Add initial infra for config repository

- Initial infra for config abstraction with
  Spring Data Repositories via RepositoryStateMachineModelFactory.
- Initial jpa impl.
- Initial jpa sample atop of H2 DB.
- Relates to #250

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryState.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.data;
+
+/**
+ * Generic interface representing state entity.
+ *
+ * @author Janne Valkealahti
+ *
+ */
+public interface RepositoryState {
+
+	String getState();
+
+	void setState(String state);
+
+	boolean isInitial();
+
+	void setInitial(boolean initial);
+}

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryStateMachineModelFactory.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.data;
+
+import java.util.ArrayList;
+import java.util.Collection;
+
+import org.springframework.statemachine.config.model.ConfigurationData;
+import org.springframework.statemachine.config.model.DefaultStateMachineModel;
+import org.springframework.statemachine.config.model.StateData;
+import org.springframework.statemachine.config.model.StateMachineModel;
+import org.springframework.statemachine.config.model.StateMachineModelFactory;
+import org.springframework.statemachine.config.model.StatesData;
+import org.springframework.statemachine.config.model.TransitionData;
+import org.springframework.statemachine.config.model.TransitionsData;
+
+/**
+ * A generic {@link StateMachineModelFactory} which is backed by a Spring Data
+ * Repository abstraction.
+ *
+ * @author Janne Valkealahti
+ *
+ */
+public class RepositoryStateMachineModelFactory implements StateMachineModelFactory<String, String> {
+
+	private final StateRepository<? extends RepositoryState> stateRepository;
+	private final TransitionRepository<? extends RepositoryTransition> transitionRepository;
+
+	/**
+	 * Instantiates a new repository state machine model factory.
+	 *
+	 * @param stateRepository the state repository
+	 * @param transitionRepository the transition repository
+	 */
+	public RepositoryStateMachineModelFactory(StateRepository<? extends RepositoryState> stateRepository,
+			TransitionRepository<? extends RepositoryTransition> transitionRepository) {
+		this.stateRepository = stateRepository;
+		this.transitionRepository = transitionRepository;
+	}
+
+	@Override
+	public StateMachineModel<String, String> build() {
+		ConfigurationData<String, String> configurationData = new ConfigurationData<>();
+
+		Collection<StateData<String, String>> stateData = new ArrayList<>();
+		for (RepositoryState s : stateRepository.findAll()) {
+			stateData.add(new StateData<String, String>(s.getState(), s.isInitial()));
+		}
+		StatesData<String, String> statesData = new StatesData<>(stateData);
+
+		Collection<TransitionData<String, String>> transitionData = new ArrayList<>();
+		for (RepositoryTransition t : transitionRepository.findAll()) {
+			transitionData.add(new TransitionData<String, String>(t.getSource(), t.getTarget(), t.getEvent()));
+		}
+		TransitionsData<String, String> transitionsData = new TransitionsData<>(transitionData);
+
+		StateMachineModel<String, String> stateMachineModel = new DefaultStateMachineModel<>(configurationData, statesData, transitionsData);
+		return stateMachineModel;
+	}
+}

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/RepositoryTransition.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.data;
+
+/**
+ * Generic interface representing transition entity.
+ *
+ * @author Janne Valkealahti
+ *
+ */
+public interface RepositoryTransition {
+
+	String getSource();
+
+	void setSource(String source);
+
+	String getTarget();
+
+	void setTarget(String target);
+
+	String getEvent();
+
+	void setEvent(String event);
+}

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/StateRepository.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.data;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.NoRepositoryBean;
+import org.springframework.data.repository.Repository;
+
+/**
+ * Generic {@link Repository} interface for states.
+ *
+ * @author Janne Valkealahti
+ *
+ * @param <S> the state entity type
+ */
+@NoRepositoryBean
+public interface StateRepository<S extends RepositoryState> extends CrudRepository<S, Long> {
+}

spring-statemachine-data/src/main/java/org/springframework/statemachine/data/TransitionRepository.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.statemachine.data;
+
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.NoRepositoryBean;
+import org.springframework.data.repository.Repository;
+
+/**
+ * Generic {@link Repository} interface for transitions.
+ *
+ * @author Janne Valkealahti
+ *
+ * @param <T> the transition entity type
+ */
+@NoRepositoryBean
+public interface TransitionRepository<T extends RepositoryTransition> extends CrudRepository<T, Long> {
+}