org.eclipse.jetty.server.handler.ErrorHandler Maven / Gradle / Ivy
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//
// ========================================================================
// Copyright (c) 1995-2016 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 java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.eclipse.jetty.http.HttpFields;
import org.eclipse.jetty.http.HttpHeader;
import org.eclipse.jetty.http.HttpMethod;
import org.eclipse.jetty.http.HttpStatus;
import org.eclipse.jetty.http.MimeTypes;
import org.eclipse.jetty.server.Dispatcher;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.StringUtil;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
/* ------------------------------------------------------------ */
/** 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 via {@link #handle(String, Request, HttpServletRequest, HttpServletResponse)}
* or via {@link #badMessageError(int, String, HttpFields)} for bad requests for which a dispatch cannot be done.
*
*/
public class ErrorHandler extends AbstractHandler
{
private static final Logger LOG = Log.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)
*/
@Override
public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response) throws IOException
{
String method = request.getMethod();
if (!HttpMethod.GET.is(method) && !HttpMethod.POST.is(method) && !HttpMethod.HEAD.is(method))
{
baseRequest.setHandled(true);
return;
}
if (this instanceof ErrorPageMapper)
{
String error_page=((ErrorPageMapper)this).getErrorPage(request);
if (error_page!=null && request.getServletContext()!=null)
{
String old_error_page=(String)request.getAttribute(ERROR_PAGE);
if (old_error_page==null || !old_error_page.equals(error_page))
{
request.setAttribute(ERROR_PAGE, error_page);
Dispatcher dispatcher = (Dispatcher) request.getServletContext().getRequestDispatcher(error_page);
try
{
if(dispatcher!=null)
{
dispatcher.error(request, response);
return;
}
LOG.warn("No error page "+error_page);
}
catch (ServletException e)
{
LOG.warn(Log.EXCEPTION, e);
return;
}
}
}
else
{
if (LOG.isDebugEnabled())
{
LOG.debug("No Error Page mapping for request({} {}) (using default)",request.getMethod(),request.getRequestURI());
}
}
}
if (_cacheControl != null)
response.setHeader(HttpHeader.CACHE_CONTROL.asString(), _cacheControl);
generateAcceptableResponse(baseRequest,request,response,response.getStatus(),baseRequest.getResponse().getReason());
}
/**
* Generate an acceptable error response.
* This method is called to generate an Error page of a mime type that is
* acceptable to the user-agent. The Accept header is evaluated in
* quality order and the method
* {@link #generateAcceptableResponse(Request, HttpServletRequest, HttpServletResponse, int, String, String)}
* is called for each mimetype until {@link Request#isHandled()} is true.
* @param baseRequest The base request
* @param request The servlet request (may be wrapped)
* @param response The response (may be wrapped)
* @throws IOException if the response cannot be generated
*/
protected void generateAcceptableResponse(Request baseRequest, HttpServletRequest request, HttpServletResponse response, int code, String message)
throws IOException
{
List acceptable=baseRequest.getHttpFields().getQualityCSV(HttpHeader.ACCEPT);
if (acceptable.isEmpty() && !baseRequest.getHttpFields().contains(HttpHeader.ACCEPT))
generateAcceptableResponse(baseRequest,request,response,code,message,MimeTypes.Type.TEXT_HTML.asString());
else
{
for (String mimeType:acceptable)
{
generateAcceptableResponse(baseRequest,request,response,code,message,mimeType);
if (baseRequest.isHandled())
return;
}
}
baseRequest.setHandled(true);
}
/**
* Returns an acceptable writer for an error page.
* Uses the user-agent's Accept-Charset to get response
* {@link Writer}. The acceptable charsets are tested in quality order
* if they are known to the JVM and the first known is set on
* {@link HttpServletResponse#setCharacterEncoding(String)} and the
* {@link HttpServletResponse#getWriter()} method used to return a writer.
* If there is no Accept-Charset header then
* ISO-8859-1 is used. If '*' is the highest quality known
* charset, then utf-8 is used.
