feat: finish bilingual session auth learning lab

web/WEB-INF/classes/com/demo/action/ValidationAction.java

@@ -15,13 +15,15 @@ public class ValidationAction extends ActionSupport {
     private String bio;
     private String scoreBand;
     private String submittedAt;
+    private boolean seniorTrack;
 
     @Override
     public String execute() {
         username = normalize(username);
         email = normalize(email);
         bio = normalize(bio);
-        scoreBand = age >= 30 ? "Mid-career operator profile" : "Early-career operator profile";
+        seniorTrack = age >= 30;
+        scoreBand = seniorTrack ? "mid" : "early";
         submittedAt = LocalDateTime.now().format(TIME_FORMATTER);
         return SUCCESS;
     }
@@ -29,16 +31,16 @@ public class ValidationAction extends ActionSupport {
     @Override
     public void validate() {
         if (username == null || username.trim().length() < 3 || username.trim().length() > 20) {
-            addFieldError("username", "Username must be between 3 and 20 characters.");
+            addFieldError("username", "用户名长度需在 3 到 20 之间。 / Username must be between 3 and 20 characters.");
         }
         if (email == null || !email.contains("@") || email.indexOf('@') == email.length() - 1) {
-            addFieldError("email", "Enter a valid email address.");
+            addFieldError("email", "请输入有效邮箱。 / Enter a valid email address.");
         }
         if (age == null || age < 18 || age > 60) {
-            addFieldError("age", "Age must be between 18 and 60.");
+            addFieldError("age", "年龄需在 18 到 60 之间。 / Age must be between 18 and 60.");
         }
         if (bio != null && bio.trim().length() > 240) {
-            addFieldError("bio", "Bio must stay under 240 characters.");
+            addFieldError("bio", "简介不能超过 240 个字符。 / Bio must stay under 240 characters.");
         }
     }
 
@@ -85,4 +87,8 @@ public class ValidationAction extends ActionSupport {
     public String getSubmittedAt() {
         return submittedAt;
     }
+
+    public boolean isSeniorTrack() {
+        return seniorTrack;
+    }
 }