org.eclipse.jetty.ee8.servlet.ErrorPageErrorHandler Maven / Gradle / Ivy
//
// ========================================================================
// Copyright (c) 1995 Mort Bay Consulting Pty Ltd and others.
//
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License v. 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
// 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.ee8.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.ee8.nested.ContextHandler;
import org.eclipse.jetty.ee8.nested.Dispatcher;
import org.eclipse.jetty.ee8.nested.ErrorHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 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 static final String GLOBAL_ERROR_PAGE = "org.eclipse.jetty.server.error_page.global";
private static final Logger LOG = LoggerFactory.getLogger(ErrorPageErrorHandler.class);
private enum PageLookupTechnique {
THROWABLE, STATUS_CODE, GLOBAL
}
// code or exception to URL
private final Map _errorPages = new HashMap<>();
// list of ErrorCode by range
private final List _errorPageList = new ArrayList<>();
protected ServletContext _servletContext;
private boolean _unwrapServletException = true;
/**
* @return True if ServletException is unwrapped for {@link Dispatcher#ERROR_EXCEPTION}
*/
public boolean isUnwrapServletException() {
return _unwrapServletException;
}
/**
* @param unwrapServletException True if ServletException should be unwrapped for {@link Dispatcher#ERROR_EXCEPTION}
*/
public void setUnwrapServletException(boolean unwrapServletException) {
_unwrapServletException = unwrapServletException;
}
@Override
public String getErrorPage(HttpServletRequest request) {
String errorPage = null;
PageLookupTechnique pageSource = null;
Class matchedThrowable = null;
Throwable error = (Throwable) request.getAttribute(Dispatcher.ERROR_EXCEPTION);
Throwable cause = error;
// Walk the cause hierarchy
while (errorPage == null && cause != null) {
pageSource = PageLookupTechnique.THROWABLE;
Class exClass = cause.getClass();
errorPage = _errorPages.get(exClass.getName());
// walk the inheritance hierarchy
while (errorPage == null) {
exClass = exClass.getSuperclass();
if (exClass == null)
break;
errorPage = _errorPages.get(exClass.getName());
}
if (errorPage != null)
matchedThrowable = exClass;
cause = (cause instanceof ServletException) ? ((ServletException) cause).getRootCause() : null;
}
if (error instanceof ServletException && _unwrapServletException) {
Throwable unwrapped = unwrapServletException(error, matchedThrowable);
if (unwrapped != null) {
request.setAttribute(Dispatcher.ERROR_EXCEPTION, unwrapped);
request.setAttribute(Dispatcher.ERROR_EXCEPTION_TYPE, unwrapped.getClass());
}
}
Integer errorStatusCode = null;
if (errorPage == null) {
pageSource = PageLookupTechnique.STATUS_CODE;
// look for an exact code match
errorStatusCode = (Integer) request.getAttribute(Dispatcher.ERROR_STATUS_CODE);
if (errorStatusCode != null) {
errorPage = _errorPages.get(Integer.toString(errorStatusCode));
// if still not found
if (errorPage == null) {
// look for an error code range match.
for (ErrorCodeRange errCode : _errorPageList) {
if (errCode.isInRange(errorStatusCode)) {
errorPage = errCode.getUri();
break;
}
}
}
}
}
// Try servlet 3.x global error page.
if (errorPage == null) {
pageSource = PageLookupTechnique.GLOBAL;
errorPage = _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(errorPage);
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(), cause);
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;
default:
throw new IllegalStateException(pageSource.toString());
}
}
return errorPage;
}
/**
* @param t the initial exception
* @param matchedThrowable the class we found matching the error page (can be null)
* @return the first non {@link ServletException} from root cause chain
*/
private Throwable unwrapServletException(Throwable t, Class matchedThrowable) {
if (matchedThrowable != null && t.getClass() == matchedThrowable)
return t;
if (t instanceof ServletException && t.getCause() != null) {
return unwrapServletException(t.getCause(), matchedThrowable);
}
return t;
}
public Map getErrorPages() {
return _errorPages;
}
/**
* Set a map of Exception class names or error codes as a string to URI string.
* @param errorPages a map of Exception class names or error codes as a string to URI string
*/
public void setErrorPages(Map 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 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 final int _from;
private final int _to;
private final 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;
}
}
}
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