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The core jetty server artifact.
//
// ========================================================================
// 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.server.handler;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.nio.BufferOverflowException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.stream.Collectors;
import org.eclipse.jetty.http.HttpException;
import org.eclipse.jetty.http.HttpField;
import org.eclipse.jetty.http.HttpFields;
import org.eclipse.jetty.http.HttpHeader;
import org.eclipse.jetty.http.HttpStatus;
import org.eclipse.jetty.http.MimeTypes.Type;
import org.eclipse.jetty.http.PreEncodedHttpField;
import org.eclipse.jetty.http.QuotedQualityCSV;
import org.eclipse.jetty.io.ByteBufferOutputStream;
import org.eclipse.jetty.io.Content;
import org.eclipse.jetty.io.Retainable;
import org.eclipse.jetty.io.RetainableByteBuffer;
import org.eclipse.jetty.server.Request;
import org.eclipse.jetty.server.Response;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.util.Attributes;
import org.eclipse.jetty.util.BufferUtil;
import org.eclipse.jetty.util.Callback;
import org.eclipse.jetty.util.StringUtil;
import org.eclipse.jetty.util.annotation.ManagedAttribute;
import org.eclipse.jetty.util.annotation.ManagedObject;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Handler for Error pages
* An ErrorHandler is registered with {@link Server#setErrorHandler(Request.Handler)}.
* It is called by the {@link Response#writeError(Request, Response, Callback, int, String)}
* to generate an error page.
*/
@ManagedObject
public class ErrorHandler implements Request.Handler
{
// TODO This classes API needs to be majorly refactored/cleanup in jetty-10
private static final Logger LOG = LoggerFactory.getLogger(ErrorHandler.class);
public static final String ERROR_STATUS = "org.eclipse.jetty.server.error_status";
public static final String ERROR_MESSAGE = "org.eclipse.jetty.server.error_message";
public static final String ERROR_EXCEPTION = "org.eclipse.jetty.server.error_exception";
public static final String ERROR_CONTEXT = "org.eclipse.jetty.server.error_context";
public static final Set ERROR_METHODS = Set.of("GET", "POST", "HEAD");
public static final HttpField ERROR_CACHE_CONTROL = new PreEncodedHttpField(HttpHeader.CACHE_CONTROL, "must-revalidate,no-cache,no-store");
boolean _showStacks = true;
boolean _showMessageInTitle = true;
HttpField _cacheControl = new PreEncodedHttpField(HttpHeader.CACHE_CONTROL, "must-revalidate,no-cache,no-store");
public ErrorHandler()
{
}
public boolean errorPageForMethod(String method)
{
return ERROR_METHODS.contains(method);
}
@Override
public boolean handle(Request request, Response response, Callback callback) throws Exception
{
if (LOG.isDebugEnabled())
LOG.debug("handle({}, {}, {})", request, response, callback);
if (_cacheControl != null)
response.getHeaders().put(_cacheControl);
int code = response.getStatus();
String message = (String)request.getAttribute(ERROR_MESSAGE);
Throwable cause = (Throwable)request.getAttribute(ERROR_EXCEPTION);
if (cause instanceof HttpException httpException)
{
code = httpException.getCode();
response.setStatus(code);
if (message == null)
message = httpException.getReason();
}
if (!errorPageForMethod(request.getMethod()) || HttpStatus.hasNoBody(code))
{
callback.succeeded();
}
else
{
if (message == null)
message = cause == null ? HttpStatus.getMessage(code) : cause.toString();
generateResponse(request, response, code, message, cause, callback);
}
return true;
}
protected void generateResponse(Request request, Response response, int code, String message, Throwable cause, Callback callback) throws IOException
{
List acceptable = request.getHeaders().getQualityCSV(HttpHeader.ACCEPT, QuotedQualityCSV.MOST_SPECIFIC_MIME_ORDERING);
if (acceptable.isEmpty())
{
if (request.getHeaders().contains(HttpHeader.ACCEPT))
{
callback.succeeded();
return;
}
acceptable = Collections.singletonList(Type.TEXT_HTML.asString());
}
List charsets = request.getHeaders().getQualityCSV(HttpHeader.ACCEPT_CHARSET).stream()
.map(s ->
{
try
{
if ("*".equals(s))
return StandardCharsets.UTF_8;
return Charset.forName(s);
}
catch (Throwable t)
{
return null;
}
})
.filter(Objects::nonNull)
.collect(Collectors.toList());
if (charsets.isEmpty())
{
charsets = List.of(StandardCharsets.ISO_8859_1, StandardCharsets.UTF_8);
if (request.getHeaders().contains(HttpHeader.ACCEPT_CHARSET))
{
callback.succeeded();
return;
}
}
for (String mimeType : acceptable)
{
if (generateAcceptableResponse(request, response, callback, mimeType, charsets, code, message, cause))
return;
}
callback.succeeded();
}
protected boolean generateAcceptableResponse(Request request, Response response, Callback callback, String contentType, List charsets, int code, String message, Throwable cause) throws IOException
{
Type type;
Charset charset;
switch (contentType)
{
case "text/html":
case "text/*":
case "*/*":
type = Type.TEXT_HTML;
charset = charsets.stream().findFirst().orElse(StandardCharsets.ISO_8859_1);
break;
case "text/json":
case "application/json":
if (charsets.contains(StandardCharsets.UTF_8))
charset = StandardCharsets.UTF_8;
else if (charsets.contains(StandardCharsets.ISO_8859_1))
charset = StandardCharsets.ISO_8859_1;
else
return false;
type = Type.TEXT_JSON.is(contentType) ? Type.TEXT_JSON : Type.APPLICATION_JSON;
break;
case "text/plain":
type = Type.TEXT_PLAIN;
charset = charsets.stream().findFirst().orElse(StandardCharsets.ISO_8859_1);
break;
default:
return false;
}
int bufferSize = request.getConnectionMetaData().getHttpConfiguration().getOutputBufferSize();
bufferSize = Math.min(8192, bufferSize); // TODO ?
