[fit] solve review comments

Author: Mai-icy

framework/fit/java/fit-builtin/services/fit-http-classic/definition/src/main/java/modelengine/fit/http/support/DefaultCookieCollection.java

@@ -13,6 +13,7 @@
 import modelengine.fit.http.header.ConfigurableCookieCollection;
 import modelengine.fit.http.header.CookieCollection;
 import modelengine.fit.http.util.HttpUtils;
+import modelengine.fitframework.util.CollectionUtils;
 import modelengine.fitframework.util.StringUtils;
 
 import java.util.ArrayList;
@@ -35,26 +36,26 @@ public class DefaultCookieCollection implements ConfigurableCookieCollection {
 
     @Override
     public Optional<Cookie> get(String name) {
-        List<Cookie> cookies = store.get(name);
-        if (cookies == null || cookies.isEmpty()) {
+        List<Cookie> cookies = this.store.get(name);
+        if (CollectionUtils.isEmpty(cookies)) {
             return Optional.empty();
         }
         return Optional.of(cookies.get(0));
     }
 
     @Override
     public List<Cookie> all(String name) {
-        return store.getOrDefault(name, Collections.emptyList());
+        return this.store.getOrDefault(name, Collections.emptyList());
     }
 
     @Override
     public List<Cookie> all() {
-        return store.values().stream().flatMap(List::stream).collect(Collectors.toList());
+        return this.store.values().stream().flatMap(List::stream).collect(Collectors.toList());
     }
 
     @Override
     public int size() {
-        return store.values().stream().mapToInt(List::size).sum();
+        return this.store.values().stream().mapToInt(List::size).sum();
     }
 
     @Override
@@ -63,10 +64,10 @@ public void add(Cookie cookie) {
             return;
         }
         if (HttpUtils.isInvalidCookiePair(cookie.name(), cookie.value())) {
-            throw new IllegalArgumentException("Invalid cookie: name or value is not allowed");
+            throw new IllegalArgumentException("Invalid cookie: name or value is not allowed.");
         }
-        store.computeIfAbsent(cookie.name(), k -> new ArrayList<>());
-        List<Cookie> list = store.get(cookie.name());
+        this.store.computeIfAbsent(cookie.name(), k -> new ArrayList<>());
+        List<Cookie> list = this.store.get(cookie.name());
         list.removeIf(c -> Objects.equals(c.path(), cookie.path()) && Objects.equals(c.domain(), cookie.domain()));
         list.add(cookie);
     }

framework/fit/java/fit-builtin/services/fit-http-classic/definition/src/main/java/modelengine/fit/http/util/HttpUtils.java

@@ -236,7 +236,7 @@ private static void parseCookieAttributes(String[] parts, Cookie.Builder builder
      * @return 如果 name 和 value 都合法返回 {@code true}，否则返回 {@code false}。
      */
     public static boolean isInvalidCookiePair(String name, String value) {
-        if (name == null || name.isEmpty() || !TOKEN_PATTERN.matcher(name).matches()) {
+        if (StringUtils.isEmpty(name) || !TOKEN_PATTERN.matcher(name).matches()) {
             return true;
         }
         if (value == null) {