//
// ========================================================================
// Copyright (c) 1995-2017 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.servlet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import org.eclipse.jetty.server.Dispatcher;
import org.eclipse.jetty.server.handler.ContextHandler;
import org.eclipse.jetty.server.handler.ErrorHandler;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
/**
* An ErrorHandler that maps exceptions and status codes to URIs for dispatch using
* the internal ERROR style of dispatch.
*/
public class ErrorPageErrorHandler extends ErrorHandler implements ErrorHandler.ErrorPageMapper
{
public final static String GLOBAL_ERROR_PAGE = "org.eclipse.jetty.server.error_page.global";
private static final Logger LOG = Log.getLogger(ErrorPageErrorHandler.class);
private enum PageLookupTechnique
{
THROWABLE, STATUS_CODE, GLOBAL
}
protected ServletContext _servletContext;
private final Map<String, String> _errorPages = new HashMap<>(); // code or exception to URL
private final List<ErrorCodeRange> _errorPageList = new ArrayList<>(); // list of ErrorCode by range
@Override
public String getErrorPage(HttpServletRequest request)
{
String error_page = null;
PageLookupTechnique pageSource = null;
Class<?> matchedThrowable = null;
Throwable th = (Throwable)request.getAttribute(Dispatcher.ERROR_EXCEPTION);
// Walk the cause hierarchy
while (error_page == null && th != null)
{
pageSource = PageLookupTechnique.THROWABLE;
Class<?> exClass = th.getClass();
error_page = _errorPages.get(exClass.getName());
// walk the inheritance hierarchy
while (error_page == null)
{
exClass = exClass.getSuperclass();
if (exClass == null)
break;
error_page = _errorPages.get(exClass.getName());
}
if (error_page != null)
matchedThrowable = exClass;
th = (th instanceof ServletException) ? ((ServletException)th).getRootCause() : null;
}
Integer errorStatusCode = null;
if (error_page == null)
{
pageSource = PageLookupTechnique.STATUS_CODE;
// look for an exact code match
errorStatusCode = (Integer)request.getAttribute(Dispatcher.ERROR_STATUS_CODE);
if (errorStatusCode != null)
{
error_page = _errorPages.get(Integer.toString(errorStatusCode));
// if still not found
if (error_page == null)
{
// look for an error code range match.
for (ErrorCodeRange errCode : _errorPageList)
{
if (errCode.isInRange(errorStatusCode))
{
error_page = errCode.getUri();
break;
}
}
}
}
}
// Try servlet 3.x global error page.
if (error_page == null)
{
pageSource = PageLookupTechnique.GLOBAL;
error_page = _errorPages.get(GLOBAL_ERROR_PAGE);
}
if (LOG.isDebugEnabled())
{
StringBuilder dbg = new StringBuilder();
dbg.append("getErrorPage(");
dbg.append(request.getMethod()).append(' ');
dbg.append(request.getRequestURI());
dbg.append(") => error_page=").append(error_page);
switch (pageSource)
{
case THROWABLE:
dbg.append(" (using matched Throwable ");
dbg.append(matchedThrowable.getName());
dbg.append(" / actually thrown as ");
Throwable originalThrowable = (Throwable)request.getAttribute(Dispatcher.ERROR_EXCEPTION);
dbg.append(originalThrowable.getClass().getName());
dbg.append(')');
LOG.debug(dbg.toString(), th);
break;
case STATUS_CODE:
dbg.append(" (from status code ");
dbg.append(errorStatusCode);
dbg.append(')');
LOG.debug(dbg.toString());
break;
case GLOBAL:
dbg.append(" (from global default)");
LOG.debug(dbg.toString());
break;
}
}
return error_page;
}
public Map<String, String> getErrorPages()
{
return _errorPages;
}
/**
* @param errorPages a map of Exception class names or error codes as a string to URI string
*/
public void setErrorPages(Map<String, String> errorPages)
{
_errorPages.clear();
if (errorPages != null)
_errorPages.putAll(errorPages);
}
/**
* Adds ErrorPage mapping for an exception class.
* This method is called as a result of an exception-type element in a web.xml file
* or may be called directly
*
* @param exception The exception
* @param uri The URI of the error page.
*/
public void addErrorPage(Class<? extends Throwable> exception, String uri)
{
_errorPages.put(exception.getName(), uri);
}
/**
* Adds ErrorPage mapping for an exception class.
* This method is called as a result of an exception-type element in a web.xml file
* or may be called directly
*
* @param exceptionClassName The exception
* @param uri The URI of the error page.
*/
public void addErrorPage(String exceptionClassName, String uri)
{
_errorPages.put(exceptionClassName, uri);
}
/**
* Adds ErrorPage mapping for a status code.
* This method is called as a result of an error-code element in a web.xml file
* or may be called directly.
*
* @param code The HTTP status code to match
* @param uri The URI of the error page.
*/
public void addErrorPage(int code, String uri)
{
_errorPages.put(Integer.toString(code), uri);
}
/**
* Adds ErrorPage mapping for a status code range.
* This method is not available from web.xml and must be called directly.
*
* @param from The lowest matching status code
* @param to The highest matching status code
* @param uri The URI of the error page.
*/
public void addErrorPage(int from, int to, String uri)
{
_errorPageList.add(new ErrorCodeRange(from, to, uri));
}
@Override
protected void doStart() throws Exception
{
super.doStart();
_servletContext = ContextHandler.getCurrentContext();
}
private static class ErrorCodeRange
{
private int _from;
private int _to;
private String _uri;
ErrorCodeRange(int from, int to, String uri)
throws IllegalArgumentException
{
if (from > to)
throw new IllegalArgumentException("from>to");
_from = from;
_to = to;
_uri = uri;
}
boolean isInRange(int value)
{
return _from <= value && value <= _to;
}
String getUri()
{
return _uri;
}
@Override
public String toString()
{
return "from: " + _from + ",to: " + _to + ",uri: " + _uri;
}
}
}