Change persistence model structure

- Fix wrong acquire logic in DefaultStatemachineService.
- Overhaul StateMachineRuntimePersister
- Change StateMachineRuntimePersister to extend
  StateMachinePersist which should work better on
  a bean level. Also add generic type T to it and
  config where needed.
- Relates to #432
- Relates to #427

spring-statemachine-data/jpa/src/main/java/org/springframework/statemachine/data/jpa/JpaPersistingStateMachineInterceptor.java

@@ -16,7 +16,6 @@
 package org.springframework.statemachine.data.jpa;
 
 import org.springframework.statemachine.StateMachineContext;
-import org.springframework.statemachine.StateMachinePersist;
 import org.springframework.statemachine.persist.AbstractPersistingStateMachineInterceptor;
 import org.springframework.statemachine.persist.StateMachineRuntimePersister;
 import org.springframework.statemachine.support.StateMachineInterceptor;
@@ -29,9 +28,10 @@ import org.springframework.util.Assert;
  *
  * @param <S> the type of state
  * @param <E> the type of event
+ * @param <T> the type of persister context object
  */
-public class JpaPersistingStateMachineInterceptor<S, E> extends AbstractPersistingStateMachineInterceptor<S, E>
-		implements StateMachinePersist<S, E, Object>, StateMachineRuntimePersister<S, E> {
+public class JpaPersistingStateMachineInterceptor<S, E, T> extends AbstractPersistingStateMachineInterceptor<S, E, T>
+		implements StateMachineRuntimePersister<S, E, T> {
 
 	private final JpaRepositoryStateMachinePersist<S, E> persist;
 
@@ -61,7 +61,7 @@ public class JpaPersistingStateMachineInterceptor<S, E> extends AbstractPersisti
 	}
 
 	@Override
-	public void write(StateMachineContext<S, E> context, Object contextObj) throws Exception {
+	public void write(StateMachineContext<S, E> context, T contextObj) throws Exception {
 		persist.write(context, contextObj);
 	}
 

spring-statemachine-data/jpa/src/test/java/org/springframework/statemachine/data/jpa/JpaRepositoryTests.java

@@ -363,7 +363,7 @@ public class JpaRepositoryTests extends AbstractRepositoryTests {
 		}
 
 		@Bean
-		public StateMachineRuntimePersister<String, String> stateMachineRuntimePersister() {
+		public StateMachineRuntimePersister<String, String, String> stateMachineRuntimePersister() {
 			return new JpaPersistingStateMachineInterceptor<>(jpaStateMachineRepository);
 		}
 	}
@@ -408,7 +408,7 @@ public class JpaRepositoryTests extends AbstractRepositoryTests {
 		}
 
 		@Bean
-		public StateMachineRuntimePersister<PersistTestStates, PersistTestEvents> stateMachineRuntimePersister() {
+		public StateMachineRuntimePersister<PersistTestStates, PersistTestEvents, String> stateMachineRuntimePersister() {
 			return new JpaPersistingStateMachineInterceptor<>(jpaStateMachineRepository);
 		}
 	}