diff --git a/W3/封装 .java b/W3/封装 .java
new file mode 100644
index 0000000..e46dc1c
--- /dev/null
+++ b/W3/封装 .java	
@@ -0,0 +1,45 @@
+public class BankAccount {
+    private String accountNumber;
+    private String ownerName;
+    private double balance;
+
+    public BankAccount(String accountNumber, String ownerName) {
+        this.accountNumber = accountNumber;
+        this.ownerName = ownerName;
+        this.balance = 0.0;
+    }
+
+    public String getAccountNumber() {
+        return this.accountNumber;
+    }
+
+    public String getOwnerName() {
+        return this.ownerName;
+    }
+
+    public void setOwnerName(String ownerName) {
+        this.ownerName = ownerName;
+    }
+
+    public double getBalance() {
+        return this.balance;
+    }
+
+    public void deposit(double amount) {
+        if (amount > 0) {
+            this.balance += amount;
+            System.out.println("存款成功，存入金额：" + amount);
+        } else {
+            System.out.println("存款失败：金额必须大于0");
+        }
+    }
+
+    public void withdraw(double amount) {
+        if (amount > 0 && amount <= this.balance) {
+            this.balance -= amount;
+            System.out.println("取款成功，取出金额：" + amount);
+        } else {
+            System.out.println("取款失败：金额必须大于0且不超过当前余额");
+        }
+    }
+}