143 lines
4.2 KiB
Java
143 lines
4.2 KiB
Java
package ru.bvn13.fsm;
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import ru.bvn13.fsm.Exceptions.*;
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import java.util.ArrayList;
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import java.util.HashMap;
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import java.util.List;
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import java.util.Map;
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/**
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* Created by bvn13 on 28.12.2017.
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*/
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public class FSM {
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private boolean done = false;
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private State initialState;
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private State currentState;
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private State previousState;
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private Map<String, State> states;
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private Map<String, Map<String, ConditionBehaviour>> transitions;
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public FSM() {
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this.states = new HashMap<>();
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this.transitions = new HashMap<>();
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}
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private void checkStateExist(String name) throws StateExistsException {
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if (this.states.containsKey(name)) {
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throw new StateExistsException(name);
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}
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}
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public void init() throws NotInitedException {
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currentState = initialState;
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if (currentState == null) {
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throw new NotInitedException();
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}
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done = false;
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previousState = null;
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currentState.beforeEvent();
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currentState.process();
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}
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public State getCurrentState() {
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return currentState;
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}
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public State getPreviousState() {
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return previousState;
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}
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public void next() throws FSMException {
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if (done) {
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return;
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}
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currentState.afterEvent();
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if (currentState.isFinish()) {
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done = true;
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return;
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}
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if (!transitions.containsKey(currentState.getName())) {
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throw new TransitionMissedException(currentState.getName());
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}
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Map<String, ConditionBehaviour> conditions = transitions.get(currentState.getName());
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List<String> nextStates = new ArrayList<>();
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for (String key : conditions.keySet()) {
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if (conditions.get(key) == null) {
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nextStates.add(key);
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} else if(conditions.get(key).check()) {
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nextStates.add(key);
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}
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}
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if (nextStates.size() > 1) {
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throw new AmbiguousTransitionException(currentState.getName(), nextStates);
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}
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if (nextStates.size() == 0) {
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throw new BrokenTransitionException(currentState.getName());
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}
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State nextState = states.get(nextStates.get(0));
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nextState(nextState);
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}
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public void prev() throws FSMException {
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if (done) {
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return;
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}
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currentState.afterEvent();
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if (getPreviousState() == null) {
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return;
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}
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nextState(getPreviousState());
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}
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private void nextState(State state) {
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state.beforeEvent();
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previousState = currentState;
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currentState = state;
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currentState.process();
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}
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public void initState(State state) throws FSMException {
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state.setFSM(this);
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addState(state);
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initialState = state;
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}
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public void addState(State state) throws FSMException {
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checkStateExist(state.getName());
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state.setFSM(this);
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this.states.put(state.getName(), state);
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}
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public void addTransition(String fromState, String toState) throws FSMException {
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storeTransition(fromState, toState, null);
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}
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public void addTransition(String fromState, String toState, Condition condition) throws FSMException {
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condition.setFSM(this);
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storeTransition(fromState, toState, condition);
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}
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public void addTransition(String fromState, State toState) throws FSMException {
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addState(toState);
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addTransition(fromState, toState.getName());
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}
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public void addTransition(String fromState, State toState, Condition condition) throws FSMException {
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addState(toState);
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addTransition(fromState, toState.getName(), condition);
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}
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private void storeTransition(String fromState, String toState, Condition condition) throws FSMException {
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if (!transitions.containsKey(fromState)) {
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transitions.put(fromState, new HashMap<>());
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}
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if (transitions.get(fromState).containsKey(toState)) {
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throw new ConditionExistsException(fromState, toState);
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}
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transitions.get(fromState).put(toState, condition);
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}
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}
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