UIWindowFactory.java

/*
 * Copyright to the original author or authors.
 *
 * Licensed 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.rioproject.serviceui;

import net.jini.core.lookup.ServiceItem;
import net.jini.lookup.ui.factory.JWindowFactory;

import javax.swing.*;
import java.awt.*;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.AccessController;
import java.security.PrivilegedAction;

/**
 * The UIWindowFactory class is a helper for use with the ServiceUI
 *
 * @author Dennis Reedy
 */
public class UIWindowFactory implements JWindowFactory, Serializable {
    private String className;
    private URL[] exportURL;

    public UIWindowFactory(URL exportUrl, String className) {
        this.className = className;
        this.exportURL = new URL[]{exportUrl};
    }

    public UIWindowFactory(URL[] exportURL, String className) {
        this.className = className;
        this.exportURL = exportURL;
    }

    public JWindow getJWindow(Object roleObject, Frame parent) {
        if(!(roleObject instanceof ServiceItem)) {
            throw new IllegalArgumentException("ServiceItem required");
        }
        JWindow component ;
        try {
            component = (JWindow)loadComponent(roleObject, parent);
        } catch(Throwable t) {
            if(t.getCause() != null)
                t = t.getCause();
            IllegalArgumentException e = 
                new IllegalArgumentException("Unable to instantiate ServiceUI :"
                                               + t.getClass().getName()
                                               + ": "
                                               + t.getLocalizedMessage());
            e.initCause(t);
            throw e;
        }
        return(component);
    }

    public JWindow getJWindow(Object roleObject, Window parent) {
        if(!(roleObject instanceof ServiceItem)) {
            throw new IllegalArgumentException("ServiceItem required");
        }
        JWindow component;
        try {
            component = (JWindow)loadComponent(roleObject, parent);
        } catch(Throwable t) {
            if(t.getCause() != null)
                t = t.getCause();
            IllegalArgumentException e = 
                new IllegalArgumentException("Unable to instantiate ServiceUI :"
                                               + t.getClass().getName()
                                               + ": "
                                               + t.getLocalizedMessage());
            e.initCause(t);
            throw e;
        }
        return(component);
    }

    public JWindow getJWindow(Object roleObject) {
        if(!(roleObject instanceof ServiceItem)) {
            throw new IllegalArgumentException("ServiceItem required");
        }
        JWindow component;
        try {
            component = (JWindow)loadComponent(roleObject, null);
        } catch(Throwable t) {
            if(t.getCause() != null)
                t = t.getCause();
            IllegalArgumentException e = 
                new IllegalArgumentException("Unable to instantiate ServiceUI :"
                                               + t.getClass().getName()
                                               + ": "
                                               + t.getLocalizedMessage());
            e.initCause(t);
            throw e;
        }
        return(component);
    }

    private Object loadComponent(Object roleObject, Object param)
        throws Exception {
        ClassLoader cl = ((ServiceItem)roleObject).service.getClass().getClassLoader();
        Object component;
        Object instanceObj;
        final URLClassLoader uiLoader = URLClassLoader.newInstance(exportURL,
                                                                   cl);
        final Thread currentThread = Thread.currentThread();
        AccessController.doPrivileged(new PrivilegedAction<Void>() {
            public Void run() {
                currentThread.setContextClassLoader(uiLoader);
                return (null);
            }
        });
        Class clazz = uiLoader.loadClass(className);
        Constructor constructor;
        if(param == null) {
            constructor = clazz.getConstructor(Object.class);
            instanceObj = constructor.newInstance(roleObject);
        } else if(param instanceof Window) {
            constructor = clazz.getConstructor(Object.class,
                                               Window.class);
            instanceObj = constructor.newInstance(roleObject,
                                                  param);
        } else {
            constructor = clazz.getConstructor(Object.class,
                                               Frame.class);
            instanceObj = constructor.newInstance(roleObject,
                                                  param);
        }
        component = instanceObj;
        return (component);
    }
}