Use spring.session.timeout for Spring Session timeout

Fallback to server.servlet.session.timeout for backwards compatibility.

Fixes gh-12906

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/session/SessionProperties.java

@@ -17,13 +17,17 @@
 package org.springframework.boot.autoconfigure.session;
 
 import java.time.Duration;
+import java.time.temporal.ChronoUnit;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 
+import javax.annotation.PostConstruct;
+
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.convert.DurationUnit;
 import org.springframework.boot.web.servlet.DispatcherType;
 import org.springframework.boot.web.servlet.server.Session;
 import org.springframework.session.web.http.SessionRepositoryFilter;
@@ -45,17 +49,25 @@ public class SessionProperties {
 	private StoreType storeType;
 
 	/**
-	 * Session timeout.
+	 * Session timeout. If a duration suffix is not specified, seconds will be used.
 	 */
-	private final Duration timeout;
+	@DurationUnit(ChronoUnit.SECONDS)
+	private Duration timeout;
 
 	private Servlet servlet = new Servlet();
 
+	private final ServerProperties serverProperties;
+
 	public SessionProperties(ObjectProvider<ServerProperties> serverProperties) {
-		ServerProperties properties = serverProperties.getIfUnique();
-		Session session = (properties == null ? null
-				: properties.getServlet().getSession());
-		this.timeout = (session == null ? null : session.getTimeout());
+		this.serverProperties = serverProperties.getIfUnique();
+	}
+
+	@PostConstruct
+	public void checkSessionTimeout() {
+		if (this.timeout == null && this.serverProperties != null) {
+			Session session = this.serverProperties.getServlet().getSession();
+			this.timeout = (session == null ? null : session.getTimeout());
+		}
 	}
 
 	public StoreType getStoreType() {
@@ -83,6 +95,10 @@ public class SessionProperties {
 		this.servlet = servlet;
 	}
 
+	public void setTimeout(Duration timeout) {
+		this.timeout = timeout;
+	}
+
 	/**
 	 * Servlet-related properties.
 	 */

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/session/SessionAutoConfigurationTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.autoconfigure.session;
 
+import java.time.Duration;
 import java.util.Collections;
 import java.util.EnumSet;
 
@@ -23,9 +24,10 @@ import javax.servlet.DispatcherType;
 
 import org.junit.Test;
 
-import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.web.ServerProperties;
 import org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.boot.web.servlet.FilterRegistrationBean;
 import org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext;
@@ -98,15 +100,23 @@ public class SessionAutoConfigurationTests extends AbstractSessionAutoConfigurat
 	}
 
 	@Test
-	public void springSessionTimeoutIsNotAValidProperty() {
-		this.contextRunner.withUserConfiguration(SessionRepositoryConfiguration.class)
-				.withPropertyValues("spring.session.timeout=3000").run((context) -> {
-					assertThat(context).hasFailed();
-					assertThat(context).getFailure()
-							.isInstanceOf(BeanCreationException.class);
-					assertThat(context).getFailure()
-							.hasMessageContaining("Could not bind");
-				});
+	public void autoConfigWhenSpringSessionTimeoutIsSetShouldUseThat() {
+		this.contextRunner.withUserConfiguration(ServerPropertiesConfiguration.class,
+				SessionRepositoryConfiguration.class)
+				.withPropertyValues("server.servlet.session.timeout=1",
+						"spring.session.timeout=3").run((context) ->
+				assertThat(context.getBean(SessionProperties.class).getTimeout())
+						.isEqualTo(Duration.ofSeconds(3)));
+	}
+
+	@Test
+	public void autoConfigWhenSpringSessionTimeoutIsNotSetShouldUseServerSessionTimeout() {
+		this.contextRunner.withUserConfiguration(ServerPropertiesConfiguration.class,
+				SessionRepositoryConfiguration.class)
+				.withPropertyValues("server.servlet.session.timeout=3").run((context) -> {
+			assertThat(context.getBean(SessionProperties.class).getTimeout())
+					.isEqualTo(Duration.ofSeconds(3));
+		});
 	}
 
 	@SuppressWarnings("unchecked")
@@ -184,4 +194,9 @@ public class SessionAutoConfigurationTests extends AbstractSessionAutoConfigurat
 
 	}
 
+	@EnableConfigurationProperties(ServerProperties.class)
+	static class ServerPropertiesConfiguration {
+
+	}
+
 }

spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -445,6 +445,7 @@ content into your application. Rather, pick only the properties that you need.
 
 	# SPRING SESSION ({sc-spring-boot-autoconfigure}/session/SessionProperties.{sc-ext}[SessionProperties])
 	spring.session.store-type= # Session store type.
+	spring.session.timeout= # Session timeout. If a duration suffix is not specified, seconds will be used.
 	spring.session.servlet.filter-order=-2147483598 # Session repository filter order.
 	spring.session.servlet.filter-dispatcher-types=async,error,request # Session repository filter dispatcher types.
 

spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -6014,7 +6014,8 @@ the name of the table for the JDBC store, as shown in the following example:
     spring.session.jdbc.table-name=SESSIONS
 ----
 
-
+For setting the timeout of the session you can use the `spring.session.timeout` property.
+If that property is not set, the auto-configuration will fallback to the value of `server.servlet.session.timeout`.
 
 [[boot-features-jmx]]
 == Monitoring and Management over JMX