8371471: HttpClient: Log HTTP/3 handshake failures if logging errors is enabled

src/java.net.http/share/classes/jdk/internal/net/http/common/Log.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -391,8 +391,7 @@ public static void logError(String s, Object... s1) {
 
     public static void logError(Throwable t) {
         if (errors()) {
-            String s = Utils.stackTrace(t);
-            logger.log(Level.INFO, "ERROR: " + s);
+            logger.log(Level.INFO, "ERROR: " + t, t);
         }
     }
 

src/java.net.http/share/classes/jdk/internal/net/http/quic/QuicConnectionImpl.java

@@ -591,6 +591,11 @@ public void failHandshakeCFs(final Throwable cause) {
             SSLHandshakeException sslHandshakeException = null;
             if (!handshakeCF.isDone()) {
                 sslHandshakeException = sslHandshakeException(cause);
+                if (Log.errors()) {
+                    Log.logError("%s QUIC handshake failed: %s"
+                            .formatted(logTag(), message(cause)));
+                    Log.logError(cause);
+                }
                 handshakeCF.completeExceptionally(sslHandshakeException);
             }
             if (!handshakeReachedPeerCF.isDone()) {
@@ -608,6 +613,12 @@ private SSLHandshakeException sslHandshakeException(final Throwable cause) {
             return new SSLHandshakeException("QUIC connection establishment failed", cause);
         }
 
+        private String message(Throwable cause) {
+            String message = cause.getMessage();
+            if (message != null && !message.isEmpty()) return message;
+            return cause.toString();
+        }
+
         /**
          * Marks the start of a handshake.
          * @throws IllegalStateException If handshake has already started

test/jdk/java/net/httpclient/http3/H3LogHandshakeErrors.java

@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.net.http.HttpResponse.BodyHandlers;
+import java.util.Arrays;
+import java.util.Optional;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.logging.Level;
+import java.util.logging.LogRecord;
+import java.util.logging.Logger;
+import java.util.logging.Handler;
+
+import javax.net.ssl.SSLContext;
+
+import jdk.httpclient.test.lib.common.HttpServerAdapters;
+import jdk.internal.net.http.quic.QuicConnectionImpl;
+import jdk.test.lib.net.SimpleSSLContext;
+import org.testng.Assert;
+import org.testng.annotations.AfterClass;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import static java.net.http.HttpClient.Builder.NO_PROXY;
+import static java.net.http.HttpClient.Version.HTTP_3;
+import static java.net.http.HttpOption.Http3DiscoveryMode.HTTP_3_URI_ONLY;
+import static org.testng.Assert.*;
+
+/*
+ * @test
+ * @bug 8371471
+ * @summary Verify that HTTP/3 handshake failures are logged if
+ *          logging errors is enabled
+ * @library /test/lib /test/jdk/java/net/httpclient/lib
+ * @build jdk.test.lib.net.SimpleSSLContext
+ *        jdk.httpclient.test.lib.common.HttpServerAdapters
+ * @run testng/othervm
+ *              -Djdk.httpclient.HttpClient.log=errors
+ *              H3LogHandshakeErrors
+ */
+// -Djava.security.debug=all
+public class H3LogHandshakeErrors implements HttpServerAdapters {
+
+    private SSLContext sslContext;
+    private HttpTestServer h3Server;
+    private String requestURI;
+
+    @BeforeClass
+    public void beforeClass() throws Exception {
+        sslContext = new SimpleSSLContext().get();
+        if (sslContext == null) {
+            throw new AssertionError("Unexpected null sslContext");
+        }
+        // create an H3 only server
+        h3Server = HttpTestServer.create(HTTP_3_URI_ONLY, sslContext);
+        h3Server.addHandler((exchange) -> exchange.sendResponseHeaders(200, 0), "/hello");
+        h3Server.start();
+        System.out.println("Server started at " + h3Server.getAddress());
+        requestURI = "https://" + h3Server.serverAuthority() + "/hello";
+    }
+
+    @AfterClass
+    public void afterClass() throws Exception {
+        if (h3Server != null) {
+            System.out.println("Stopping server " + h3Server.getAddress());
+            h3Server.stop();
+        }
+    }
+
+    static String format(LogRecord record) {
+        String thrown = Optional.ofNullable(record.getThrown())
+                .map(t -> ": " + t).orElse("");
+        return "\n  \"%s: %s %s: %s%s\"".formatted(
+                record.getLevel(),
+                record.getSourceClassName(),
+                record.getSourceMethodName(),
+                record.getMessage(),
+                thrown);
+    }
+
+    /**
+     * Issues a GET HTTP3 requests and verifies that the
+     * expected exception is logged.
+     */
+    @Test
+    public void testErrorLogging() throws Exception {
+        // jdk.httpclient.HttpClient.log=errors must be enabled
+        // for this test
+        String logging = System.getProperty("jdk.httpclient.HttpClient.log", "");
+        var categories = Arrays.asList(logging.split(","));
+        assertTrue(categories.contains("errors"),
+                "'errors' not found in " + categories);
+
+        // create a client that doesn't have the server's
+        // certificate
+        final HttpClient client = newClientBuilderForH3()
+                .proxy(NO_PROXY)
+                .build();
+        final URI reqURI = new URI(requestURI);
+        final HttpRequest.Builder reqBuilder = HttpRequest.newBuilder(reqURI)
+                .version(HTTP_3);
+        Logger serverLogger = Logger.getLogger("jdk.httpclient.HttpClient");
+
+        CopyOnWriteArrayList<LogRecord> records = new CopyOnWriteArrayList<>();
+        Handler handler = new Handler() {
+            @Override
+            public void publish(LogRecord record) {
+                record.getSourceClassName();
+                records.add(record);
+            }
+            @Override public void flush() {}
+            @Override public void close() {
+            }
+        };
+        serverLogger.addHandler(handler);
+
+        try {
+            final HttpRequest req1 = reqBuilder.copy().GET().build();
+            System.out.println("Issuing request: " + req1);
+            final HttpResponse<Void> resp1 = client.send(req1, BodyHandlers.discarding());
+            Assert.assertEquals(resp1.statusCode(), 200, "unexpected response code for GET request");
+        } catch (IOException io) {
+            System.out.println("Got expected exception: " + io);
+        } finally {
+            LogRecord expected = null;
+            // this is a bit fragile and may need to be updated if the
+            // place where we log the exception from changes.
+            String expectedClassName = QuicConnectionImpl.class.getName()
+                    + "$HandshakeFlow";
+            for (var record : records) {
+                if (record.getLevel() != Level.INFO) continue;
+                if (!record.getMessage().contains("ERROR:")) continue;
+                if (record.getMessage().contains("client peer")) continue;
+                var expectedThrown = record.getThrown();
+                if (expectedThrown == null) continue;
+                if (!record.getSourceClassName().equals(expectedClassName)) continue;
+                if (expectedThrown.getMessage().contains("client peer")) continue;
+                expected = record;
+                break;
+            }
+            assertNotNull(expected, "No throwable for "
+                    + expectedClassName + " found in "
+                    + records.stream().map(H3LogHandshakeErrors::format).toList()
+                    + "\n ");
+            System.out.printf("Found expected exception: %s%n\t logged at: %s %s%n",
+                    expected.getThrown(),
+                    expected.getSourceClassName(),
+                    expected.getSourceMethodName());
+        }
+    }
+}