];
            for (int i=0; i<userNames.length; i++) {
                newNames[i] = userNames[i];
            }
            newNames[newNames.length - 1] = name;
            setUserNames(newNames);
                }
        }

        /**
         * Removes a username from the list.
         *
         * @param name
         */
        public void removeUserName(String name) {
                if (containsUserName(name)) {
            String[] newNames = new String[userNames.length - 1];
            int index = 0;
            for (String s : userNames) {
                if (!s.equals(name)) {
                    newNames[index++] = s;
                }
            }
            setUserNames(newNames);
                }
        }

    public boolean containsUserName(String name) {
        for (String s : userNames) {
            if (s.equals(name)) {
                return true;
            }
        }
        return false;
    }

        /**
         * @return Returns the appNameForPreferences.
         */
        public String getAppNameForPreferences() {
                return appNameForPreferences;
        }

        /**
         * @param appNameForPreferences The appNameForPreferences to set.
         */
        public void setAppNameForPreferences(String appNameForPreferences) {
        if (this.appNameForPreferences != appNameForPreferences) {
            String old = this.appNameForPreferences;
            this.appNameForPreferences = appNameForPreferences;
            pcs.firePropertyChange("appNameForPreferences", old, appNameForPreferences);
            prefs = null;
            loadUserNames();
        }
        }

        private String getNumPrefix() {
                return this.getClass().getName() + "." + getAppNameForPreferences()
                                + "." + NUM_KEY;
        }

        private String getValuePrefix() {
                return this.getClass().getName() + "." + getAppNameForPreferences()
                                + "." + USER_KEY;
        }

    private void initPrefs() {
        if (prefs == null) {
            prefs = Preferences.userNodeForPackage(JXLoginPanel.class);
        }
    }
}