Java tutorial
/* * Copyright 2002-2017 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 * * https://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.springframework.http.client; import java.io.IOException; import java.net.HttpURLConnection; import java.net.Proxy; import java.net.URI; import java.net.URL; import java.net.URLConnection; import org.springframework.core.task.AsyncListenableTaskExecutor; import org.springframework.http.HttpMethod; import org.springframework.lang.Nullable; import org.springframework.util.Assert; /** * {@link ClientHttpRequestFactory} implementation that uses standard JDK facilities. * * @author Arjen Poutsma * @author Juergen Hoeller * @since 3.0 * @see java.net.HttpURLConnection * @see HttpComponentsClientHttpRequestFactory */ @SuppressWarnings("deprecation") public class SimpleClientHttpRequestFactory implements ClientHttpRequestFactory, AsyncClientHttpRequestFactory { private static final int DEFAULT_CHUNK_SIZE = 4096; @Nullable private Proxy proxy; private boolean bufferRequestBody = true; private int chunkSize = DEFAULT_CHUNK_SIZE; private int connectTimeout = -1; private int readTimeout = -1; private boolean outputStreaming = true; @Nullable private AsyncListenableTaskExecutor taskExecutor; /** * Set the {@link Proxy} to use for this request factory. */ public void setProxy(Proxy proxy) { this.proxy = proxy; } /** * Indicate whether this request factory should buffer the * {@linkplain ClientHttpRequest#getBody() request body} internally. * <p>Default is {@code true}. When sending large amounts of data via POST or PUT, * it is recommended to change this property to {@code false}, so as not to run * out of memory. This will result in a {@link ClientHttpRequest} that either * streams directly to the underlying {@link HttpURLConnection} (if the * {@link org.springframework.http.HttpHeaders#getContentLength() Content-Length} * is known in advance), or that will use "Chunked transfer encoding" * (if the {@code Content-Length} is not known in advance). * @see #setChunkSize(int) * @see HttpURLConnection#setFixedLengthStreamingMode(int) */ public void setBufferRequestBody(boolean bufferRequestBody) { this.bufferRequestBody = bufferRequestBody; } /** * Set the number of bytes to write in each chunk when not buffering request * bodies locally. * <p>Note that this parameter is only used when * {@link #setBufferRequestBody(boolean) bufferRequestBody} is set to {@code false}, * and the {@link org.springframework.http.HttpHeaders#getContentLength() Content-Length} * is not known in advance. * @see #setBufferRequestBody(boolean) */ public void setChunkSize(int chunkSize) { this.chunkSize = chunkSize; } /** * Set the underlying URLConnection's connect timeout (in milliseconds). * A timeout value of 0 specifies an infinite timeout. * <p>Default is the system's default timeout. * @see URLConnection#setConnectTimeout(int) */ public void setConnectTimeout(int connectTimeout) { this.connectTimeout = connectTimeout; } /** * Set the underlying URLConnection's read timeout (in milliseconds). * A timeout value of 0 specifies an infinite timeout. * <p>Default is the system's default timeout. * @see URLConnection#setReadTimeout(int) */ public void setReadTimeout(int readTimeout) { this.readTimeout = readTimeout; } /** * Set if the underlying URLConnection can be set to 'output streaming' mode. * Default is {@code true}. * <p>When output streaming is enabled, authentication and redirection cannot be handled automatically. * If output streaming is disabled, the {@link HttpURLConnection#setFixedLengthStreamingMode} and * {@link HttpURLConnection#setChunkedStreamingMode} methods of the underlying connection will never * be called. * @param outputStreaming if output streaming is enabled */ public void setOutputStreaming(boolean outputStreaming) { this.outputStreaming = outputStreaming; } /** * Set the task executor for this request factory. Setting this property is required * for {@linkplain #createAsyncRequest(URI, HttpMethod) creating asynchronous requests}. * @param taskExecutor the task executor */ public void setTaskExecutor(AsyncListenableTaskExecutor taskExecutor) { this.taskExecutor = taskExecutor; } @Override public ClientHttpRequest createRequest(URI uri, HttpMethod httpMethod) throws IOException { HttpURLConnection connection = openConnection(uri.toURL(), this.proxy); prepareConnection(connection, httpMethod.name()); if (this.bufferRequestBody) { return new SimpleBufferingClientHttpRequest(connection, this.outputStreaming); } else { return new SimpleStreamingClientHttpRequest(connection, this.chunkSize, this.outputStreaming); } } /** * {@inheritDoc} * <p>Setting the {@link #setTaskExecutor taskExecutor} property is required before calling this method. */ @Override public AsyncClientHttpRequest createAsyncRequest(URI uri, HttpMethod httpMethod) throws IOException { Assert.state(this.taskExecutor != null, "Asynchronous execution requires TaskExecutor to be set"); HttpURLConnection connection = openConnection(uri.toURL(), this.proxy); prepareConnection(connection, httpMethod.name()); if (this.bufferRequestBody) { return new SimpleBufferingAsyncClientHttpRequest(connection, this.outputStreaming, this.taskExecutor); } else { return new SimpleStreamingAsyncClientHttpRequest(connection, this.chunkSize, this.outputStreaming, this.taskExecutor); } } /** * Opens and returns a connection to the given URL. * <p>The default implementation uses the given {@linkplain #setProxy(java.net.Proxy) proxy} - * if any - to open a connection. * @param url the URL to open a connection to * @param proxy the proxy to use, may be {@code null} * @return the opened connection * @throws IOException in case of I/O errors */ protected HttpURLConnection openConnection(URL url, @Nullable Proxy proxy) throws IOException { URLConnection urlConnection = (proxy != null ? url.openConnection(proxy) : url.openConnection()); if (!HttpURLConnection.class.isInstance(urlConnection)) { throw new IllegalStateException( "HttpURLConnection required for [" + url + "] but got: " + urlConnection); } return (HttpURLConnection) urlConnection; } /** * Template method for preparing the given {@link HttpURLConnection}. * <p>The default implementation prepares the connection for input and output, and sets the HTTP method. * @param connection the connection to prepare * @param httpMethod the HTTP request method ({@code GET}, {@code POST}, etc.) * @throws IOException in case of I/O errors */ protected void prepareConnection(HttpURLConnection connection, String httpMethod) throws IOException { if (this.connectTimeout >= 0) { connection.setConnectTimeout(this.connectTimeout); } if (this.readTimeout >= 0) { connection.setReadTimeout(this.readTimeout); } connection.setDoInput(true); if ("GET".equals(httpMethod)) { connection.setInstanceFollowRedirects(true); } else { connection.setInstanceFollowRedirects(false); } if ("POST".equals(httpMethod) || "PUT".equals(httpMethod) || "PATCH".equals(httpMethod) || "DELETE".equals(httpMethod)) { connection.setDoOutput(true); } else { connection.setDoOutput(false); } connection.setRequestMethod(httpMethod); } }