https://eclipse.org/jetty/jetty-server: The core jetty server artifact. (Webtide) 
//
// ========================================================================
// Copyright (c) 1995-2020 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under
// the terms of the Eclipse Public License 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0
//
// This Source Code may also be made available under the following
// Secondary Licenses when the conditions for such availability set
// forth in the Eclipse Public License, v. 2.0 are satisfied:
// the Apache License v2.0 which is available at
// https://www.apache.org/licenses/LICENSE-2.0
//
// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
// ========================================================================
//

package org.eclipse.jetty.server.handler;

import java.io.IOException;

import jakarta.servlet.DispatcherType;
import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.eclipse.jetty.server.Handler;
import org.eclipse.jetty.server.HttpChannel;
import org.eclipse.jetty.server.HttpConnection;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.Response;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.util.annotation.ManagedObject;
import org.eclipse.jetty.util.component.ContainerLifeCycle;
import org.eclipse.jetty.util.component.Dumpable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


AbstractHandler.

A convenience implementation of Handler that uses the ContainerLifeCycle to provide:
    

  • start/stop behavior

  • a bean container

  • basic Dumpable support 
  • a Server reference 
  • optional error dispatch handling



/**
 * AbstractHandler.
 * <p>A convenience implementation of {@link Handler} that uses the
 * {@link ContainerLifeCycle} to provide:<ul>
 * <li>start/stop behavior
 * <li>a bean container
 * <li>basic {@link Dumpable} support
 * <li>a {@link Server} reference
 * <li>optional error dispatch handling
 * </ul>
 */
@ManagedObject("Jetty Handler")
public abstract class AbstractHandler extends ContainerLifeCycle implements Handler
{
    private static final Logger LOG = LoggerFactory.getLogger(AbstractHandler.class);

    private Server _server;

    public AbstractHandler()
    {
    }

    @Override
    public abstract void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException;

    
Deprecated error page generation

Params:
Throws:
  • IOException – if unable to handle the request or response processing
  • ServletException – if unable to handle the request or response due to underlying servlet issue
/**
     * Deprecated error page generation
     * @param target The target of the request - either a URI or a name.
     * @param baseRequest The original unwrapped request object.
     * @param request The request either as the {@link Request} object or a wrapper of that request. The
     * <code>{@link HttpConnection#getCurrentConnection()}.{@link HttpConnection#getHttpChannel() getHttpChannel()}.{@link HttpChannel#getRequest() getRequest()}</code>
     * method can be used access the Request object if required.
     * @param response The response as the {@link Response} object or a wrapper of that request. The
     * <code>{@link HttpConnection#getCurrentConnection()}.{@link HttpConnection#getHttpChannel() getHttpChannel()}.{@link HttpChannel#getResponse() getResponse()}</code>
     * method can be used access the Response object if required.
     * @throws IOException if unable to handle the request or response processing
     * @throws ServletException if unable to handle the request or response due to underlying servlet issue
     */
    @Deprecated
    protected void doError(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
    {
        Object o = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
        int code = (o instanceof Integer) ? ((Integer)o).intValue() : (o != null ? Integer.parseInt(o.toString()) : 500);
        response.setStatus(code);
        baseRequest.setHandled(true);
    }

    @Override
    protected void doStart() throws Exception
    {
        if (LOG.isDebugEnabled())
            LOG.debug("starting {}", this);
        if (_server == null)
            LOG.warn("No Server set for {}", this);
        super.doStart();
    }

    @Override
    protected void doStop() throws Exception
    {
        if (LOG.isDebugEnabled())
            LOG.debug("stopping {}", this);
        super.doStop();
    }

    @Override
    public void setServer(Server server)
    {
        if (_server == server)
            return;
        if (isStarted())
            throw new IllegalStateException(getState());
        _server = server;
    }

    @Override
    public Server getServer()
    {
        return _server;
    }

    @Override
    public void destroy()
    {
        if (!isStopped())
            throw new IllegalStateException("!STOPPED");
        super.destroy();
    }

    
An extension of AbstractHandler that handles DispatcherType.ERROR dispatches. 
 DispatcherType.ERROR dispatches are handled by calling the AbstractHandler.doError(String, Request, HttpServletRequest, HttpServletResponse) method. All other dispatches are passed to the abstract doNonErrorHandle(String, Request, HttpServletRequest, HttpServletResponse) method, which should be implemented with specific handler behavior 
Deprecated:This class is no longer required as ERROR dispatch is only done if there is an error page target.
/**
     * An extension of AbstractHandler that handles {@link DispatcherType#ERROR} dispatches.
     * <p>
     * {@link DispatcherType#ERROR} dispatches are handled by calling the {@link #doError(String, Request, HttpServletRequest, HttpServletResponse)}
     * method.  All other dispatches are passed to the abstract {@link #doNonErrorHandle(String, Request, HttpServletRequest, HttpServletResponse)}
     * method, which should be implemented with specific handler behavior
     * @deprecated This class is no longer required as ERROR dispatch is only done if there is an error page target.
     */
    @Deprecated
    public abstract static class ErrorDispatchHandler extends AbstractHandler
    {
        @Override
        public final void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
        {
            if (baseRequest.getDispatcherType() == DispatcherType.ERROR)
                doError(target, baseRequest, request, response);
            else
                doNonErrorHandle(target, baseRequest, request, response);
        }

        
Params:
Throws:
  • IOException – if unable to handle the request or response processing
  • ServletException – if unable to handle the request or response due to underlying servlet issue
/**
         * Called by {@link #handle(String, Request, HttpServletRequest, HttpServletResponse)}
         * for all non-{@link DispatcherType#ERROR} dispatches.
         *
         * @param target The target of the request - either a URI or a name.
         * @param baseRequest The original unwrapped request object.
         * @param request The request either as the {@link Request} object or a wrapper of that request. The
         * <code>{@link HttpConnection#getCurrentConnection()}.{@link HttpConnection#getHttpChannel() getHttpChannel()}.{@link HttpChannel#getRequest() getRequest()}</code>
         * method can be used access the Request object if required.
         * @param response The response as the {@link Response} object or a wrapper of that request. The
         * <code>{@link HttpConnection#getCurrentConnection()}.{@link HttpConnection#getHttpChannel() getHttpChannel()}.{@link HttpChannel#getResponse() getResponse()}</code>
         * method can be used access the Response object if required.
         * @throws IOException if unable to handle the request or response processing
         * @throws ServletException if unable to handle the request or response due to underlying servlet issue
         */
        @Deprecated
        protected abstract void doNonErrorHandle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException;
    }
}