org.eclipse.jetty.server.handler.HotSwapHandler Maven / Gradle / Ivy

// 
// ========================================================================
// Copyright (c) 1995-2022 Mort Bay Consulting Pty Ltd and others.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// 
// The Eclipse Public License is available at
// http://www.eclipse.org/legal/epl-v10.html
// 
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// 
// You may elect to redistribute this code under either of these licenses.
// ========================================================================
// 
package org.eclipse.jetty.server.handler;

import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.Server;

/**
 *  A HandlerContainer that allows a hot swap of a wrapped handler.
 *
 * @deprecated The Eclipse Jetty and Apache Felix Http Jetty packages are no longer supported.
 */
@Deprecated(since = "2021-05-27")
public class HotSwapHandler extends AbstractHandlerContainer {

    private volatile Handler _handler;

    /**
     */
    public HotSwapHandler() {
    }

    /**
     * @return Returns the handlers.
     */
    public Handler getHandler() {
        return _handler;
    }

    /**
     * @return Returns the handlers.
     */
    @Override
    public Handler[] getHandlers() {
        Handler handler = _handler;
        if (handler == null)
            return new Handler[0];
        return new Handler[] { handler };
    }

    /**
     * @param handler Set the {@link Handler} which should be wrapped.
     */
    public void setHandler(Handler handler) {
        try {
            Server server = getServer();
            if (handler != null)
                handler.setServer(server);
            updateBean(_handler, handler, true);
            _handler = handler;
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /*
     * @see org.eclipse.thread.AbstractLifeCycle#doStart()
     */
    @Override
    protected void doStart() throws Exception {
        super.doStart();
    }

    /*
     * @see org.eclipse.thread.AbstractLifeCycle#doStop()
     */
    @Override
    protected void doStop() throws Exception {
        super.doStop();
    }

    /*
     * @see org.eclipse.jetty.server.server.EventHandler#handle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    @Override
    public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
        Handler handler = _handler;
        if (handler != null && isStarted() && handler.isStarted()) {
            handler.handle(target, baseRequest, request, response);
        }
    }

    @Override
    protected void expandChildren(List list, Class byClass) {
        Handler handler = _handler;
        if (handler != null)
            expandHandler(handler, list, byClass);
    }

    @Override
    public void destroy() {
        if (!isStopped())
            throw new IllegalStateException("!STOPPED");
        Handler child = getHandler();
        if (child != null) {
            setHandler(null);
            child.destroy();
        }
        super.destroy();
    }
}