Proxy

Figure 1. Kafdrop Topic Viewer In the ever-expanding world of data streaming and event-driven architecture, Apache Kafka has emerged as a cornerstone for reliable and scalable data processing. However, managing and monitoring Kafka clusters can often present its own set of challenges. This is where Kafdrop, a web-based Kafka consumer group and topic viewer, comes to the rescue. With its intuitive interface and insightful visualizations, Kafdrop offers developers and operators an efficient way to gain valuable insights into Kafka clusters. ...

Sometimes this is useful for the diagnosis of configuration and network problems of ones Java application. This is our single-class HTTP client example without the need for external dependencies: HttpTest.java import javax.net.ssl.KeyManagerFactory; import javax.net.ssl.SSLContext; import javax.net.ssl.TrustManagerFactory; import java.io.FileInputStream; import java.io.IOException; import java.net.InetSocketAddress; import java.net.ProxySelector; import java.net.URI; import java.net.URISyntaxException; import java.net.http.HttpClient; import java.net.http.HttpRequest; import java.net.http.HttpRequest.BodyPublishers; import java.net.http.HttpResponse; import java.net.http.HttpResponse.BodyHandlers; import java.security.KeyManagementException; import java.security.KeyStore; import java.security.KeyStoreException; import java.security.NoSuchAlgorithmException; import java.security.UnrecoverableKeyException; import java.security.cert.CertificateException; import java.time.Duration; import java.time.temporal.ChronoUnit; public class HttpTest { public static void main(String[] args) throws URISyntaxException, NoSuchAlgorithmException, KeyManagementException, KeyStoreException, UnrecoverableKeyException, IOException, CertificateException { String bodyPayload = """ ourpayload, json, xml, ... """; String keyStorePath = "/opt/keystore.jks"; String keyStorePassword = "ABCDEFG"; String proxyHost = "ourproxy.proxy"; String uriString = "https://some-service/api"; int proxyPort = 8080; int timeoutInSeconds = 60; KeyStore keyStore = KeyStore.getInstance("JKS"); keyStore.load(new FileInputStream(keyStorePath), keyStorePassword.toCharArray()); KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("PKIX"); keyManagerFactory.init(keyStore, null); TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance("PKIX"); // using same keystore for both trustManagerFactory.init(keyStore); SSLContext sslContext = SSLContext.getInstance("TLS"); sslContext.init(keyManagerFactory.getKeyManagers(), trustManagerFactory.getTrustManagers(), null); HttpClient client = HttpClient.newBuilder() .proxy( ProxySelector.of(new InetSocketAddress(proxyHost, proxyPort))) .sslContext(sslContext) .build(); URI uri = new URI(uriString); HttpRequest request = HttpRequest.newBuilder(uri) .POST(BodyPublishers.ofString(bodyPayload)) .timeout(Duration.of(timeoutInSeconds, ChronoUnit.SECONDS)) .build(); System.out.printf("Sending POST request to %s, timeout: %ds%n", uri, timeoutInSeconds); try { HttpResponse response = client.send(request, BodyHandlers.ofString()); System.out.println("Response received..."); System.out.printf("\tResponse-Status: %d%n", response.statusCode()); System.out.printf("\tResponse-Body: %s%n", response.body()); System.out.println("-------------------------------------%n"); } catch (IOException e) { System.err.printf("IOException caught: %s%n", e.getMessage()); e.printStackTrace(System.err); } catch (InterruptedException e) { System.err.printf("IOException caught: %s%n", e.getMessage()); e.printStackTrace(System.err); } } } ...