update:demo5

com/study/demo5/DataIO.java

@@ -0,0 +1,40 @@
+package com.study.demo5;
+
+import java.io.*;
+
+public class DataIO {
+  public void writeConfig(String path) {
+    try (DataOutputStream dos = new DataOutputStream(
+        new FileOutputStream(path))) {
+
+      dos.writeUTF("李华"); // 用户名
+      dos.writeInt(25); // 年龄
+      dos.writeBoolean(true); // 是否启用
+      dos.writeDouble(1234.56); // 余额
+
+      System.out.println("配置写入成功: " + path);
+
+    } catch (IOException e) {
+      System.err.println("写入配置失败: " + e.getMessage());
+    }
+  }
+
+  public void readConfig(String path) {
+    try (DataInputStream dis = new DataInputStream(
+        new FileInputStream(path))) {
+
+      String username = dis.readUTF();
+      int age = dis.readInt();
+      boolean enabled = dis.readBoolean();
+      double balance = dis.readDouble();
+
+      System.out.println("用户名: " + username);
+      System.out.println("年龄: " + age);
+      System.out.println("是否启用: " + enabled);
+      System.out.println("余额: " + balance);
+
+    } catch (IOException e) {
+      System.err.println("读取配置失败: " + e.getMessage());
+    }
+  }
+}