Add ExpiringSession setLastAccessedTime

Previously SessionRepository had to update the lastAccessTime when it was
loaded. This prevented inspecting the last access time. For example,
listing all the sessions for a specific user. Furthermore, it is
unintuitive that a read operation would update attributes on the domain
model.

This change introduces ExpiringSession setLastAccessedTime to allow setting
the expiration on the interface. This means that the SessionRepositoryFilter
can update the last accessed time.

Fixes gh-272

spring-session/src/test/java/org/springframework/session/MapSessionTests.java

@@ -94,6 +94,10 @@ public class MapSessionTests {
 			return "id";
 		}
 
+		public void setLastAccessedTime(long lastAccessedTime) {
+			throw new UnsupportedOperationException();
+		}
+
 		public long getLastAccessedTime() {
 			return 0;
 		}

spring-session/src/test/java/org/springframework/session/data/redis/RedisOperationsSessionRepositoryTests.java

@@ -319,7 +319,7 @@ public class RedisOperationsSessionRepositoryTests {
 		assertThat(session.getAttribute(attrName)).isEqualTo(expected.getAttribute(attrName));
 		assertThat(session.getCreationTime()).isEqualTo(expected.getCreationTime());
 		assertThat(session.getMaxInactiveIntervalInSeconds()).isEqualTo(expected.getMaxInactiveIntervalInSeconds());
-		assertThat(session.getLastAccessedTime()).isGreaterThanOrEqualTo(now);
+		assertThat(session.getLastAccessedTime()).isEqualTo(expected.getLastAccessedTime());
 
 	}
 

spring-session/src/test/java/org/springframework/session/web/http/SessionRepositoryFilterTests.java

@@ -126,7 +126,7 @@ public class SessionRepositoryFilterTests {
 			}
 		});
 
-		Thread.sleep(10L);
+		Thread.sleep(1L);
 		nextRequest();
 
 		doFilter(new DoInFilter() {