BAEL-2435 Introduce Query message logic

smcvb · smcvb · commit 769af6759ed6 · 2018-12-27T10:39:42.000+01:00
Introduce a FindAllOrderedProductsQuery query message, which is
published on the QueryGateway through the OrderRestEndpoint and handled
by the OrderedProductsEventHandler
diff --git a/axon/src/main/java/com/baeldung/axon/coreapi/queries/FindAllOrderedProductsQuery.java b/axon/src/main/java/com/baeldung/axon/coreapi/queries/FindAllOrderedProductsQuery.java
@@ -0,0 +1,5 @@
+package com.baeldung.axon.coreapi.queries;
+
+public class FindAllOrderedProductsQuery {
+
+}
diff --git a/axon/src/main/java/com/baeldung/axon/gui/OrderRestEndpoint.java b/axon/src/main/java/com/baeldung/axon/gui/OrderRestEndpoint.java
@@ -1,24 +1,32 @@
 package com.baeldung.axon.gui;
 
+import java.util.List;
 import java.util.UUID;
 
 import org.axonframework.commandhandling.gateway.CommandGateway;
+import org.axonframework.messaging.responsetypes.ResponseTypes;
+import org.axonframework.queryhandling.QueryGateway;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 import com.baeldung.axon.coreapi.commands.ConfirmOrderCommand;
 import com.baeldung.axon.coreapi.commands.PlaceOrderCommand;
 import com.baeldung.axon.coreapi.commands.ShipOrderCommand;
+import com.baeldung.axon.coreapi.queries.FindAllOrderedProductsQuery;
+import com.baeldung.axon.coreapi.queries.OrderedProduct;
 
 @RestController
 public class OrderRestEndpoint {
 
     private static final String DEFAULT_PRODUCT = "Deluxe Chair";
 
     private final CommandGateway commandGateway;
+    private final QueryGateway queryGateway;
 
-    public OrderRestEndpoint(CommandGateway commandGateway) {
+    public OrderRestEndpoint(CommandGateway commandGateway, QueryGateway queryGateway) {
         this.commandGateway = commandGateway;
+        this.queryGateway = queryGateway;
     }
 
     @PostMapping("/ship-order")
@@ -37,4 +45,10 @@ public void shipUnconfirmedOrder() {
         commandGateway.send(new ShipOrderCommand(orderId));
     }
 
+    @GetMapping("/all-orders")
+    public List<OrderedProduct> findAllOrderedProducts() {
+        return queryGateway.query(new FindAllOrderedProductsQuery(), ResponseTypes.multipleInstancesOf(OrderedProduct.class))
+            .join();
+    }
+
 }
diff --git a/axon/src/main/java/com/baeldung/axon/querymodel/OrderedProductsEventHandler.java b/axon/src/main/java/com/baeldung/axon/querymodel/OrderedProductsEventHandler.java
@@ -1,15 +1,19 @@
 package com.baeldung.axon.querymodel;
 
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.axonframework.eventhandling.EventHandler;
+import org.axonframework.queryhandling.QueryHandler;
 import org.springframework.stereotype.Service;
 
-import com.baeldung.axon.coreapi.queries.OrderedProduct;
 import com.baeldung.axon.coreapi.events.OrderConfirmedEvent;
 import com.baeldung.axon.coreapi.events.OrderPlacedEvent;
 import com.baeldung.axon.coreapi.events.OrderShippedEvent;
+import com.baeldung.axon.coreapi.queries.FindAllOrderedProductsQuery;
+import com.baeldung.axon.coreapi.queries.OrderedProduct;
 
 @Service
 public class OrderedProductsEventHandler {
@@ -39,4 +43,9 @@ public void on(OrderConfirmedEvent event) {
         });
     }
 
+    @QueryHandler
+    public List<OrderedProduct> handle(FindAllOrderedProductsQuery query) {
+        return new ArrayList<>(orderedProducts.values());
+    }
+
 }

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +package com.baeldung.axon.coreapi.queries;
++
 +public class FindAllOrderedProductsQuery {
++
 +}