*
* @param baseRequest The base request
* @param request The servlet request (may be wrapped)
* @param response The response (may be wrapped)
* @return A {@link Writer} if there is a known acceptable charset or null
* @throws IOException if a Writer cannot be returned
*/
protected Writer getAcceptableWriter(Request baseRequest, HttpServletRequest request, HttpServletResponse response)
throws IOException
{
List acceptable=baseRequest.getHttpFields().getQualityCSV(HttpHeader.ACCEPT_CHARSET);
if (acceptable.isEmpty())
{
response.setCharacterEncoding(StandardCharsets.ISO_8859_1.name());
return response.getWriter();
}
for (String charset:acceptable)
{
try
{
if ("*".equals(charset))
response.setCharacterEncoding(StandardCharsets.UTF_8.name());
else
response.setCharacterEncoding(Charset.forName(charset).name());
return response.getWriter();
}
catch(Exception e)
{
LOG.ignore(e);
}
}
return null;
}
/* ------------------------------------------------------------ */
/** Generate an acceptable error response for a mime type.
* This method is called for each mime type in the users agent's
* Accept header, until {@link Request#isHandled()} is true and a
* response of the appropriate type is generated.
*
* @param baseRequest The base request
* @param request The servlet request (may be wrapped)
* @param response The response (may be wrapped)
* @param mimeType The mimetype to generate (may be */*or other wildcard)
* @throws IOException if a response cannot be generated
*/
protected void generateAcceptableResponse(Request baseRequest, HttpServletRequest request, HttpServletResponse response, int code, String message, String mimeType)
throws IOException
{
switch(mimeType)
{
case "text/html":
case "text/*":
case "*/*":
{
baseRequest.setHandled(true);
Writer writer = getAcceptableWriter(baseRequest,request,response);
if (writer!=null)
{
response.setContentType(MimeTypes.Type.TEXT_HTML.asString());
handleErrorPage(request, writer, code, message);
}
}
}
}
/* ------------------------------------------------------------ */
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("\n
\n");
writeErrorPageHead(request,writer,code,message);
writer.write("\n");
writeErrorPageBody(request,writer,code,message,showStacks);
writer.write("\n\n\n");
}
/* ------------------------------------------------------------ */
protected void writeErrorPageHead(HttpServletRequest request, Writer writer, int code, String message)
throws IOException
{
writer.write("\n");
writer.write("Error ");
writer.write(Integer.toString(code));
if (_showMessageInTitle)
{
writer.write(' ');
write(writer,message);
}
writer.write(" \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);
Request.getBaseRequest(request).getHttpChannel().getHttpConfiguration()
.writePoweredBy(writer,"
","
\n");
}
/* ------------------------------------------------------------ */
protected void writeErrorPageMessage(HttpServletRequest request, Writer writer, int code, String message,String uri)
throws IOException
{
writer.write("HTTP ERROR ");
writer.write(Integer.toString(code));
writer.write("
\nProblem accessing ");
write(writer,uri);
writer.write(". Reason:\n
");
write(writer,message);
writer.write("");
}
/* ------------------------------------------------------------ */
protected void writeErrorPageStacks(HttpServletRequest request, Writer writer)
throws IOException
{
Throwable th = (Throwable)request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
while(th!=null)
{
writer.write("Caused by:
");
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
th.printStackTrace(pw);
pw.flush();
write(writer,sw.getBuffer().toString());
writer.write("\n");
th =th.getCause();
}
}
/* ------------------------------------------------------------ */
/** Bad Message Error body
* Generate a error response body to be sent for a bad message.
* In this case there is something wrong with the request, so either
* a request cannot be built, or it is not safe to build a request.
* This method allows for a simple error page body to be returned
* and some response headers to be set.
* @param status The error code that will be sent
* @param reason The reason for the error code (may be null)
* @param fields The header fields that will be sent with the response.
* @return The content as a ByteBuffer, or null for no body.
*/
public ByteBuffer badMessageError(int status, String reason, HttpFields fields)
{
if (reason==null)
reason=HttpStatus.getMessage(status);
fields.put(HttpHeader.CONTENT_TYPE,MimeTypes.Type.TEXT_HTML_8859_1.asString());
return BufferUtil.toBuffer("
Bad Message " + status + "
reason: " + reason + "
");
}
/* ------------------------------------------------------------ */
/** 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;
writer.write(StringUtil.sanitizeXmlString(string));
}
/* ------------------------------------------------------------ */
public interface ErrorPageMapper
{
String getErrorPage(HttpServletRequest request);
}
/* ------------------------------------------------------------ */
public static ErrorHandler getErrorHandler(Server server, ContextHandler context)
{
ErrorHandler error_handler=null;
if (context!=null)
error_handler=context.getErrorHandler();
if (error_handler==null && server!=null)
error_handler = server.getBean(ErrorHandler.class);
return error_handler;
}
}