Add idle timeout property for Reactor Netty

See gh-27371

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/ServerProperties.java

@@ -1300,6 +1300,12 @@ public class ServerProperties {
 		 */
 		private boolean validateHeaders = true;
 
+		/**
+		 * IdleTimeout for netty server .If an idletimeout is not specified, this
+		 * indicates no timeout(infinite).
+		 */
+		private Duration idleTimeout;
+
 		public Duration getConnectionTimeout() {
 			return this.connectionTimeout;
 		}
@@ -1348,6 +1354,14 @@ public class ServerProperties {
 			this.validateHeaders = validateHeaders;
 		}
 
+		public Duration getIdleTimeout() {
+			return this.idleTimeout;
+		}
+
+		public void setIdleTimeout(Duration idleTimeout) {
+			this.idleTimeout = idleTimeout;
+		}
+
 	}
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizer.java

@@ -60,6 +60,8 @@ public class NettyWebServerFactoryCustomizer
 		ServerProperties.Netty nettyProperties = this.serverProperties.getNetty();
 		propertyMapper.from(nettyProperties::getConnectionTimeout).whenNonNull()
 				.to((connectionTimeout) -> customizeConnectionTimeout(factory, connectionTimeout));
+		propertyMapper.from(nettyProperties::getIdleTimeout).whenNonNull()
+				.to((idleTimeout) -> customizeIdleTimeout(factory, idleTimeout));
 		customizeRequestDecoder(factory, propertyMapper);
 	}
 
@@ -98,4 +100,8 @@ public class NettyWebServerFactoryCustomizer
 		}));
 	}
 
+	private void customizeIdleTimeout(NettyReactiveWebServerFactory factory, Duration idleTimeout) {
+		factory.addServerCustomizers((httpServer) -> httpServer.idleTimeout(idleTimeout));
+	}
+
 }

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java

@@ -535,6 +535,12 @@ class ServerPropertiesTests {
 				.isEqualTo(HttpDecoderSpec.DEFAULT_INITIAL_BUFFER_SIZE);
 	}
 
+	@Test
+	void testCustomizeNettyIdleTimeout() {
+		bind("server.netty.idle-timeout", "10s");
+		assertThat(this.properties.getNetty().getIdleTimeout()).isEqualTo(Duration.ofSeconds(10));
+	}
+
 	private Connector getDefaultConnector() {
 		return new Connector(TomcatServletWebServerFactory.DEFAULT_PROTOCOL);
 	}

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/NettyWebServerFactoryCustomizerTests.java

@@ -104,12 +104,22 @@ class NettyWebServerFactoryCustomizerTests {
 
 	@Test
 	void setConnectionTimeout() {
-		setupConnectionTimeout(Duration.ofSeconds(1));
+		setServerProperties();
+		this.serverProperties.getNetty().setConnectionTimeout(Duration.ofSeconds(1));
 		NettyReactiveWebServerFactory factory = mock(NettyReactiveWebServerFactory.class);
 		this.customizer.customize(factory);
 		verifyConnectionTimeout(factory, 1000);
 	}
 
+	@Test
+	void setIdleTimeout() {
+		setServerProperties();
+		this.serverProperties.getNetty().setIdleTimeout(Duration.ofSeconds(1));
+		NettyReactiveWebServerFactory factory = mock(NettyReactiveWebServerFactory.class);
+		this.customizer.customize(factory);
+		verifyIdleTimeout(factory, Duration.ofSeconds(1));
+	}
+
 	@Test
 	void configureHttpRequestDecoder() {
 		ServerProperties.Netty nettyProperties = this.serverProperties.getNetty();
@@ -143,10 +153,21 @@ class NettyWebServerFactoryCustomizerTests {
 		assertThat(options.get(ChannelOption.CONNECT_TIMEOUT_MILLIS)).isEqualTo(expected);
 	}
 
-	private void setupConnectionTimeout(Duration connectionTimeout) {
+	private void verifyIdleTimeout(NettyReactiveWebServerFactory factory, Duration expected) {
+		if (expected == null) {
+			verify(factory, never()).addServerCustomizers(any(NettyServerCustomizer.class));
+			return;
+		}
+		verify(factory, times(2)).addServerCustomizers(this.customizerCaptor.capture());
+		NettyServerCustomizer serverCustomizer = this.customizerCaptor.getAllValues().get(0);
+		HttpServer httpServer = serverCustomizer.apply(HttpServer.create());
+		Duration idleTimeout = httpServer.configuration().idleTimeout();
+		assertThat(idleTimeout).isEqualTo(expected);
+	}
+
+	private void setServerProperties() {
 		this.serverProperties.setForwardHeadersStrategy(ForwardHeadersStrategy.NONE);
 		this.serverProperties.setMaxHttpHeaderSize(null);
-		this.serverProperties.getNetty().setConnectionTimeout(connectionTimeout);
 	}
 
 }