RetainableByteBuffer buffer = request.getComponents().getByteBufferPool().acquire(bufferSize, false);
try
{
// write into the response aggregate buffer and flush it asynchronously.
// Looping to reduce size if buffer overflows
boolean showStacks = isShowStacks();
while (true)
{
try
{
buffer.clear();
ByteBufferOutputStream out = new ByteBufferOutputStream(buffer.getByteBuffer());
PrintWriter writer = new PrintWriter(new OutputStreamWriter(out, charset));
switch (type)
{
case TEXT_HTML -> writeErrorHtml(request, writer, charset, code, message, cause, showStacks);
case TEXT_JSON, APPLICATION_JSON -> writeErrorJson(request, writer, code, message, cause, showStacks);
case TEXT_PLAIN -> writeErrorPlain(request, writer, code, message, cause, showStacks);
default -> throw new IllegalStateException();
}
writer.flush();
break;
}
catch (BufferOverflowException e)
{
if (showStacks)
{
if (LOG.isDebugEnabled())
LOG.debug("Disable stacks for " + e.toString());
showStacks = false;
continue;
}
if (LOG.isDebugEnabled())
LOG.warn("Error page too large: >{} {} {} {}", bufferSize, code, message, request, e);
else
LOG.warn("Error page too large: >{} {} {} {}", bufferSize, code, message, request);
break;
}
}
if (!buffer.hasRemaining())
{
buffer.release();
callback.succeeded();
return true;
}
response.getHeaders().put(type.getContentTypeField(charset));
response.write(true, buffer.getByteBuffer(), new WriteErrorCallback(callback, buffer));
return true;
}
catch (Throwable x)
{
buffer.release();
throw x;
}
}
protected void writeErrorHtml(Request request, Writer writer, Charset charset, int code, String message, Throwable cause, boolean showStacks) throws IOException
{
if (message == null)
message = HttpStatus.getMessage(code);
writer.write("\n\n");
writeErrorHtmlMeta(request, writer, charset);
writeErrorHtmlHead(request, writer, code, message);
writer.write("\n\n");
writeErrorHtmlBody(request, writer, code, message, cause, showStacks);
writer.write("\n\n\n");
}
protected void writeErrorHtmlMeta(Request request, Writer writer, Charset charset) throws IOException
{
writer.write("\n");
}
protected void writeErrorHtmlHead(Request request, Writer writer, int code, String message) throws IOException
{
writer.write("Error ");
String status = Integer.toString(code);
writer.write(status);
if (isShowMessageInTitle() && message != null && !message.equals(status))
{
writer.write(' ');
writer.write(StringUtil.sanitizeXmlString(message));
}
writer.write(" \n");
}
protected void writeErrorHtmlBody(Request request, Writer writer, int code, String message, Throwable cause, boolean showStacks) throws IOException
{
String uri = request.getHttpURI().toString();
writeErrorHtmlMessage(request, writer, code, message, cause, uri);
if (showStacks)
writeErrorHtmlStacks(request, writer);
request.getConnectionMetaData().getHttpConfiguration()
.writePoweredBy(writer, "
", "
\n");
}
protected void writeErrorHtmlMessage(Request request, Writer writer, int code, String message, Throwable cause, String uri) throws IOException
{
writer.write("HTTP ERROR ");
String status = Integer.toString(code);
writer.write(status);
if (message != null && !message.equals(status))
{
writer.write(' ');
writer.write(StringUtil.sanitizeXmlString(message));
}
writer.write("
\n");
writer.write("\n");
htmlRow(writer, "URI", uri);
htmlRow(writer, "STATUS", status);
htmlRow(writer, "MESSAGE", message);
while (cause != null)
{
htmlRow(writer, "CAUSED BY", cause);
cause = cause.getCause();
}
writer.write("
\n");
}
private void htmlRow(Writer writer, String tag, Object value) throws IOException
{
writer.write("");
writer.write(tag);
writer.write(": ");
if (value == null)
writer.write("-");
else
writer.write(StringUtil.sanitizeXmlString(value.toString()));
writer.write(" json = new HashMap<>();
json.put("url", request.getHttpURI().toString());
json.put("status", Integer.toString(code));
json.put("message", message);
int c = 0;
while (cause != null)
{
json.put("cause" + c++, cause.toString());
cause = cause.getCause();
}
writer.append(json.entrySet().stream()
