| /* |
| * ==================================================================== |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| */ |
| package org.apache.http.nio.client.methods; |
| |
| import java.io.File; |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.io.RandomAccessFile; |
| import java.nio.channels.FileChannel; |
| |
| import org.apache.http.Header; |
| import org.apache.http.HttpEntity; |
| import org.apache.http.HttpResponse; |
| import org.apache.http.entity.ContentType; |
| import org.apache.http.entity.FileEntity; |
| import org.apache.http.nio.ContentDecoder; |
| import org.apache.http.nio.ContentDecoderChannel; |
| import org.apache.http.nio.FileContentDecoder; |
| import org.apache.http.nio.IOControl; |
| import org.apache.http.nio.protocol.AbstractAsyncResponseConsumer; |
| import org.apache.http.protocol.HttpContext; |
| import org.apache.http.util.Asserts; |
| |
| /** |
| * {@link org.apache.http.nio.protocol.HttpAsyncResponseConsumer} implementation that |
| * streams content entity enclosed in an HTTP response directly into a file |
| * without an intermediate in-memory buffer. |
| * <p> |
| * This consumer can be useful for file downloads. |
| * |
| * @since 4.0 |
| */ |
| public abstract class ZeroCopyConsumer<T> extends AbstractAsyncResponseConsumer<T> { |
| |
| private final File file; |
| private final RandomAccessFile accessfile; |
| |
| private HttpResponse response; |
| private ContentType contentType; |
| private Header contentEncoding; |
| private FileChannel fileChannel; |
| private long idx = -1; |
| |
| public ZeroCopyConsumer(final File file) throws FileNotFoundException { |
| super(); |
| if (file == null) { |
| throw new IllegalArgumentException("File may nor be null"); |
| } |
| this.file = file; |
| this.accessfile = new RandomAccessFile(this.file, "rw"); |
| } |
| |
| @Override |
| protected void onResponseReceived(final HttpResponse response) { |
| this.response = response; |
| } |
| |
| @Override |
| protected void onEntityEnclosed( |
| final HttpEntity entity, final ContentType contentType) throws IOException { |
| this.contentType = contentType; |
| this.contentEncoding = entity.getContentEncoding(); |
| this.fileChannel = this.accessfile.getChannel(); |
| this.idx = 0; |
| } |
| |
| @Override |
| protected void onContentReceived( |
| final ContentDecoder decoder, final IOControl ioctrl) throws IOException { |
| Asserts.notNull(this.fileChannel, "File channel"); |
| final long transferred; |
| if (decoder instanceof FileContentDecoder) { |
| transferred = ((FileContentDecoder)decoder).transfer( |
| this.fileChannel, this.idx, Integer.MAX_VALUE); |
| } else { |
| transferred = this.fileChannel.transferFrom( |
| new ContentDecoderChannel(decoder), this.idx, Integer.MAX_VALUE); |
| } |
| if (transferred > 0) { |
| this.idx += transferred; |
| } |
| if (decoder.isCompleted()) { |
| this.fileChannel.close(); |
| } |
| } |
| |
| /** |
| * Invoked to process received file. |
| * |
| * @param response original response head. |
| * @param file file containing response content. |
| * @param contentType the cotnent type. |
| * @return result of the response processing |
| */ |
| protected abstract T process( |
| HttpResponse response, File file, ContentType contentType) throws Exception; |
| |
| @Override |
| protected T buildResult(final HttpContext context) throws Exception { |
| final FileEntity entity = new FileEntity(this.file, this.contentType); |
| entity.setContentEncoding(this.contentEncoding); |
| this.response.setEntity(entity); |
| return process(this.response, this.file, this.contentType); |
| } |
| |
| @Override |
| protected void releaseResources() { |
| try { |
| this.accessfile.close(); |
| } catch (final IOException ignore) { |
| } |
| } |
| |
| } |