feat: use an enhanced CypherAPI to refactor it

hugegraph-api/src/main/java/org/apache/hugegraph/api/cypher/CypherManager.java

@@ -30,6 +30,7 @@
 
 @ThreadSafe
 public final class CypherManager {
+
     private final String configurationFile;
     private YAMLConfiguration configuration;
 
@@ -49,30 +50,28 @@ public CypherClient getClient(String userName, String password) {
         E.checkArgument(password != null && !password.isEmpty(),
                         "The password parameter can't be null or empty");
 
-        //TODO: Need to cache the client and make it hold the connection.
+        // TODO: Need to cache the client and make it hold the connection.
         return new CypherClient(userName, password, this::cloneConfig);
     }
 
     public CypherClient getClient(String token) {
         E.checkArgument(token != null && !token.isEmpty(),
                         "The token parameter can't be null or empty");
 
-        //TODO: Need to cache the client and make it hold the connection.
+        // TODO: Need to cache the client and make it hold the connection.
         return new CypherClient(token, this::cloneConfig);
     }
 
     private Configuration cloneConfig() {
         if (this.configuration == null) {
             this.configuration = loadYaml(this.configurationFile);
         }
-
         return (Configuration) this.configuration.clone();
     }
 
     private static YAMLConfiguration loadYaml(String configurationFile) {
         File yamlFile = getConfigFile(configurationFile);
         YAMLConfiguration yaml;
-
         try {
             Reader reader = new FileReader(yamlFile);
             yaml = new YAMLConfiguration();
@@ -81,27 +80,22 @@ private static YAMLConfiguration loadYaml(String configurationFile) {
             throw new RuntimeException(String.format("Failed to load configuration file," +
                                                      " the file at '%s'.", configurationFile), e);
         }
-
         return yaml;
     }
 
     private static File getConfigFile(String configurationFile) {
-        final File systemFile = new File(configurationFile);
-
+        File systemFile = new File(configurationFile);
         if (!systemFile.exists()) {
-            final ClassLoader currentClassLoader = Thread.currentThread().getContextClassLoader();
-            final URL resource = currentClassLoader.getResource(configurationFile);
+            ClassLoader currentClassLoader = Thread.currentThread().getContextClassLoader();
+            URL resource = currentClassLoader.getResource(configurationFile);
             assert resource != null;
-            final File resourceFile = new File(resource.getFile());
-
+            File resourceFile = new File(resource.getFile());
             if (!resourceFile.exists()) {
                 throw new IllegalArgumentException(String.format("Configuration file at '%s' does" +
                                                                  " not exist", configurationFile));
             }
             return resourceFile;
-
         }
-
         return systemFile;
     }
 }

hugegraph-api/src/main/java/org/apache/hugegraph/auth/StandardAuthenticator.java

@@ -216,6 +216,7 @@ public static void initAdminUserIfNeeded(String confFile) throws Exception {
     }
 
     private class TokenSaslAuthenticator implements SaslNegotiator {
+
         private static final byte NUL = 0;
         private String username;
         private String password;
@@ -261,16 +262,15 @@ private void decode(byte[] bytes) throws AuthenticationException {
             int end = bytes.length;
 
             for (int i = bytes.length - 1; i >= 0; i--) {
-                if (bytes[i] == NUL) {
-                    if (this.password == null) {
-                        password = new String(Arrays.copyOfRange(bytes, i + 1, end),
-                                              StandardCharsets.UTF_8);
-                    } else if (this.username == null) {
-                        username = new String(Arrays.copyOfRange(bytes, i + 1, end),
-                                              StandardCharsets.UTF_8);
-                    }
-                    end = i;
+                if (bytes[i] != NUL) continue;
+                if (this.password == null) {
+                    password = new String(Arrays.copyOfRange(bytes, i + 1, end),
+                                          StandardCharsets.UTF_8);
+                } else if (this.username == null) {
+                    username = new String(Arrays.copyOfRange(bytes, i + 1, end),
+                                          StandardCharsets.UTF_8);
                 }
+                end = i;
             }
 
             if (this.username == null) {