.map(e -> HttpField.NAME_VALUE_TOKENIZER.quote(e.getKey()) + ":" + HttpField.NAME_VALUE_TOKENIZER.quote(StringUtil.sanitizeXmlString((e.getValue()))))
.collect(Collectors.joining(",\n", "{\n", "\n}")));
}
protected void writeErrorHtmlStacks(Request request, Writer writer) throws IOException
{
Throwable th = (Throwable)request.getAttribute(ERROR_EXCEPTION);
if (th != null)
{
writer.write("Caused by:
");
// You have to pre-generate and then use #write(writer, String)
try (StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw))
{
th.printStackTrace(pw);
pw.flush();
write(writer, sw.getBuffer().toString()); // sanitize
}
writer.write("\n");
}
}
/**
* Bad Message Error body
* Generate an 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.Mutable fields)
{
if (reason == null)
reason = HttpStatus.getMessage(status);
if (HttpStatus.hasNoBody(status))
return BufferUtil.EMPTY_BUFFER;
fields.put(HttpHeader.CONTENT_TYPE, 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.
*/
@ManagedAttribute("The value of the Cache-Control response header")
public String getCacheControl()
{
return _cacheControl == null ? null : _cacheControl.getValue();
}
/**
* Set the cacheControl.
*
* @param cacheControl the cacheControl header to set on error responses.
*/
public void setCacheControl(String cacheControl)
{
_cacheControl = cacheControl == null ? null : new PreEncodedHttpField(HttpHeader.CACHE_CONTROL, cacheControl);
}
/**
* @return True if stack traces are shown in the error pages
*/
@ManagedAttribute("Whether the error page shows the stack trace")
public boolean isShowStacks()
{
return _showStacks;
}
/**
* @param showStacks True if stack traces are shown in the error pages
*/
public void setShowStacks(boolean showStacks)
{
_showStacks = showStacks;
}
@ManagedAttribute("Whether the error message is shown in the error page title")
public boolean isShowMessageInTitle()
{
return _showMessageInTitle;
}
/**
* Set if true, the error message appears in page title.
* @param showMessageInTitle if true, the error message appears in page title
*/
public void setShowMessageInTitle(boolean showMessageInTitle)
{
_showMessageInTitle = showMessageInTitle;
}
protected void write(Writer writer, String string) throws IOException
{
if (string == null)
return;
writer.write(StringUtil.sanitizeXmlString(string));
}
public static Request.Handler getErrorHandler(Server server, ContextHandler context)
{
Request.Handler errorHandler = null;
if (context != null)
errorHandler = context.getErrorHandler();
if (errorHandler == null && server != null)
errorHandler = server.getErrorHandler();
return errorHandler;
}
public static class ErrorRequest extends Request.AttributesWrapper
{
private static final Set ATTRIBUTES = Set.of(ERROR_MESSAGE, ERROR_EXCEPTION, ERROR_STATUS);
public ErrorRequest(Request request, int status, String message, Throwable cause)
{
super(request, new Attributes.Synthetic(request)
{
@Override
protected Object getSyntheticAttribute(String name)
{
return switch (name)
{
case ERROR_MESSAGE -> message;
case ERROR_EXCEPTION -> cause;
case ERROR_STATUS -> status;
default -> null;
};
}
@Override
protected Set getSyntheticNameSet()
{
return ATTRIBUTES;
}
});
}
@Override
public Content.Chunk read()
{
return Content.Chunk.EOF;
}
@Override
public void demand(Runnable demandCallback)
{
demandCallback.run();
}
@Override
public String toString()
{
return "%s@%x:%s".formatted(getClass().getSimpleName(), hashCode(), getWrapped());
}
}
/**
* The callback used by
* {@link ErrorHandler#generateAcceptableResponse(Request, Response, Callback, String, List, int, String, Throwable)}
* when calling {@link Response#write(boolean, ByteBuffer, Callback)} to wrap the passed in {@link Callback}
* so that the {@link RetainableByteBuffer} used can be released.
*/
private static class WriteErrorCallback extends Callback.Nested
{
private final Retainable _retainable;
public WriteErrorCallback(Callback callback, Retainable retainable)
{
super(callback);
_retainable = retainable;
}
@Override
public void completed()
{
_retainable.release();
}
}
}