Convert session timeout to minutes for Tomcat

Convert any session timeout values from seconds to minutes when
configuring Tomcat.

Fixes gh-1422

Author: philwebb

spring-boot/src/main/java/org/springframework/boot/context/embedded/tomcat/TomcatEmbeddedServletContainerFactory.java

@@ -25,6 +25,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.concurrent.TimeUnit;
 
 import javax.servlet.ServletContainerInitializer;
 import javax.servlet.ServletContext;
@@ -261,7 +262,12 @@ protected void configureContext(Context context,
 		for (MimeMappings.Mapping mapping : getMimeMappings()) {
 			context.addMimeMapping(mapping.getExtension(), mapping.getMimeType());
 		}
-		context.setSessionTimeout(getSessionTimeout());
+		long timeout = getSessionTimeout();
+		if (timeout > 0) {
+			// Tomcat timeouts are in minutes
+			timeout = Math.max(TimeUnit.SECONDS.toMinutes(timeout), 1L);
+		}
+		context.setSessionTimeout((int) timeout);
 		for (TomcatContextCustomizer customizer : this.tomcatContextCustomizers) {
 			customizer.customize(context);
 		}

spring-boot/src/test/java/org/springframework/boot/context/embedded/tomcat/TomcatEmbeddedServletContainerFactoryTests.java

@@ -155,14 +155,21 @@ public void addNullAdditionalConnectorThrows() {
 	public void sessionTimeout() throws Exception {
 		TomcatEmbeddedServletContainerFactory factory = getFactory();
 		factory.setSessionTimeout(10);
-		assertTimeout(factory, 10);
+		assertTimeout(factory, 1);
 	}
 
 	@Test
 	public void sessionTimeoutInMins() throws Exception {
 		TomcatEmbeddedServletContainerFactory factory = getFactory();
 		factory.setSessionTimeout(1, TimeUnit.MINUTES);
-		assertTimeout(factory, 60);
+		assertTimeout(factory, 1);
+	}
+
+	@Test
+	public void noSessionTimeout() throws Exception {
+		TomcatEmbeddedServletContainerFactory factory = getFactory();
+		factory.setSessionTimeout(0);
+		assertTimeout(factory, -1);
 	}
 
 	@Test