我正在使用httpclient 4.5.5作为响应,我希望获得高达1GB的大型文件。但看上去
CloseableHttpResponse response = httpClient.execute(httpGet); HttpEntity entity = response.getEntity();
这将返回整个响应,因此在内存中拥有整个响应并不好。有什么方法可以作为流得到响应吗?
发布于 2018-03-20 11:10:46
ApacheHTTP4.0版(以及)支持传入和传出HttpClient消息的完整内容流。使用HttpEntity访问下面的内容输入流
CloseableHttpClient client = HttpClients.createDefault();
HttpGet httpGet = new HttpGet("http://myhost/tons-of-stuff");
try (CloseableHttpResponse response1 = client.execute(httpGet)) {
final HttpEntity entity = response1.getEntity();
if (entity != null) {
try (InputStream inputStream = entity.getContent()) {
// do something useful with the stream
}
}
}发布于 2018-03-18 12:41:07
您需要Apache异步客户端。
HttpAsyncClient是Apache HttpClient的ASYNC版本。Apache在内存中构造整个响应,而使用HttpAsyncClient,您可以定义一个Handler (使用者)来处理接收数据时的响应。
https://hc.apache.org/httpcomponents-asyncclient-4.1.x/index.html下面是他们官方示例代码中的一个示例
package org.apache.http.examples.nio.client;
import java.io.IOException;
import java.nio.CharBuffer;
import java.util.concurrent.Future;
import org.apache.http.HttpResponse;
import org.apache.http.impl.nio.client.CloseableHttpAsyncClient;
import org.apache.http.impl.nio.client.HttpAsyncClients;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.client.methods.AsyncCharConsumer;
import org.apache.http.nio.client.methods.HttpAsyncMethods;
import org.apache.http.protocol.HttpContext;
/**
* This example demonstrates an asynchronous HTTP request / response exchange with
* a full content streaming.
*/
public class AsyncClientHttpExchangeStreaming {
public static void main(final String[] args) throws Exception {
CloseableHttpAsyncClient httpclient = HttpAsyncClients.createDefault();
try {
httpclient.start();
Future<Boolean> future = httpclient.execute(
HttpAsyncMethods.createGet("http://httpbin.org/"),
new MyResponseConsumer(), null);
Boolean result = future.get();
if (result != null && result.booleanValue()) {
System.out.println("Request successfully executed");
} else {
System.out.println("Request failed");
}
System.out.println("Shutting down");
} finally {
httpclient.close();
}
System.out.println("Done");
}
static class MyResponseConsumer extends AsyncCharConsumer<Boolean> {
@Override
protected void onResponseReceived(final HttpResponse response) {
}
@Override
protected void onCharReceived(final CharBuffer buf, final IOControl ioctrl) throws IOException {
while (buf.hasRemaining()) {
System.out.print(buf.get());
}
}
@Override
protected void releaseResources() {
}
@Override
protected Boolean buildResult(final HttpContext context) {
return Boolean.TRUE;
}
}
}发布于 2018-03-18 12:16:26
使用HttpURLConnection而不是httpClient。
final HttpURLConnection conn = (HttpURLConnection)url.openConnection();
final int bufferSize = 1024 * 1024;
conn.setChunkedStreamingMode(bufferSize);
final OutputStream out = conn.getOutputStream();https://stackoverflow.com/questions/49346948
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