Java tutorial
/* * Copyright 2015-2016 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 demo.web; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.Map; import javax.annotation.PostConstruct; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.HttpStatus; import org.springframework.messaging.Message; import org.springframework.messaging.handler.annotation.MessageExceptionHandler; import org.springframework.messaging.simp.SimpMessagingTemplate; import org.springframework.messaging.simp.annotation.SendToUser; import org.springframework.messaging.simp.annotation.SubscribeMapping; import org.springframework.messaging.support.MessageBuilder; import org.springframework.statemachine.StateMachine; import org.springframework.statemachine.StateMachineException; import org.springframework.statemachine.ensemble.EnsembleListenerAdapter; import org.springframework.statemachine.ensemble.StateMachineEnsemble; import org.springframework.statemachine.listener.StateMachineListenerAdapter; import org.springframework.statemachine.state.State; import org.springframework.statemachine.transition.Transition; import org.springframework.statemachine.transition.TransitionKind; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.bind.annotation.ResponseStatus; import demo.web.StateMachineConfig.Events; import demo.web.StateMachineConfig.States; @Controller public class StateMachineController { private final Log log = LogFactory.getLog(StateMachineController.class); @Autowired private SimpMessagingTemplate simpMessagingTemplate; @Autowired private StateMachine<States, Events> stateMachine; @Autowired private StateMachineEnsemble<States, Events> stateMachineEnsemble; @PostConstruct public void setup() { stateMachine.addStateListener(new StateMachineListenerAdapter<States, Events>() { @Override public void stateEntered(State<States, Events> state) { StateMachineMessage message = new StateMachineMessage(); message.setMessage("Enter state " + state.getId().toString()); simpMessagingTemplate.convertAndSend("/topic/sm.message", message); } @Override public void stateExited(State<States, Events> state) { StateMachineMessage message = new StateMachineMessage(); message.setMessage("Exit state " + state.getId().toString()); simpMessagingTemplate.convertAndSend("/topic/sm.message", message); } @Override public void stateChanged(State<States, Events> from, State<States, Events> to) { Map<Object, Object> variables = stateMachine.getExtendedState().getVariables(); ArrayList<StateMachineEvent> list = new ArrayList<StateMachineEvent>(); for (States state : stateMachine.getState().getIds()) { list.add(new StateMachineEvent(state.toString())); } simpMessagingTemplate.convertAndSend("/topic/sm.states", list); simpMessagingTemplate.convertAndSend("/topic/sm.variables", variables); } @Override public void transitionEnded(Transition<States, Events> transition) { if (transition != null && transition.getKind() == TransitionKind.INTERNAL) { Map<Object, Object> variables = stateMachine.getExtendedState().getVariables(); simpMessagingTemplate.convertAndSend("/topic/sm.variables", variables); } } @Override public void stateMachineError(StateMachine<States, Events> stateMachine, Exception exception) { handleStateMachineError(new StateMachineException("Received error from machine", exception)); } }); stateMachineEnsemble.addEnsembleListener(new EnsembleListenerAdapter<States, Events>() { @Override public void ensembleLeaderGranted(StateMachine<States, Events> stateMachine) { StateMachineMessage message = new StateMachineMessage(); message.setMessage("Leader granted " + stateMachine.getUuid().toString()); simpMessagingTemplate.convertAndSend("/topic/sm.message", message); } @Override public void ensembleLeaderRevoked(StateMachine<States, Events> stateMachine) { StateMachineMessage message = new StateMachineMessage(); message.setMessage("Leader revoked " + stateMachine.getUuid().toString()); simpMessagingTemplate.convertAndSend("/topic/sm.message", message); } }); } @SubscribeMapping("/sm.uuid") public String retrieveUuid() { return stateMachine.getUuid().toString(); } @SubscribeMapping("/sm.states") public Collection<StateMachineEvent> retrieveStates() { ArrayList<StateMachineEvent> list = new ArrayList<StateMachineEvent>(); for (States state : stateMachine.getState().getIds()) { list.add(new StateMachineEvent(state.toString())); } return list; } @SubscribeMapping("/sm.variables") public Map<Object, Object> retrieveVariables() { return stateMachine.getExtendedState().getVariables(); } @RequestMapping("/event") @ResponseStatus(HttpStatus.OK) public void sendEvent(@RequestParam(value = "id") Events id, @RequestParam(value = "testVariable", required = false) String testVariable) { log.info("Got request to send event " + id + " testVariable " + testVariable); Message<Events> message = MessageBuilder.withPayload(id).setHeader("testVariable", testVariable).build(); stateMachine.sendEvent(message); } @RequestMapping("/join") @ResponseStatus(HttpStatus.OK) public void joinEnsemble() { stateMachineEnsemble.join(stateMachine); } @RequestMapping("/leave") @ResponseStatus(HttpStatus.OK) public void leaveEnsemble() { stateMachineEnsemble.leave(stateMachine); } @RequestMapping(value = "/states", method = RequestMethod.GET, produces = "application/json") @ResponseBody public Collection<States> getStates() { return stateMachine.getState().getIds(); } @RequestMapping(value = "/status", method = RequestMethod.GET, produces = "application/json") @ResponseBody public Map<Object, Object> getStatus() { HashMap<Object, Object> map = new HashMap<Object, Object>(); map.put("hasStateMachineError", stateMachine.hasStateMachineError()); map.put("isComplete", stateMachine.isComplete()); map.put("extendedStateVariables", stateMachine.getExtendedState().getVariables()); return map; } @MessageExceptionHandler @SendToUser(value = "/queue/errors", broadcast = false) public String handleStateMachineError(StateMachineException e) { return e.getMessage(); } }