Event

docs/spring/spring/README.md

@@ -2,6 +2,8 @@
 
 [SpringModulith简介](./SpringModulith简介.md)
 
+[Spring事件和事务的关系](./Spring事件和事务的关系.md)
+
 [BeanUtils使用注意事项](./BeanUtils.md)
 
 ## 进阶

docs/spring/spring/Spring事件和事务的关系.md

@@ -0,0 +1,152 @@
+# Spring事件和事务的关系
+
+Spring事务与ApplicationEventPublisher。
+
+代码地址：[spring-learn/spring-boot-event at main · lizhifuabc/spring-learn (github.com)](https://github.com/lizhifuabc/spring-learn/tree/main/spring-boot-event)
+
+```java
+@Transactional(rollbackFor = Exception.class)
+public void publishWithTransactional() {
+    Account account = new Account();
+    account.setName("lizhifu1");
+    account.setPassword("123456");
+
+    log.info("事务发送事件");
+    accountRepository.save(account);
+
+    AccountEvent accountEvent = new AccountEvent(account);
+    events.publishEvent(accountEvent);
+
+    account = new Account();
+    account.setName("lizhifu2");
+    account.setPassword("123456");
+    accountRepository.save(account);
+}
+```
+
+## 发送事件非异步
+
+```java
+@Slf4j
+@Component
+public class AccountEventListener {
+    @EventListener(AccountEvent.class)
+    public void onApplicationEvent(AccountEvent event) {
+        log.info("AccountEventListener 监听事件:{}",event.getSource());
+        throw new RuntimeException("AccountEventListener");
+    }
+}
+```
+
+此时数据都会回滚。
+
+## 发送事件异步执行
+
+```java
+@SpringBootApplication
+@EnableAsync
+public class SpringBootLogCustomApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(SpringBootLogCustomApplication.class);
+    }
+}
+
+```
+
+```java
+@Slf4j
+@Component
+public class AccountEventListener {
+    @EventListener(AccountEvent.class)
+    @Async
+    public void onApplicationEvent(AccountEvent event) {
+        log.info("AccountEventListener 监听事件:{}",event.getSource());
+        throw new RuntimeException("AccountEventListener");
+    }
+}
+```
+
+数据全部插入成功。
+
+## @TransactionalEventListener
+
+```java
+@Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@EventListener //类似注解继承
+public @interface TransactionalEventListener {
+	// 值：BEFORE_COMMIT、AFTER_COMMIT、AFTER_ROLLBACK、AFTER_COMPLETION
+	// 需要注意的是：AFTER_COMMIT + AFTER_COMPLETION是可以同时生效的
+	// AFTER_ROLLBACK + AFTER_COMPLETION是可以同时生效的
+	TransactionPhase phase() default TransactionPhase.AFTER_COMMIT;
+
+	// 表明若没有事务的时候，对应的event是否需要执行，默认值为false表示，没事务就不执行了。
+	boolean fallbackExecution() default false;
+
+	// 使用@AliasFor的能力，放到了@EventListener身上
+	// 注意：一般建议都需要指定此值，否则默认可以处理所有类型的事件，范围太广了。
+	@AliasFor(annotation = EventListener.class, attribute = "classes")
+	Class<?>[] value() default {};
+	@AliasFor(annotation = EventListener.class, attribute = "classes")
+	Class<?>[] classes() default {};
+
+	String condition() default "";
+}
+```
+
+```java
+public enum TransactionPhase {
+   // 在事务commit之前执行
+   BEFORE_COMMIT,
+
+   // 在事务commit之后执行
+    AFTER_COMMIT,
+
+    // 在事务rollback之后执行
+    AFTER_ROLLBACK,
+
+   // 在事务完成时执行，这里的完成是指无论事务是成功提交还是事务回滚了
+   AFTER_COMPLETION
+  }
+```
+
+### 指定TransactionPhase
+
+```java
+@Transactional(rollbackFor = Exception.class)
+    public void publishWithTransactional() {
+        Account account = new Account();
+        account.setName("lizhifu1");
+        account.setPassword("123456");
+
+        log.info("事务发送事件");
+        accountRepository.save(account);
+
+        AccountEvent accountEvent = new AccountEvent(account);
+        events.publishEvent(accountEvent);
+
+        account = new Account();
+        account.setName("lizhifu2");
+        account.setPassword("123456");
+        accountRepository.save(account);
+
+        throw new RuntimeException("publishWithTransactional");
+    }
+}
+```
+
+```java
+@Slf4j
+@Component
+public class AccountEventListener {
+    @Async
+    @TransactionalEventListener(value = AccountEvent.class,phase = TransactionPhase.AFTER_COMMIT)
+    public void onApplicationEvent(AccountEvent event) {
+        log.info("AccountEventListener 监听事件:{}",event.getSource());
+        throw new RuntimeException("AccountEventListener");
+    }
+}
+```
+
+此时虽然添加了@Async，但是由于制定了TransactionPhase为AFTER_COMMIT，所以方法不执行。