From 547c249ca80220b8a546278255e31e852691e57a Mon Sep 17 00:00:00 2001
From: Markus Malkusch <markus@malkusch.de>
Date: Fri, 3 Nov 2023 13:54:04 +0100
Subject: [PATCH] Workaround JDK http timeout bug

---
 pom.xml                                       |  7 +-
 .../malkusch/km200/HttpTimeoutWorkaround.java | 77 +++++++++++++++++++
 src/main/java/de/malkusch/km200/KM200.java    | 16 ++--
 3 files changed, 90 insertions(+), 10 deletions(-)
 create mode 100644 src/main/java/de/malkusch/km200/HttpTimeoutWorkaround.java

diff --git a/pom.xml b/pom.xml
index 2ebf664..f3314ec 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1,4 +1,6 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>de.malkusch.km200</groupId>
 	<artifactId>km200</artifactId>
@@ -13,7 +15,8 @@
 	<url>https://github.com/malkusch/${project.artifactId}</url>
 	<scm>
 		<connection>scm:git:git://github.com/malkusch/${project.artifactId}.git</connection>
-		<developerConnection>scm:git:git@github.com:malkusch/${project.artifactId}.git</developerConnection>
+		<developerConnection>
+			scm:git:git@github.com:malkusch/${project.artifactId}.git</developerConnection>
 	</scm>
 	<properties>
 		<github.repository>malkusch/km200</github.repository>
diff --git a/src/main/java/de/malkusch/km200/HttpTimeoutWorkaround.java b/src/main/java/de/malkusch/km200/HttpTimeoutWorkaround.java
new file mode 100644
index 0000000..e503b1f
--- /dev/null
+++ b/src/main/java/de/malkusch/km200/HttpTimeoutWorkaround.java
@@ -0,0 +1,77 @@
+package de.malkusch.km200;
+
+import static java.net.http.HttpClient.newBuilder;
+import static java.net.http.HttpClient.Redirect.ALWAYS;
+import static java.util.Optional.ofNullable;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+import java.io.IOException;
+import java.net.CookieManager;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.net.http.HttpResponse.BodyHandler;
+import java.net.http.HttpTimeoutException;
+import java.time.Duration;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+final class HttpTimeoutWorkaround implements AutoCloseable {
+
+    private final Duration timeout;
+    private final HttpClient client;
+    private final ScheduledExecutorService executor;
+
+    HttpTimeoutWorkaround(Duration timeout) {
+        this.client = newBuilder() //
+                .connectTimeout(timeout) //
+                .cookieHandler(new CookieManager()) //
+                .followRedirects(ALWAYS) //
+                .build();
+
+        this.timeout = timeout.plusSeconds(1);
+
+        executor = Executors.newSingleThreadScheduledExecutor(r -> {
+            var thread = new Thread(r, "KM200");
+            thread.setUncaughtExceptionHandler((t, e) -> {
+                e.printStackTrace();
+            });
+            thread.setDaemon(true);
+            return thread;
+        });
+    }
+
+    public <T> HttpResponse<T> send(HttpRequest request, BodyHandler<T> bodyHandler)
+            throws IOException, InterruptedException {
+
+        try {
+            return executor //
+                    .submit(() -> client.send(request, bodyHandler)) //
+                    .get(timeout.toMillis(), MILLISECONDS);
+
+        } catch (TimeoutException e) {
+            throw new HttpTimeoutException("KM200 timed out (HttpClient timed out)");
+
+        } catch (ExecutionException e) {
+            if (e.getCause() instanceof HttpTimeoutException timeoutException) {
+                throw timeoutException;
+            }
+            throw new IOException("KM200 failed", ofNullable(e.getCause()).orElse(e));
+        }
+    }
+
+    @Override
+    public void close() throws Exception {
+        executor.shutdown();
+        if (executor.awaitTermination(timeout.toMillis(), TimeUnit.MILLISECONDS)) {
+            return;
+        }
+        executor.shutdownNow();
+        if (!executor.awaitTermination(timeout.toMillis(), TimeUnit.MILLISECONDS)) {
+            throw new IOException("Closing KM200 failed");
+        }
+    }
+}
diff --git a/src/main/java/de/malkusch/km200/KM200.java b/src/main/java/de/malkusch/km200/KM200.java
index 314cd76..7c45445 100644
--- a/src/main/java/de/malkusch/km200/KM200.java
+++ b/src/main/java/de/malkusch/km200/KM200.java
@@ -1,14 +1,10 @@
 package de.malkusch.km200;
 
-import static java.net.http.HttpClient.newBuilder;
-import static java.net.http.HttpClient.Redirect.ALWAYS;
 import static java.util.Objects.requireNonNull;
 
 import java.io.IOException;
 import java.math.BigDecimal;
-import java.net.CookieManager;
 import java.net.URI;
-import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpRequest.BodyPublishers;
 import java.net.http.HttpResponse;
@@ -35,12 +31,12 @@
  * use it concurrently. Chances are that your KM200 gateway itself is not thread
  * safe.
  */
-public final class KM200 {
+public final class KM200 implements AutoCloseable {
 
     private final KM200Device device;
     private final KM200Comm comm;
     private final ObjectMapper mapper = new ObjectMapper();
-    private final HttpClient http;
+    private final HttpTimeoutWorkaround http;
     private final Duration timeout;
     private final String uri;
     private final FailsafeExecutor<HttpResponse<byte[]>> retry;
@@ -115,8 +111,7 @@ public KM200(String uri, Duration timeout, String gatewayPassword, String privat
         this.comm = new KM200Comm();
         this.timeout = timeout;
         this.uri = uri.replaceAll("/*$", "");
-        this.http = newBuilder().connectTimeout(timeout).cookieHandler(new CookieManager()).followRedirects(ALWAYS)
-                .build();
+        this.http = new HttpTimeoutWorkaround(timeout);
 
         retry = Failsafe.with( //
                 RetryPolicy.<HttpResponse<byte[]>> builder() //
@@ -283,4 +278,9 @@ private static void assertNotBlank(String var, String message) {
             throw new IllegalArgumentException(message);
         }
     }
+
+    @Override
+    public void close() throws Exception {
+        http.close();
+    }
 }