refactor: Optimsed codes.

Move private and protected methods or fields to the last of java files.

simple-jwt-facade/src/main/java/cn/org/codecrafters/simplejwt/SecretCreator.java

@@ -32,36 +32,6 @@ import java.util.Random;
  */
 public final class SecretCreator {
 
-    /**
-     * Private constructor to prevent instantiation
-     */
-    private SecretCreator() {
-    }
-
-    /**
-     * The string containing all lowercase characters that can be used to
-     * generate the secret.
-     */
-    private static final String LOWERCASE_CHARACTERS = "abcdefghijklmnopqrstuvwxyz";
-
-    /**
-     * The string containing all uppercase characters that can be used to
-     * generate the secret.
-     */
-    private static final String UPPERCASE_CHARACTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
-
-    /**
-     * The string containing all digit characters that can be used to generate
-     * the secret.
-     */
-    private static final String DIGITS = "0123456789";
-
-    /**
-     * The string containing all special sign characters that can be used to
-     * generate the secret.
-     */
-    private static final String SPECIAL_SIGNS = "!@#$%^&,*()_+-=,[]{}|;:,'\",.<>/?";
-
     /**
      * Generates a secure secret with the specified length and character sets.
      *
@@ -153,4 +123,33 @@ public final class SecretCreator {
         return createSecret(length, false, false, false);
     }
 
+    /**
+     * Private constructor will protect this class from being instantiated.
+     */
+    private SecretCreator() {
+    }
+
+    /**
+     * The string containing all lowercase characters that can be used to
+     * generate the secret.
+     */
+    private static final String LOWERCASE_CHARACTERS = "abcdefghijklmnopqrstuvwxyz";
+
+    /**
+     * The string containing all uppercase characters that can be used to
+     * generate the secret.
+     */
+    private static final String UPPERCASE_CHARACTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+
+    /**
+     * The string containing all digit characters that can be used to generate
+     * the secret.
+     */
+    private static final String DIGITS = "0123456789";
+
+    /**
+     * The string containing all special sign characters that can be used to
+     * generate the secret.
+     */
+    private static final String SPECIAL_SIGNS = "!@#$%^&,*()_+-=,[]{}|;:,'\",.<>/?";
 }

simple-jwt-facade/src/main/java/cn/org/codecrafters/simplejwt/constants/PredefinedKeys.java

@@ -88,11 +88,7 @@ public final class PredefinedKeys {
     public static final List<String> KEYS = List.of(ISSUER, SUBJECT, AUDIENCE, EXPIRATION_TIME, NOT_BEFORE, ISSUED_AT, JWT_ID);
 
     /**
-     * Private constructor to prevent instantiation of the
-     * {@code PredefinedKeys} class.
-     * <p>
-     * This class is intended to be used as a utility class with only static
-     * constants and methods.
+     * Private constructor will protect this class from being instantiated.
      */
     private PredefinedKeys() {
     }

simple-jwt-facade/src/main/java/cn/org/codecrafters/simplejwt/constants/TokenDataType.java

@@ -63,6 +63,9 @@ public enum TokenDataType {
      */
     private final Class<?> mappedClass;
 
+    /**
+     * Create a TokenDataType with a mapped class.
+     */
     TokenDataType(Class<?> mappedClass) {
         this.mappedClass = mappedClass;
     }