feat: 为状态机增加获取targetState、targetStateChain功能

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/State.java

@@ -36,6 +36,8 @@ public interface State<S,E,C> extends Visitable{
 
     List<Transition<S,E,C>> getEventTransitions(E event);
 
+    List<Transition<S,E,C>> getEventTransitions(E event, TransitionType transitionType);
+
     Collection<Transition<S,E,C>> getAllTransitions();
 
 }

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/StateChain.java

@@ -0,0 +1,45 @@
+package com.alibaba.cola.statemachine;
+
+import java.util.List;
+
+/**
+ * StateChain
+ *
+ * @author benym
+ * @date 2024/6/11 23:15
+ */
+public interface StateChain<S, E> extends StateChainVisitable {
+
+    /**
+     * Gets the source state of stateChain
+     *
+     * @return the source state
+     */
+    S getSource();
+
+    /**
+     * Gets the list of target states for stateChain
+     *
+     * @return the list of target states
+     */
+    List<S> getTargets();
+
+    /**
+     * Gets the event of stateChain
+     *
+     * @return event
+     */
+    E getEvent();
+
+    /**
+     * Print stateChain from the console
+     */
+    void showStateChain();
+
+    /**
+     * Generate the plantUml diagram of stateChain
+     *
+     * @return String
+     */
+    String generatePlantUml();
+}

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/StateChainVisitable.java

@@ -0,0 +1,18 @@
+package com.alibaba.cola.statemachine;
+
+/**
+ * StateChainVisitable
+ *
+ * @author benym
+ * @date 2024/6/12 18:07
+ */
+public interface StateChainVisitable {
+
+    /**
+     * accept StateChainVisitor and return visitor result
+     *
+     * @param visitor StateChainVisitor
+     * @return String
+     */
+    String accept(final StateChainVisitor visitor);
+}

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/StateChainVisitor.java

@@ -0,0 +1,31 @@
+package com.alibaba.cola.statemachine;
+
+import java.util.List;
+
+/**
+ * StateChainVisitor
+ *
+ * @author benym
+ * @date 2024/6/12 18:06
+ */
+public interface StateChainVisitor {
+
+    /**
+     * @param visitable the element to be visited.
+     * @return String
+     */
+    String visitOnEntry(StateChain<?, ?> visitable);
+
+    /**
+     * @param visitable the element to be visited.
+     * @return String
+     */
+    String visitOnExit(StateChain<?, ?> visitable);
+
+    /**
+     * @param chainStateList the element to be visited.
+     * @param event event
+     * @return String
+     */
+    <S, C, E> String visitOnStateChain(List<State<S,E,C>> chainStateList, E event);
+}

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/StateMachine.java

@@ -22,6 +22,38 @@ public interface StateMachine<S, E, C> extends Visitable{
      */
     boolean verify(S sourceStateId,E event);
 
+    /**
+     * Sending an event {@code E} to the state machine
+     * Calculate the subsequent states of the current sourceState in advance
+     * This method does not actually perform state transitions
+     * Such as a given state machine
+     * STATE1 --> STATE1 : EVENT1
+     * STATE1 --> STATE2 : EVENT1
+     * When the method's sourceState is STATE1 and event is EVENT1
+     * Will return Source: STATE1, Targets: [STATE1, STATE2], Event: EVENT1
+     *
+     * @param sourceState the source state
+     * @param event the event to send
+     * @return the target state list
+     */
+    List<S> getTargetStates(S sourceState, E event);
+
+    /**
+     * Sending an event {@code E} to the state machine
+     * Calculate the subsequent state chain of the current sourceState in advance
+     * This method does not actually perform state transitions
+     * Such as a given state machine
+     * STATE1 --> STATE2 : EVENT1
+     * STATE2 --> STATE3 : EVENT1
+     * When the method's sourceState is STATE1 and event is EVENT1
+     * Will return Source: STATE1, Targets: [STATE2, STATE3], Event: EVENT1
+     *
+     * @param sourceState   the source state
+     * @param event         the event to send
+     * @return the target state chain list
+     */
+    List<StateChain<S, E>> getTargetStateChain(S sourceState, E event);
+
     /**
      * Send an event {@code E} to the state machine.
      *

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/Transition.java

@@ -29,6 +29,8 @@ public interface Transition<S, E, C>{
     void setEvent(E event);
 
     void setType(TransitionType type);
+
+    TransitionType getType();
     /**
      * Gets the target state of this transition.
      *

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/impl/PlantUMLVisitor.java

@@ -1,17 +1,16 @@
 package com.alibaba.cola.statemachine.impl;
 
