A demo of a request made by httpclient blocking forever, despite timeouts being set.

InfiniteBlockRequest.java

import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URI;
import java.net.URISyntaxException;

public class InfiniteBlockingRequest {

    public static void main(String... args) throws IOException, URISyntaxException {
        new Thread(() -> {
            try {
                ServerSocket serverSocket = new ServerSocket(41567);
                Socket clientSocket = serverSocket.accept();
                PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
                while(true){
                    Thread.sleep(10000);
                    out.write("\r\n");
                    out.flush();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }).start();

        CloseableHttpClient httpClient =
                HttpClients.custom()
                .setDefaultRequestConfig(RequestConfig.custom()
                        .setSocketTimeout(15000)
                        .setConnectionRequestTimeout(500)
                        .setConnectTimeout(500).build())
                .build();
        httpClient.execute(new HttpPost(new URI("http://localhost:41567")));
        System.out.println("Never gets here.");
    }


}