From 4c7c3d334559fdb3516daf4e62306ea8bd52dcb9 Mon Sep 17 00:00:00 2001
From: kimscott <sanaloveyou@uengine.org>
Date: Mon, 10 Feb 2020 13:34:44 +0900
Subject: [PATCH] add saga rollback

---
 .../com/example/template/Application.java     |  2 +-
 .../example/template/ProductController.java   | 10 +++++-
 .../example/template/ProductOutOfStock.java   | 36 +++++++++++++++++++
 .../com/example/template/ProductService.java  | 20 ++++++++---
 4 files changed, 62 insertions(+), 6 deletions(-)
 create mode 100644 src/main/java/com/example/template/ProductOutOfStock.java

diff --git a/src/main/java/com/example/template/Application.java b/src/main/java/com/example/template/Application.java
index 8ddda12..c934510 100644
--- a/src/main/java/com/example/template/Application.java
+++ b/src/main/java/com/example/template/Application.java
@@ -28,7 +28,7 @@ public class Application {
             product.setImageUrl("https://github.githubassets.com/images/modules/profile/profile-joined-github.png");
             product.setName(p);
             product.setPrice(i*10000);
-            product.setStock(i*1000000);
+            product.setStock(i*10);
             product.setImageUrl("/goods/img/"+p+".jpg");
 
             // 상품 디테일 추가 - 양방향 관계
diff --git a/src/main/java/com/example/template/ProductController.java b/src/main/java/com/example/template/ProductController.java
index dc59543..ed7c630 100644
--- a/src/main/java/com/example/template/ProductController.java
+++ b/src/main/java/com/example/template/ProductController.java
@@ -1,6 +1,7 @@
 package com.example.template;
 
 import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
+import com.netflix.hystrix.contrib.javanica.annotation.HystrixProperty;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -48,7 +49,14 @@ public class ProductController {
 
 
     @PatchMapping("/product/{productId}")
-    @HystrixCommand(fallbackMethod = "certifyFallBack")
+    @HystrixCommand(
+            fallbackMethod = "certifyFallBack",
+            commandProperties = {
+                    @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "1000"), // 기본 타임아웃
+                    @HystrixProperty(name = "circuitBreaker.errorThresholdPercentage", value = "50"), // 서킷브레이커가 작하게될 에러 퍼센트
+                    @HystrixProperty(name = "circuitBreaker.requestVolumeThreshold", value = "20"), // 서킷브레이커가 열리기 위한 최소 요청조 (10초간 19번이 실패해도 서킷은 오픈 안됨)
+                    @HystrixProperty(name = "circuitBreaker.sleepWindowInMilliseconds", value = "5000") } // 서킷브래이커가 열렸을때 얼마나 유지할지
+    )
     ResponseEntity<String> fakeProductPatch(@PathVariable(value = "productId") Long productId, @RequestBody String data) {
 
         count++;
diff --git a/src/main/java/com/example/template/ProductOutOfStock.java b/src/main/java/com/example/template/ProductOutOfStock.java
new file mode 100644
index 0000000..2c486ce
--- /dev/null
+++ b/src/main/java/com/example/template/ProductOutOfStock.java
@@ -0,0 +1,36 @@
+package com.example.template;
+
+public class ProductOutOfStock extends AbstractEvent {
+
+    private String stateMessage = "재고량 바닥";
+    private Long productId;
+    private Long orderId;
+
+    public ProductOutOfStock(){
+        super();
+    }
+
+    public String getStateMessage() {
+        return stateMessage;
+    }
+
+    public void setStateMessage(String stateMessage) {
+        this.stateMessage = stateMessage;
+    }
+
+    public Long getProductId() {
+        return productId;
+    }
+
+    public void setProductId(Long productId) {
+        this.productId = productId;
+    }
+
+    public Long getOrderId() {
+        return orderId;
+    }
+
+    public void setOrderId(Long orderId) {
+        this.orderId = orderId;
+    }
+}
diff --git a/src/main/java/com/example/template/ProductService.java b/src/main/java/com/example/template/ProductService.java
index 246c20b..8122233 100644
--- a/src/main/java/com/example/template/ProductService.java
+++ b/src/main/java/com/example/template/ProductService.java
@@ -37,7 +37,17 @@ public class ProductService {
                 Product product = productOptional.get();
                 product.setStock(product.getStock() - orderPlaced.getQuantity());
 
-                productRepository.save(product);
+                if( product.getStock() < 0 ){
+                    System.out.println("productOutOfStock 이벤트 발생");
+                    ProductOutOfStock productOutOfStock = new ProductOutOfStock();
+                    productOutOfStock.setProductId(orderPlaced.getProductId());
+                    productOutOfStock.setOrderId(orderPlaced.getOrderId());
+                    productOutOfStock.publish();
+
+                }else{
+                    productRepository.save(product);
+                }
+
 
             }
 
@@ -47,9 +57,11 @@ public class ProductService {
             if( orderPlaced.getEventType().equals(OrderCancelled.class.getSimpleName())){
                 Optional<Product> productOptional = productRepository.findById(orderPlaced.getProductId());
                 Product product = productOptional.get();
-                product.setStock(product.getStock() + orderPlaced.getQuantity());
-
-                productRepository.save(product);
+                // productOutOfStock 상황이 아닐때만 재고량을 늘린다.
+                if( product.getStock() - orderPlaced.getQuantity() > 0 ){
+                    product.setStock(product.getStock() + orderPlaced.getQuantity());
+                    productRepository.save(product);
+                }
             }
 
         }catch (Exception e){