-import com.alibaba.cola.statemachine.State;
-import com.alibaba.cola.statemachine.StateMachine;
-import com.alibaba.cola.statemachine.Transition;
-import com.alibaba.cola.statemachine.Visitor;
+import com.alibaba.cola.statemachine.*;
+
+import java.util.List;
 
 /**
  * PlantUMLVisitor
  *
  * @author Frank Zhang
  * @date 2020-02-09 7:47 PM
  */
-public class PlantUMLVisitor implements Visitor {
+public class PlantUMLVisitor implements Visitor, StateChainVisitor {
 
     /**
      * Since the state machine is stateless, there is no initial state.
@@ -32,6 +31,30 @@ public String visitOnExit(StateMachine<?, ?, ?> visitable) {
         return "@enduml";
     }
 
+    @Override
+    public String visitOnEntry(StateChain<?, ?> visitable) {
+        return "@startuml" + LF;
+    }
+
+    @Override
+    public String visitOnExit(StateChain<?, ?> visitable) {
+        return "@enduml";
+    }
+
+    @Override
+    public <S, C, E> String visitOnStateChain(List<State<S, E, C>> chainStateList, E event) {
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < chainStateList.size() - 1; i++) {
+            sb.append(chainStateList.get(i).getId())
+                    .append("->")
+                    .append(chainStateList.get(i + 1).getId())
+                    .append(": ")
+                    .append(event)
+                    .append(LF);
+        }
+        return sb.toString();
+    }
+
     @Override
     public String visitOnEntry(State<?, ?, ?> state) {
         StringBuilder sb = new StringBuilder();

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/impl/StateChainImpl.java

@@ -0,0 +1,71 @@
+package com.alibaba.cola.statemachine.impl;
+
+import com.alibaba.cola.statemachine.State;
+import com.alibaba.cola.statemachine.StateChain;
+import com.alibaba.cola.statemachine.StateChainVisitor;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * StateChainImpl
+ *
+ * @author benym
+ * @date 2024/6/12 0:04
+ */
+public class StateChainImpl<S, E, C> implements StateChain<S, E> {
+
+    private final State<S, E, C> sourceState;
+
+    private final E event;
+
+    private final List<State<S, E, C>> targetStates;
+
+    public StateChainImpl(State<S, E, C> sourceState, E event, List<State<S, E, C>> targetStates) {
+        this.sourceState = sourceState;
+        this.event = event;
+        this.targetStates = targetStates;
+    }
+
+    @Override
+    public S getSource() {
+        return this.sourceState.getId();
+    }
+
+    @Override
+    public List<S> getTargets() {
+        return this.targetStates.stream().map(State::getId)
+                .collect(Collectors.toList());
+    }
+
+    @Override
+    public E getEvent() {
+        return this.event;
+    }
+
+    @Override
+    public void showStateChain() {
+        SysOutVisitor sysOutVisitor = new SysOutVisitor();
+        accept(sysOutVisitor);
+    }
+
+    @Override
+    public String generatePlantUml() {
+        PlantUMLVisitor plantUmlVisitor = new PlantUMLVisitor();
+        return accept(plantUmlVisitor);
+    }
+
+    @Override
+    public String accept(StateChainVisitor visitor) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(visitor.visitOnEntry(this));
+        List<State<S, E, C>> chainStateList = new ArrayList<>();
+        chainStateList.add(this.sourceState);
+        chainStateList.addAll(this.targetStates);
+        String row = visitor.visitOnStateChain(chainStateList, event);
+        sb.append(row);
+        sb.append(visitor.visitOnExit(this));
+        return sb.toString();
+    }
+}

cola-components/cola-component-statemachine/src/main/java/com/alibaba/cola/statemachine/impl/StateImpl.java

@@ -7,6 +7,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * StateImpl
@@ -52,6 +53,18 @@ public List<Transition<S, E, C>> getEventTransitions(E event) {
         return eventTransitions.get(event);
     }
 
+    @Override
+    public List<Transition<S, E, C>> getEventTransitions(E event, TransitionType transitionType) {
+        List<Transition<S, E, C>> transitionList = this.getEventTransitions(event);
+        if (transitionList == null || transitionList.isEmpty()) {
+            Debugger.debug("There is no Transition for " + event);
+            return new ArrayList<>();
+        }
+        return transitionList.stream()
+                .filter(transition-> transition.getType().equals(transitionType))
+                .collect(Collectors.toList());
+    }
+
     @Override
     public Collection<Transition<S, E, C>> getAllTransitions() {
         return eventTransitions.allTransitions();