diff --git a/w3/BankAccount.java b/w3/BankAccount.java
new file mode 100644
index 0000000..6ffc1a9
--- /dev/null
+++ b/w3/BankAccount.java
@@ -0,0 +1,50 @@
+public class BankAccount{
+    private final 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 accountNumber;
+    }
+
+    public String getOwnerName(){
+        return ownerName;
+    }
+
+    public void setOwnerName(String ownerName) {
+        if (ownerName == null || ownerName.isBlank()) {
+            throw new IllegalArgumentException("invalid ownerName");
+        }
+        this.ownerName = ownerName.strip();
+    }
+
+    public double getBalance(){
+        return balance;
+    }
+
+    public void deposit(double amount){
+        if (amount > 0){
+            balance += amount;
+            System.out.println("存款成功，当前余额为"+balance+"元");
+        } else {
+            System.out.println("存款金额必须大于0");
+        }
+    }
+
+    public void withdraw(double amount){
+        if (amount>0 && amount<=balance){
+            balance -= amount;
+            System.out.println("取款成功，当前余额为"+balance+"元");
+        } else if (amount<=0){
+            System.out.println("取款金额必须大于0");
+        } else {
+            System.out.println("取款金额不能超过当前余额");
+        }
+    }
+}
\ No newline at end of file
diff --git a/w3/TestBankAccount.java b/w3/TestBankAccount.java
new file mode 100644
index 0000000..1ac003a
--- /dev/null
+++ b/w3/TestBankAccount.java
@@ -0,0 +1,19 @@
+public class TestBankAccount {
+    public static void main(String[] args){
+        BankAccount account = new BankAccount("abc123","zj");
+
+        System.out.println("当前余额：" + account.getBalance());
+
+        account.deposit(500);
+        account.deposit(-100);
+
+        account.withdraw(200);
+        account.withdraw(400);
+        account.withdraw(-50);
+
+        account.setOwnerName("ZJ123");
+        System.out.println("修改后户主：" + account.getOwnerName());
+
+        System.out.println("当前余额：" + account.getBalance());
+    }
+}
diff --git a/w3/程序运行截图.jpg b/w3/程序运行截图.jpg
new file mode 100644
index 0000000..f80f1db
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