update kafka-questions-01.md

Author: jacketfu0

docs/high-performance/message-queue/kafka-questions-01.md

@@ -277,9 +277,9 @@ public long nextBackOff() {
 ```
 那么这个 getMaxAttempts 的值又是多少呢？回到最开始，当执行出错会进入 DefaultErrorHandler 。DefaultErrorHandler 默认的构造函数是：
 ```Java
-  public DefaultErrorHandler() {
-		this(null, SeekUtils.DEFAULT_BACK_OFF);
-	}
+public DefaultErrorHandler() {
+  this(null, SeekUtils.DEFAULT_BACK_OFF);
+}
 ```
 SeekUtils.DEFAULT_BACK_OFF 定义的是 
 ```Java
@@ -297,21 +297,21 @@ DEFAULT_MAX_FAILURES 的值是10，currentAttempts从0到9，所以总共会执
 
 spring kafka 中只需要加上 `@DltHandler` 注解即可将重试失败的消息推到死信队列，死信队列的topic是在原 topic 后加上 '.DLT'。然后开启新的消费者消费死信队列即可。
 ```Java
-    @DltHandler
-    @KafkaListener(topics = {KafkaConst.TEST_TOPIC}, groupId = "apple")
-    private void customer(String message) {
-        log.info("kafka customer:{}", message);
-        Integer n = Integer.parseInt(message);
-        if (n % 5 == 0) {
-            throw new RuntimeException();
-        }
-        System.out.println(n);
-    }   
+@DltHandler
+@KafkaListener(topics = {KafkaConst.TEST_TOPIC}, groupId = "apple")
+private void customer(String message) {
+    log.info("kafka customer:{}", message);
+    Integer n = Integer.parseInt(message);
+    if (n % 5 == 0) {
+        throw new RuntimeException();
+    }
+    System.out.println(n);
+}   
 
-     @KafkaListener(topics = {KafkaConst.TEST_TOPIC + ".DLT"}, groupId = "apple")
-     private void delCustomer(String message) {
-       //
-     }
+@KafkaListener(topics = {KafkaConst.TEST_TOPIC + ".DLT"}, groupId = "apple")
+private void delCustomer(String message) {
+  //
+}
 ```
 ## 如何自定义重试次数，以及时间间隔
 "......，未完待续。"