如何调用从JAVA客户端返回空响应的HEAD请求？

我试图调用一个API，它返回100作为响应代码和空响应

import org.apache.http.client.methods.HttpHead;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

import java.net.URI;

public class SampleController {

    public static void main(String[] args) throws Exception {

        try {
            String urlStr = "http://localhost:8080/headrequest";
            HttpHead request = new HttpHead(new URI(urlStr));
            request.addHeader("Expect", "100-continue");

            CloseableHttpClient client = HttpClients.createDefault();
            client.execute(request);
        } catch (Exception e) {
            System.out.println("Exception: " + e.getMessage());
            throw e;
        }
    }
}

以下是错误：

INFO: I/O exception (org.apache.http.NoHttpResponseException) caught when processing request to {}->http://localhost:8080: The target server failed to respond
Aug 19, 2020 3:36:26 PM org.apache.http.impl.execchain.RetryExec execute
INFO: Retrying request to {}->http://localhost:8080
Aug 19, 2020 3:36:26 PM org.apache.http.impl.execchain.RetryExec execute
INFO: I/O exception (org.apache.http.NoHttpResponseException) caught when processing request to {}->http://localhost:8080: The target server failed to respond
Aug 19, 2020 3:36:26 PM org.apache.http.impl.execchain.RetryExec execute
INFO: Retrying request to {}->http://localhost:8080
Aug 19, 2020 3:36:26 PM org.apache.http.impl.execchain.RetryExec execute
INFO: I/O exception (org.apache.http.NoHttpResponseException) caught when processing request to {}->http://localhost:8080: The target server failed to respond
Aug 19, 2020 3:36:26 PM org.apache.http.impl.execchain.RetryExec execute
INFO: Retrying request to {}->http://localhost:8080
Exception in thread "main" org.apache.http.NoHttpResponseException: localhost:8080 failed to respond
Exception: localhost:8080 failed to respond
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:141)
    at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:56)
    at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:259)
    at org.apache.http.impl.DefaultBHttpClientConnection.receiveResponseHeader(DefaultBHttpClientConnection.java:163)
    at org.apache.http.impl.conn.CPoolProxy.receiveResponseHeader(CPoolProxy.java:157)
    at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:273)
    at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:125)
    at org.apache.http.impl.execchain.MainClientExec.execute(MainClientExec.java:272)
    at org.apache.http.impl.execchain.ProtocolExec.execute(ProtocolExec.java:186)
    at org.apache.http.impl.execchain.RetryExec.execute(RetryExec.java:89)
    at org.apache.http.impl.execchain.RedirectExec.execute(RedirectExec.java:110)
    at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:185)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:83)
    at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:108)
    at com.application.controller.SampleController.main(SampleController.java:20)

但是从服务器访问日志。我可以确认API已经执行，服务器返回了100响应代码

“头部/头枕HTTP/1.1”100

因此，从上面的错误中，我了解到apaches HttpClinet没有配置为在服务器发送响应代码100并且仍然希望服务器发送响应时终止连接

import org.apache.http.client.methods.HttpHead;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

import java.net.URI;

public class SampleController {

    public static void main(String[] args) throws Exception {

        try {
            String urlStr = "http://localhost:8080/headrequest";
            HttpHead request = new HttpHead(new URI(urlStr));
            request.addHeader("Expect", "100-continue");

            CloseableHttpClient client = HttpClients.createDefault();
            client.execute(request);
        } catch (Exception e) {
            System.out.println("Exception: " + e.getMessage());
            throw e;
        }
    }
}

我这里的问题是，是否有java libs在收到100个请求后处理HEAD请求的终止

我确实尝试过谷歌搜索，但没有找到任何解决方案：(

编辑1:我尝试了

HttpURLConnection

private static void testing() throws Exception {
        HttpURLConnection urlConn = null;

        try {
            String urlStr = "http://localhost:8080/headrequest";

            URL url = new URL(urlStr);
            urlConn = (HttpURLConnection) url.openConnection();
            urlConn.setRequestMethod("HEAD");

            
            urlConn.setRequestProperty("Expect", "100-continue");

            if (urlConn.getResponseCode() != 100) {
                System.out.println("Miss match in the response: " + urlConn.getResponseCode());
            }

        } catch (Exception e) {
            System.out.println("Exception: " + e.getMessage());
            throw e;
        }
    }

以下是错误响应：

Exception: Unexpected end of file from server
Exception in thread "main" java.net.SocketException: Unexpected end of file from server
    at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:851)
    at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:877)
    at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:877)
    at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:678)
    at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:848)
    at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:877)
    at sun.net.www.http.HttpClient.parseHTTPHeader(HttpClient.java:877)
    at sun.net.www.http.HttpClient.parseHTTP(HttpClient.java:678)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1593)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1498)
    at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
    at com.application.controller.SampleController.testing(SampleController.java:44)
    at com.application.controller.SampleController.main(SampleController.java:28)

说

客户机不得在请求中生成100个连续期望值 它不包括消息正文

因此，它的客户端可能希望在收到100个响应后发送消息体，在连接关闭时抛出异常

如果不强制使用apacheclient，下面的简单代码将仅读取带有100个状态代码的响应行并关闭连接

import java.io.*；
导入java.net。*；
类请求程序
{
公共静态void main（字符串参数[]）
{
插座；
缓冲剂；
缓冲写入器bw；
字符串a；
字符串响应；
试一试{
s=新套接字（“本地主机”，8080）；
br=新的BufferedReader（新的InputStreamReader（新的BufferedInputStream（s.getInputStream（））））；
bw=新的BufferedWriter（新的OutputStreamWriter（新的BufferedOutputStream（s.getOutputStream（））））；
写（“头枕/头枕HTTP/1.1”）；
换行符（）；
换行符（）；
bw.flush（）；
答复=”；
a=br.readLine（）；
系统输出打印项次（a）；
s、 close（）；
}
捕获（例外e）
{
系统输出打印ln（e）；
}
}
}

是的，这是可以理解的。但是，在java中，如何检查服务器是否返回100。顺便说一句，感谢您的回复。@Finnismissing我已经更新了答案，以包含从服务器读取状态响应的代码。