FileErrorPageHandler.java
/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.undertow.server.handlers.error;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
import io.undertow.util.MimeMappings;
import org.jboss.logging.Logger;
import org.xnio.IoUtils;
import org.xnio.channels.Channels;
import org.xnio.channels.StreamSinkChannel;
import io.undertow.Handlers;
import io.undertow.UndertowLogger;
import io.undertow.server.DefaultResponseListener;
import io.undertow.server.ExchangeCompletionListener;
import io.undertow.server.HandlerWrapper;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.ResponseCodeHandler;
import io.undertow.server.handlers.builder.HandlerBuilder;
import io.undertow.util.Headers;
/**
* Handler that serves up a file from disk to serve as an error page.
* <p>
* This handler does not server up and response codes by default, you must configure
* the response codes it responds to.
*
* @author Stuart Douglas
*/
public class FileErrorPageHandler implements HttpHandler {
private static final Logger log = Logger.getLogger("io.undertow.server.error.file");
private volatile HttpHandler next = ResponseCodeHandler.HANDLE_404;
/**
* The response codes that this handler will handle. If this is empty then this handler will have no effect.
*/
private volatile Set<Integer> responseCodes;
private volatile Path file;
private final MimeMappings mimeMappings;
@Deprecated
public FileErrorPageHandler(final File file, final Integer... responseCodes) {
this(file.toPath(), responseCodes);
}
public FileErrorPageHandler(final Path file, final Integer... responseCodes) {
this.file = file;
this.responseCodes = new HashSet<>(Arrays.asList(responseCodes));
this.mimeMappings = MimeMappings.DEFAULT;
}
@Deprecated
public FileErrorPageHandler(HttpHandler next, final File file, final Integer... responseCodes) {
this(next, file.toPath(), responseCodes);
}
public FileErrorPageHandler(HttpHandler next, final Path file, final Integer... responseCodes) {
this(next, file, MimeMappings.DEFAULT, responseCodes);
}
public FileErrorPageHandler(HttpHandler next, final Path file, MimeMappings mimeMappings, final Integer... responseCodes) {
this.next = next;
this.file = file;
this.responseCodes = new HashSet<>(Arrays.asList(responseCodes));
this.mimeMappings = mimeMappings;
}
@Override
public void handleRequest(final HttpServerExchange exchange) throws Exception {
exchange.addDefaultResponseListener(new DefaultResponseListener() {
@Override
public boolean handleDefaultResponse(final HttpServerExchange exchange) {
Set<Integer> codes = responseCodes;
if (!exchange.isResponseStarted() && codes.contains(exchange.getStatusCode())) {
serveFile(exchange);
return true;
}
return false;
}
});
next.handleRequest(exchange);
}
private void serveFile(final HttpServerExchange exchange) {
String fileName = file.toString();
int index = fileName.lastIndexOf(".");
if(index > 0) {
String contentType = mimeMappings.getMimeType(fileName.substring(index + 1));
if(contentType != null) {
exchange.getResponseHeaders().put(Headers.CONTENT_TYPE, contentType);
}
}
exchange.dispatch(new Runnable() {
@Override
public void run() {
final FileChannel fileChannel;
try {
try {
fileChannel = FileChannel.open(file, StandardOpenOption.READ);
} catch (FileNotFoundException e) {
UndertowLogger.REQUEST_IO_LOGGER.ioException(e);
exchange.endExchange();
return;
}
} catch (IOException e) {
UndertowLogger.REQUEST_IO_LOGGER.ioException(e);
exchange.endExchange();
return;
}
long size;
try {
size = Files.size(file);
} catch (IOException e) {
throw new RuntimeException(e);
}
exchange.getResponseHeaders().put(Headers.CONTENT_LENGTH, size);
final StreamSinkChannel response = exchange.getResponseChannel();
exchange.addExchangeCompleteListener(new ExchangeCompletionListener() {
@Override
public void exchangeEvent(HttpServerExchange exchange, NextListener nextListener) {
IoUtils.safeClose(fileChannel);
nextListener.proceed();
}
});
try {
log.tracef("Serving file %s (blocking)", fileChannel);
Channels.transferBlocking(response, fileChannel, 0, Files.size(file));
log.tracef("Finished serving %s, shutting down (blocking)", fileChannel);
response.shutdownWrites();
log.tracef("Finished serving %s, flushing (blocking)", fileChannel);
Channels.flushBlocking(response);
log.tracef("Finished serving %s (complete)", fileChannel);
exchange.endExchange();
} catch (IOException ignored) {
log.tracef("Failed to serve %s: %s", fileChannel, ignored);
exchange.endExchange();
IoUtils.safeClose(response);
} finally {
IoUtils.safeClose(fileChannel);
}
}
});
}
public HttpHandler getNext() {
return next;
}
public FileErrorPageHandler setNext(final HttpHandler next) {
Handlers.handlerNotNull(next);
this.next = next;
return this;
}
public Set<Integer> getResponseCodes() {
return Collections.unmodifiableSet(responseCodes);
}
public FileErrorPageHandler setResponseCodes(final Set<Integer> responseCodes) {
if (responseCodes == null) {
this.responseCodes = Collections.emptySet();
} else {
this.responseCodes = new HashSet<>(responseCodes);
}
return this;
}
public FileErrorPageHandler setResponseCodes(final Integer... responseCodes) {
this.responseCodes = new HashSet<>(Arrays.asList(responseCodes));
return this;
}
public Path getFile() {
return file;
}
public FileErrorPageHandler setFile(final Path file) {
this.file = file;
return this;
}
@Override
public String toString() {
return "response-codes( file='" + file.toString() + "', response-codes={ " + responseCodes.stream().map(s -> s.toString()).collect(Collectors.joining(", ")) + " } )";
}
public static class Builder implements HandlerBuilder {
@Override
public String name() {
return "error-file";
}
@Override
public Map<String, Class<?>> parameters() {
Map<String, Class<?>> params = new HashMap<>();
params.put("file", String.class);
params.put("response-codes", Integer[].class);
return params;
}
@Override
public Set<String> requiredParameters() {
return new HashSet<>(Arrays.asList(new String[]{"file", "response-codes"}));
}
@Override
public String defaultParameter() {
return null;
}
@Override
public HandlerWrapper build(Map<String, Object> config) {
return new Wrapper((String)config.get("file"), (Integer[]) config.get("response-codes"));
}
@Override
public int priority() {
return 0;
}
}
private static class Wrapper implements HandlerWrapper {
private final String file;
private final Integer[] responseCodes;
private Wrapper(String file, Integer[] responseCodes) {
this.file = file;
this.responseCodes = responseCodes;
}
@Override
public HttpHandler wrap(HttpHandler handler) {
return new FileErrorPageHandler(handler, Paths.get(file), responseCodes);
}
}
}