Make message durability configurable

src/main/java/com/rabbitmq/client/amqp/Message.java

@@ -591,6 +591,19 @@ public interface Message {
    */
   byte[] body();
 
+  /**
+   * Mark the message as durable or not.
+   *
+   * <p>Messages are durable by default, use <code>false</code> to make them explicitly non-durable.
+   *
+   * <p>Durability depends also on the queue messages end up in (e.g. quorum queues and streams
+   * always store messages durably).
+   *
+   * @param durable true for a durable message, false for a non-durable message
+   * @return the message
+   */
+  Message durable(boolean durable);
+
   /**
    * Whether the message is durable.
    *

src/main/java/com/rabbitmq/client/amqp/impl/AmqpMessage.java

@@ -35,6 +35,8 @@ final class AmqpMessage implements Message {
 
   private final org.apache.qpid.protonj2.client.Message<byte[]> delegate;
 
+  private boolean durableIsSet = false;
+
   AmqpMessage() {
     this(org.apache.qpid.protonj2.client.Message.create(EMPTY_BODY));
   }
@@ -455,6 +457,14 @@ public byte[] body() {
   }
 
   // header section
+
+  @Override
+  public Message durable(boolean durable) {
+    this.durableIsSet = true;
+    callOnDelegate(m -> m.durable(durable));
+    return this;
+  }
+
   @Override
   public boolean durable() {
     return returnFromDelegate(org.apache.qpid.protonj2.client.Message::durable);
@@ -535,6 +545,13 @@ public MessageAddressBuilder replyToAddress() {
     return new DefaultMessageAddressBuilder(this, DefaultMessageAddressBuilder.REPLY_TO_CALLBACK);
   }
 
+  AmqpMessage enforceDurability() throws ClientException {
+    if (!this.durableIsSet) {
+      this.delegate.durable(true);
+    }
+    return this;
+  }
+
   private static class DefaultMessageAddressBuilder
       extends DefaultAddressBuilder<MessageAddressBuilder> implements MessageAddressBuilder {
 

src/main/java/com/rabbitmq/client/amqp/impl/AmqpPublisher.java

@@ -86,9 +86,7 @@ final class AmqpPublisher extends ResourceBase implements Publisher {
     this.publishCall =
         msg -> {
           try {
-            org.apache.qpid.protonj2.client.Message<?> nativeMessage =
-                ((AmqpMessage) msg).nativeMessage();
-            return this.sender.send(nativeMessage.durable(true));
+            return this.doSend((AmqpMessage) msg);
           } catch (ClientIllegalStateException e) {
             // the link is closed
             LOGGER.debug("Error while publishing: '{}'. Closing publisher.", e.getMessage());
@@ -154,6 +152,11 @@ private Status mapDeliveryState(DeliveryState in) {
     }
   }
 
+  private Tracker doSend(AmqpMessage msg) throws ClientException {
+    msg.enforceDurability();
+    return this.sender.send(msg.nativeMessage());
+  }
+
   private static MetricsCollector.PublishDisposition mapToPublishDisposition(Status status) {
     if (status == Status.ACCEPTED) {
       return MetricsCollector.PublishDisposition.ACCEPTED;

src/test/java/com/rabbitmq/client/amqp/impl/AmqpMessageTest.java

@@ -25,13 +25,32 @@ public class AmqpMessageTest {
 
   @Test
   void toShouldBePathEncoded() {
-    assertThat(new AmqpMessage().toAddress().exchange("foo bar").message().to())
+    assertThat(msg().toAddress().exchange("foo bar").message().to())
         .isEqualTo("/exchanges/foo%20bar");
   }
 
   @Test
   void replyToShouldBePathEncoded() {
-    assertThat(new AmqpMessage().replyToAddress().exchange("foo bar").message().replyTo())
+    assertThat(msg().replyToAddress().exchange("foo bar").message().replyTo())
         .isEqualTo("/exchanges/foo%20bar");
   }
+
+  @Test
+  void shouldBeNonDurableOnlyIfExplicitlySet() throws Exception {
+    AmqpMessage msg = msg();
+    // durable by default
+    assertThat(msg.enforceDurability().nativeMessage().durable()).isTrue();
+    // non-durable explicitly set
+    msg = msg();
+    msg.durable(false);
+    assertThat(msg.enforceDurability().nativeMessage().durable()).isFalse();
+    // durable explicitly set
+    msg = msg();
+    msg.durable(true);
+    assertThat(msg.enforceDurability().nativeMessage().durable()).isTrue();
+  }
+
+  private static AmqpMessage msg() {
+    return new AmqpMessage();
+  }
 }

