Java tutorial
/* * Copyright 2013-2018 the original author or authors. * * 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 org.cloudfoundry.reactor.util; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.handler.codec.http.DefaultHttpHeaders; import io.netty.handler.codec.http.HttpHeaders; import io.netty.util.AsciiString; import reactor.core.Exceptions; import reactor.core.publisher.Mono; import reactor.ipc.netty.NettyOutbound; import reactor.ipc.netty.http.client.HttpClientRequest; import java.io.IOException; import java.nio.file.Files; import java.nio.file.Path; import java.util.ArrayList; import java.util.Comparator; import java.util.List; import java.util.Map; import java.util.Random; import java.util.function.Consumer; import java.util.stream.Collectors; import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_DISPOSITION; import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_LENGTH; import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE; import static io.netty.handler.codec.http.HttpHeaderValues.MULTIPART_FORM_DATA; public final class MultipartHttpClientRequest { private static final byte[] BOUNDARY_CHARS = new byte[] { '-', '_', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' }; private static final AsciiString BOUNDARY_PREAMBLE = MULTIPART_FORM_DATA.concat("; boundary="); private static final AsciiString CRLF = new AsciiString("\r\n"); private static final AsciiString DOUBLE_DASH = new AsciiString("--"); private static final Random RND = new Random(); private final ObjectMapper objectMapper; private final List<Consumer<PartHttpClientRequest>> partConsumers = new ArrayList<>(); private final HttpClientRequest request; public MultipartHttpClientRequest(ObjectMapper objectMapper, HttpClientRequest request) { this.objectMapper = objectMapper; this.request = request; } public MultipartHttpClientRequest addPart(Consumer<PartHttpClientRequest> partConsumer) { this.partConsumers.add(partConsumer); return this; } public Mono<Void> done() { AsciiString boundary = generateMultipartBoundary(); AsciiString delimiter = getDelimiter(boundary); AsciiString closeDelimiter = getCloseDelimiter(boundary); List<PartHttpClientRequest> parts = this.partConsumers.stream().map(partConsumer -> { PartHttpClientRequest part = new PartHttpClientRequest(this.objectMapper); partConsumer.accept(part); return part; }).collect(Collectors.toList()); Long contentLength = parts.stream().mapToLong(part -> delimiter.length() + CRLF.length() + part.getLength()) .sum() + closeDelimiter.length(); NettyOutbound intermediateRequest = this.request.chunkedTransfer(false) .header(CONTENT_TYPE, BOUNDARY_PREAMBLE.concat(boundary)) .header(CONTENT_LENGTH, String.valueOf(contentLength)); for (PartHttpClientRequest part : parts) { intermediateRequest = intermediateRequest.sendObject(Unpooled.wrappedBuffer(delimiter.toByteArray())); intermediateRequest = intermediateRequest.sendObject(Unpooled.wrappedBuffer(CRLF.toByteArray())); intermediateRequest = intermediateRequest.sendObject(part.renderedHeaders); intermediateRequest = part.sendPayload(intermediateRequest); } intermediateRequest = intermediateRequest.sendObject(Unpooled.wrappedBuffer(closeDelimiter.toByteArray())); return intermediateRequest.then(); } private static AsciiString generateMultipartBoundary() { byte[] boundary = new byte[RND.nextInt(11) + 30]; for (int i = 0; i < boundary.length; i++) { boundary[i] = BOUNDARY_CHARS[RND.nextInt(BOUNDARY_CHARS.length)]; } return new AsciiString(boundary); } private static AsciiString getCloseDelimiter(AsciiString boundary) { return CRLF.concat(DOUBLE_DASH).concat(boundary).concat(DOUBLE_DASH); } private static AsciiString getDelimiter(AsciiString boundary) { return CRLF.concat(DOUBLE_DASH).concat(boundary); } public static final class PartHttpClientRequest { private static final AsciiString HEADER_DELIMITER = new AsciiString(": "); private final HttpHeaders headers = new DefaultHttpHeaders(true); private final ObjectMapper objectMapper; private Path file; private byte[] payload; private ByteBuf renderedHeaders; private PartHttpClientRequest(ObjectMapper objectMapper) { this.objectMapper = objectMapper; } public void send(Object source) { try { byte[] bytes = this.objectMapper.writeValueAsBytes(source); this.headers.set(CONTENT_LENGTH, bytes.length); this.renderedHeaders = renderHeaders(); this.payload = bytes; } catch (JsonProcessingException e) { throw Exceptions.propagate(e); } } public void sendFile(Path file) { try { this.headers.set(CONTENT_LENGTH, Files.size(file)); this.renderedHeaders = renderHeaders(); this.file = file; } catch (IOException e) { throw Exceptions.propagate(e); } } public PartHttpClientRequest setContentDispositionFormData(String name) { return setContentDispositionFormData(name, null); } public PartHttpClientRequest setContentDispositionFormData(String name, String filename) { AsciiString s = new AsciiString("form-data; name=\"").concat(name).concat("\""); if (filename != null) { s = s.concat("; filename=\"").concat(filename).concat("\""); } this.headers.set(CONTENT_DISPOSITION, s); return this; } public PartHttpClientRequest setHeader(CharSequence name, CharSequence value) { this.headers.set(name, value); return this; } private long getLength() { return this.renderedHeaders.readableBytes() + getPayloadLength(); } private long getPayloadLength() { if (this.file != null) { try { return Files.size(this.file); } catch (IOException e) { throw Exceptions.propagate(e); } } else if (this.payload != null) { return this.payload.length; } else { return 0; } } private ByteBuf renderHeaders() { AsciiString s = this.headers.entries().stream().sorted(Comparator.comparing(Map.Entry::getKey)) .map(entry -> new AsciiString(entry.getKey()).concat(HEADER_DELIMITER).concat(entry.getValue()) .concat(CRLF)) .reduce(AsciiString::concat).orElse(AsciiString.EMPTY_STRING).concat(CRLF); return Unpooled.wrappedBuffer(s.toByteArray()); } private NettyOutbound sendPayload(NettyOutbound request) { if (this.file != null) { return request.sendFile(this.file); } else if (this.payload != null) { return request.sendByteArray(Mono.just(this.payload)); } else { return request; } } } }