Initial commit

src/main/java/com/mzh/library/entity/Role.java

@@ -0,0 +1,40 @@
+package com.mzh.library.entity;
+
+import java.util.Locale;
+
+public enum Role {
+    ADMINISTRATOR("administrator", "Administrator"),
+    LIBRARIAN("librarian", "Librarian"),
+    READER("reader", "Reader");
+
+    private final String code;
+    private final String displayName;
+
+    Role(String code, String displayName) {
+        this.code = code;
+        this.displayName = displayName;
+    }
+
+    public String getCode() {
+        return code;
+    }
+
+    public String getDisplayName() {
+        return displayName;
+    }
+
+    public static Role fromCode(String code) {
+        if (code == null || code.trim().isEmpty()) {
+            throw new IllegalArgumentException("Role code is required");
+        }
+
+        String normalized = code.trim().toLowerCase(Locale.ROOT);
+        for (Role role : values()) {
+            if (role.code.equals(normalized)) {
+                return role;
+            }
+        }
+
+        throw new IllegalArgumentException("Unsupported role code: " + code);
+    }
+}