Mercurial Hosting > luan

//
//  ========================================================================
//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  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.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.eclipse.jetty.http.HttpHeaders;
import org.eclipse.jetty.http.HttpMethods;
import org.eclipse.jetty.http.HttpStatus;
import org.eclipse.jetty.http.MimeTypes;
import org.eclipse.jetty.server.AbstractHttpConnection;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.util.ByteArrayISO8859Writer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/* ------------------------------------------------------------ */
/** Handler for Error pages
 * An ErrorHandler is registered with {@link ContextHandler#setErrorHandler(ErrorHandler)} or
 * {@link org.eclipse.jetty.server.Server#addBean(Object)}.
 * It is called by the HttpResponse.sendError method to write a error page.
 *
 */
public class ErrorHandler extends AbstractHandler
{
	private static final Logger LOG = LoggerFactory.getLogger(ErrorHandler.class);
	public final static String ERROR_PAGE="org.eclipse.jetty.server.error_page";

	boolean _showStacks=true;
	boolean _showMessageInTitle=true;
	String _cacheControl="must-revalidate,no-cache,no-store";

	/* ------------------------------------------------------------ */
	/*
	 * @see org.eclipse.jetty.server.server.Handler#handle(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse, int)
	 */
	public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException
	{
		AbstractHttpConnection connection = AbstractHttpConnection.getCurrentConnection();
		String method = request.getMethod();
		if(!method.equals(HttpMethods.GET) && !method.equals(HttpMethods.POST) && !method.equals(HttpMethods.HEAD))
		{
			connection.getRequest().setHandled(true);
			return;
		}

		connection.getRequest().setHandled(true);
		response.setContentType(MimeTypes.TEXT_HTML_8859_1);
		if (_cacheControl!=null)
			response.setHeader(HttpHeaders.CACHE_CONTROL, _cacheControl);
		ByteArrayISO8859Writer writer= new ByteArrayISO8859Writer(4096);
		handleErrorPage(request, writer, connection.getResponse().getStatus(), connection.getResponse().getReason());
		writer.flush();
		response.setContentLength(writer.size());
		writer.writeTo(response.getOutputStream());
		writer.destroy();
	}

	/* ------------------------------------------------------------ */
	protected void handleErrorPage(HttpServletRequest request, Writer writer, int code, String message)
		throws IOException
	{
		writeErrorPage(request, writer, code, message, _showStacks);
	}

	/* ------------------------------------------------------------ */
	protected void writeErrorPage(HttpServletRequest request, Writer writer, int code, String message, boolean showStacks)
		throws IOException
	{
		if (message == null)
			message=HttpStatus.getMessage(code);

		writer.write("<html>\n<head>\n");
		writeErrorPageHead(request,writer,code,message);
		writer.write("</head>\n<body>");
		writeErrorPageBody(request,writer,code,message,showStacks);
		writer.write("\n</body>\n</html>\n");
	}

	/* ------------------------------------------------------------ */
	protected void writeErrorPageHead(HttpServletRequest request, Writer writer, int code, String message)
		throws IOException
		{
		writer.write("<meta http-equiv=\"Content-Type\" content=\"text/html; charset=ISO-8859-1\"/>\n");
		writer.write("<title>Error ");
		writer.write(Integer.toString(code));

		if (_showMessageInTitle)
		{
			writer.write(' ');
			write(writer,message);
		}
		writer.write("</title>\n");
	}

	/* ------------------------------------------------------------ */
	protected void writeErrorPageBody(HttpServletRequest request, Writer writer, int code, String message, boolean showStacks)
		throws IOException
	{
		String uri= request.getRequestURI();

		writeErrorPageMessage(request,writer,code,message,uri);
		if (showStacks)
			writeErrorPageStacks(request,writer);
		writer.write("<hr /><i><small>Powered by Jetty://</small></i>");
		for (int i= 0; i < 20; i++)
			writer.write("<br/>                                                \n");
	}

	/* ------------------------------------------------------------ */
	protected void writeErrorPageMessage(HttpServletRequest request, Writer writer, int code, String message,String uri)
	throws IOException
	{
		writer.write("<h2>HTTP ERROR ");
		writer.write(Integer.toString(code));
		writer.write("</h2>\n<p>Problem accessing ");
		write(writer,uri);
		writer.write(". Reason:\n<pre>    ");
		write(writer,message);
		writer.write("</pre></p>");
	}

	/* ------------------------------------------------------------ */
	protected void writeErrorPageStacks(HttpServletRequest request, Writer writer)
		throws IOException
	{
		Throwable th = (Throwable)request.getAttribute("javax.servlet.error.exception");
		while(th!=null)
		{
			writer.write("<h3>Caused by:</h3><pre>");
			StringWriter sw = new StringWriter();
			PrintWriter pw = new PrintWriter(sw);
			th.printStackTrace(pw);
			pw.flush();
			write(writer,sw.getBuffer().toString());
			writer.write("</pre>\n");

			th =th.getCause();
		}
	}


	/* ------------------------------------------------------------ */
	/** Get the cacheControl.
	 * @return the cacheControl header to set on error responses.
	 */
	public String getCacheControl()
	{
		return _cacheControl;
	}

	/* ------------------------------------------------------------ */
	/** Set the cacheControl.
	 * @param cacheControl the cacheControl header to set on error responses.
	 */
	public void setCacheControl(String cacheControl)
	{
		_cacheControl = cacheControl;
	}

	/* ------------------------------------------------------------ */
	/**
	 * @return True if stack traces are shown in the error pages
	 */
	public boolean isShowStacks()
	{
		return _showStacks;
	}

	/* ------------------------------------------------------------ */
	/**
	 * @param showStacks True if stack traces are shown in the error pages
	 */
	public void setShowStacks(boolean showStacks)
	{
		_showStacks = showStacks;
	}

	/* ------------------------------------------------------------ */
	/**
	 * @param showMessageInTitle if true, the error message appears in page title
	 */
	public void setShowMessageInTitle(boolean showMessageInTitle)
	{
		_showMessageInTitle = showMessageInTitle;
	}


	/* ------------------------------------------------------------ */
	public boolean getShowMessageInTitle()
	{
		return _showMessageInTitle;
	}

	/* ------------------------------------------------------------ */
	protected void write(Writer writer,String string)
		throws IOException
	{
		if (string==null)
			return;

		for (int i=0;i<string.length();i++)
		{
			char c=string.charAt(i);

			switch(c)
			{
				case '&' :
					writer.write("&amp;");
					break;
				case '<' :
					writer.write("&lt;");
					break;
				case '>' :
					writer.write("&gt;");
					break;

				default:
					if (Character.isISOControl(c) && !Character.isWhitespace(c))
						writer.write('?');
					else
						writer.write(c);
			}
		}
	}
}
author	Franklin Schmidt <fschmidt@gmail.com>
date	Thu, 06 Oct 2016 23:43:36 -0600
parents	0048a843297a
children