refactor: delete EtcdRefresherHandler redundant comments (#1554)

* refactor: delete EtcdRefresherHandler redundant comments

* refactor: refactor JsonConfigParser import classes

kernel/dynamic/mode/config/src/main/java/cn/hippo4j/threadpool/dynamic/mode/config/parser/JsonConfigParser.java

@@ -23,7 +23,12 @@ import org.apache.commons.collections.MapUtils;
 import org.apache.commons.lang3.StringUtils;
 
 import java.io.IOException;
-import java.util.*;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 
 /**
  * Json config parser.

starters/threadpool/config/src/main/java/cn/hippo4j/config/springboot/starter/refresher/EtcdRefresherHandler.java

@@ -17,7 +17,6 @@
 
 package cn.hippo4j.config.springboot.starter.refresher;
 
-import cn.hippo4j.common.toolkit.JSONUtil;
 import cn.hippo4j.common.toolkit.StringUtil;
 import cn.hippo4j.threadpool.dynamic.mode.config.properties.BootstrapConfigProperties;
 import io.etcd.jetcd.ByteSequence;
@@ -65,7 +64,6 @@ public class EtcdRefresherHandler extends AbstractConfigThreadPoolDynamicRefresh
         String key = etcd.get(KEY);
         Charset charset = StringUtil.isBlank(etcd.get(CHARSET)) ? StandardCharsets.UTF_8 : Charset.forName(etcd.get(CHARSET));
         initClient(etcd, charset);
-        // TODO Currently only supports json
         GetResponse getResponse = client.getKVClient().get(ByteSequence.from(key, charset)).get();
         KeyValue keyValue = getResponse.getKvs().get(0);
         if (Objects.isNull(keyValue)) {
@@ -103,7 +101,6 @@ public class EtcdRefresherHandler extends AbstractConfigThreadPoolDynamicRefresh
      * @param charset charset
      */
     private void initClient(Map<String, String> etcd, Charset charset) {
-        // TODO
         if (Objects.isNull(client)) {
             String user = etcd.get(USER);
             String password = etcd.get(PASSWORD);