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 * 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
 *
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 *  distributed under the License is distributed on an "AS IS" BASIS,
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 *  See the License for the specific language governing permissions and
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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.

This handler does not server up and response codes by default, you must configure the response codes it responds to.

Author:Stuart Douglas
/** * 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.
/** * 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")); } } 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); } } }