src/test/java/com/rabbitmq/client/amqp/impl/AmqpTest.java

@@ -23,6 +23,7 @@
 import static com.rabbitmq.client.amqp.Management.QueueType.STREAM;
 import static com.rabbitmq.client.amqp.impl.Assertions.assertThat;
 import static com.rabbitmq.client.amqp.impl.TestConditions.BrokerVersion.RABBITMQ_4_0_3;
+import static com.rabbitmq.client.amqp.impl.TestConditions.BrokerVersion.RABBITMQ_4_2_0;
 import static com.rabbitmq.client.amqp.impl.TestUtils.*;
 import static com.rabbitmq.client.amqp.impl.Utils.threadFactory;
 import static java.nio.charset.StandardCharsets.*;
@@ -36,6 +37,7 @@
 
 import com.rabbitmq.client.amqp.AmqpException;
 import com.rabbitmq.client.amqp.Connection;
+import com.rabbitmq.client.amqp.ConsumerBuilder;
 import com.rabbitmq.client.amqp.Environment;
 import com.rabbitmq.client.amqp.Management;
 import com.rabbitmq.client.amqp.Message;
@@ -55,6 +57,7 @@
 import org.junit.jupiter.api.*;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
+import org.junit.jupiter.params.provider.EnumSource;
 import org.junit.jupiter.params.provider.ValueSource;
 
 @AmqpTestInfrastructure
@@ -906,4 +909,76 @@ void messageAnnotationsSupportListMapArray() {
     ints = (int[]) m.annotation("x-arrayInt");
     org.assertj.core.api.Assertions.assertThat(ints).containsExactly(4, 5, 6);
   }
+
+  @ParameterizedTest
+  @CsvSource({
+    "CLASSIC,true",
+    "CLASSIC,false",
+    "QUORUM,true",
+    "QUORUM,false",
+    "STREAM,true",
+    "STREAM,false"
+  })
+  @BrokerVersionAtLeast(RABBITMQ_4_2_0)
+  void explicitDurabilityShouldBeEnforced(Management.QueueType type, boolean durable) {
+    try {
+      connection.management().queue(this.name).type(type).declare();
+      Publisher p = connection.publisherBuilder().queue(this.name).build();
+      p.publish(p.message().durable(durable), ctx -> {});
+
+      Sync consumeSync = sync();
+      AtomicReference<Message> messageRef = new AtomicReference<>();
+      ConsumerBuilder builder =
+          connection
+              .consumerBuilder()
+              .queue(this.name)
+              .messageHandler(
+                  (context, message) -> {
+                    messageRef.set(message);
+                    context.accept();
+                    consumeSync.down();
+                  });
+      if (type == STREAM) {
+        builder.stream().offset(ConsumerBuilder.StreamOffsetSpecification.FIRST);
+      }
+      builder.build();
+      assertThat(consumeSync).completes();
+      Message message = messageRef.get();
+      assertThat(message).isDurable(durable);
+    } finally {
+      connection.management().queueDelete(this.name);
+    }
+  }
+
+  @ParameterizedTest
+  @EnumSource(Management.QueueType.class)
+  void durableByDefault(Management.QueueType type) {
+    try {
+      connection.management().queue(this.name).type(type).declare();
+      Publisher p = connection.publisherBuilder().queue(this.name).build();
+      p.publish(p.message(), ctx -> {});
+
+      Sync consumeSync = sync();
+      AtomicReference<Message> messageRef = new AtomicReference<>();
+      ConsumerBuilder builder =
+          connection
+              .consumerBuilder()
+              .queue(this.name)
+              .messageHandler(
+                  (context, message) -> {
+                    messageRef.set(message);
+                    context.accept();
+                    consumeSync.down();
+                  });
+      if (type == STREAM) {
+        builder.stream().offset(ConsumerBuilder.StreamOffsetSpecification.FIRST);
+      }
+      builder.build();
+      assertThat(consumeSync).completes();
+      Message message = messageRef.get();
+      assertThat(message).isDurable(true);
+    } finally {
+      connection.management().queueDelete(this.name);
+    }
+  }
 }

src/test/java/com/rabbitmq/client/amqp/impl/Assertions.java

@@ -359,6 +359,13 @@ private MessageAssert hasField(String fieldLabel, Object value, Object expected)
           .isEqualTo(expected);
       return this;
     }
+
+    void isDurable(boolean durable) {
+      isNotNull();
+      if (actual.durable() != durable) {
+        fail("Message durable flag should be %s but is %s", durable, actual.durable());
+      }
+    }
   }
 
   static class ConnectionAssert extends AbstractObjectAssert<ConnectionAssert, AmqpConnection> {

src/test/java/com/rabbitmq/client/amqp/impl/TestConditions.java

@@ -35,7 +35,8 @@ private TestConditions() {}
 
   public enum BrokerVersion {
     RABBITMQ_4_0_3("4.0.3"),
-    RABBITMQ_4_1_0("4.1.0");
+    RABBITMQ_4_1_0("4.1.0"),
+    RABBITMQ_4_2_0("4.2.0");
 
     final String value;