BrowserFactory.java

package sai;
import org.web3d.x3d.sai.*;
import java.util.*;
import java.io.*;
import java.applet.*;
import java.net.*;

public class BrowserFactory {

        private static BrowserFactoryImpl freewrlFactory;
        private static Properties freewrlProperties;

        static {
        
                freewrlProperties = new Properties();

                InputStream is = BrowserFactory.class.getClassLoader().getResourceAsStream("freewrlsai.properties");

                if (is == null) {
                        freewrlProperties.put("factory", "sai.FreeWRLFactory");
                } else {
                        try {
                                freewrlProperties.load(is);
                        } catch (IOException e) {
                                System.out.println(e);
                        }
                }
        }

        
        private BrowserFactory() {

        }

        public static void setBrowserFactoryImpl(BrowserFactoryImpl fac) throws IllegalArgumentException, X3DException, SecurityException {
                if (freewrlFactory != null) {
                        throw new X3DException("Factory has already been defined");
                }

                if (fac == null) {
                        throw new IllegalArgumentException("Null factory passed to setBrowserFactoryImpl");
                }
        
                freewrlFactory = fac;
        }

        public static X3DComponent createX3DComponent(Map params) throws NotSupportedException {
                if (freewrlFactory == null)
                        loadFactory();

                return freewrlFactory.createX3DComponent(params);
        }
        
        public static ExternalBrowser getBrowser(Applet applet) throws NotSupportedException, NoSuchBrowserException {
                if (freewrlFactory == null)
                        loadFactory();

                ExternalBrowser b = freewrlFactory.getBrowser(applet);

                if (b == null) {
                        throw new NoSuchBrowserException("getBrowser(Applet): no such browser found");
                }

                return b;
        }

        public static ExternalBrowser getBrowser(Applet applet, String frameName, int index) throws NotSupportedException, NoSuchBrowserException {
                if (freewrlFactory == null)
                        loadFactory();

                ExternalBrowser b = freewrlFactory.getBrowser(applet);

                if (b == null) {
                        throw new NoSuchBrowserException("getBrowser(Applet, String, int): no such browser found");
                }

                return b;

        }

        public static ExternalBrowser getBrowser(InetAddress address, int port) throws NotSupportedException, NoSuchBrowserException, UnknownHostException, ConnectionException {
                if (freewrlFactory == null)
                        loadFactory();

                return freewrlFactory.getBrowser(address, port);
        }

        private static void loadFactory() {
                try {
                        String factoryClassName = (String) freewrlProperties.getProperty("factory");
                        Class  factoryClass = Class.forName(factoryClassName);
                        freewrlFactory = (BrowserFactoryImpl)factoryClass.newInstance(); 
                } catch (Exception e) {
                        System.out.println(e);
                }
        }
}