diff --git a/w3/BankAccount.java b/w3/BankAccount.java
new file mode 100644
index 0000000..c504591
--- /dev/null
+++ b/w3/BankAccount.java
@@ -0,0 +1,84 @@
+public class BankAccount {
+   // 私有属性：账户号（final修饰，不可修改）
+   private final String accountNumber;
+   // 私有属性：户主姓名（可修改）
+   private String ownerName;
+   // 私有属性：余额（只能通过存款和取款操作改变）
+   private double balance;
+
+   /**
+    * 构造方法：创建账户时必须提供账户号和户主姓名，初始余额为0
+    * @param accountNumber 账户号（创建后不可修改）
+    * @param ownerName 户主姓名
+    */
+   public BankAccount(String accountNumber, String ownerName) {
+      this.accountNumber = accountNumber;
+      this.ownerName = ownerName;
+         this.balance = 0.0;
+      }
+      /// 获取账户号（只读，无setter方法）
+      /// @return 账户号
+      public String getAccountNumber() {
+         return accountNumber;
+      }
+
+      /**
+       * 获取户主姓名
+       * @return 户主姓名
+       */
+      public String getOwnerName() {
+         return ownerName;
+      }
+
+      /**
+       * 修改户主姓名
+       * @param ownerName 新的户主姓名
+       */
+      public void setOwnerName(String ownerName) {
+         this.ownerName = ownerName;
+         System.out.println("户主姓名已修改为：" + ownerName);
+      }
+
+      /**
+       * 查询余额（只读，无setter方法）
+       * @return 当前余额
+       */
+      public double getBalance() {
+         return balance;
+      }
+
+      /**
+       * 存款操作
+       * @param amount 存款金额（必须大于0）
+       */
+      public void deposit(double amount) {
+         if (amount > 0) {
+            balance += amount;
+            System.out.println("存款 " + amount + " 元成功，当前余额：" + balance + " 元");
+         } else {
+            System.out.println("存款金额必须大于0！");
+         }
+      }
+
+      /**
+       * 取款操作
+       * @param amount 取款金额（必须大于0且不超过当前余额）
+       */
+      public void withdraw(double amount) {
+         if (amount <= 0) {
+            System.out.println("取款金额必须大于0！");
+         } else if (amount > balance) {
+            System.out.println("余额不足！当前余额为 " + balance + " 元，无法取出 " + amount + " 元。");
+         } else {
+            balance -= amount;
+            System.out.println("取款 " + amount + " 元成功，当前余额：" + balance + " 元");
+         }
+      }
+
+      /**
+       * 查询余额并打印信息
+       */
+      public void queryBalance() {
+         System.out.println("账户 " + accountNumber + " 当前余额为：" + balance + " 元");
+      }
+   }
\ No newline at end of file
diff --git a/w3/Employee.java b/w3/Employee.java
new file mode 100644
index 0000000..5ee7ab8
--- /dev/null
+++ b/w3/Employee.java
@@ -0,0 +1,75 @@
+public class Employee {
+    // 私有属性：封装
+    private String id;
+    private String name;
+    private String department;
+    private double salary;
+
+    // 最低工资标准常量
+    private static final double MIN_SALARY = 2000.0;
+
+    // 全参构造方法
+    public Employee(String id, String name, String department, double salary) {
+        this.id = id;
+        this.name = name;
+        this.department = department;
+        // 使用 setSalary 来确保工资符合最低标准
+        setSalary(salary);
+    }
+
+    // Getter 和 Setter
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getDepartment() {
+        return department;
+    }
+
+    public void setDepartment(String department) {
+        this.department = department;
+    }
+
+    public double getSalary() {
+        return salary;
+    }
+
+    // 在 setSalary 中检查工资是否低于最低标准
+    public void setSalary(double salary) {
+        if (salary < MIN_SALARY) {
+            System.out.println("警告：工资不能低于最低工资 " + MIN_SALARY + " 元，已自动设置为最低工资。");
+            this.salary = MIN_SALARY;
+        } else {
+            this.salary = salary;
+        }
+    }
+
+    // 涨薪方法：percent 为 5 表示增加 5%
+    public void raiseSalary(double percent) {
+        if (percent <= 0) {
+            System.out.println("涨薪百分比必须大于 0");
+            return;
+        }
+        double increase = this.salary * (percent / 100);
+        double newSalary = this.salary + increase;
+        setSalary(newSalary); // 复用 setSalary 的校验逻辑
+    }
+
+    // 方便展示员工信息的方法
+    public void displayInfo() {
+        System.out.println("工号：" + id + "，姓名：" + name + "，部门：" + department + "，工资：" + salary);
+    }
+}
+