### 序列化&反序列化 JAVA序列化的缺點 * 無法跨語言 * 序列化后的碼流太大 * 序列化性能太低 ObjectOutputStream/ObjectInputStream ``` import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.ObjectOutputStream; import java.io.Serializable; public class Appliction { public static void main(String[] args) throws IOException { try (ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); ObjectOutputStream out = new ObjectOutputStream(outputStream)) { User user = new User("John", 28); out.writeObject(user); out.close(); outputStream.close(); System.err.println("==>" + outputStream.toByteArray()); } catch (Exception e) { e.printStackTrace(); } } static class User implements Serializable { private String name; private int age; public User(String name, int age) { this.name = name; this.age = age; } public String getName() { return name; } public void setName(String name) { this.name = name; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } } } ``` ObjectOutputStream\(outputStream\)：往流中寫入STREAM\_MAGIC和STREAM\_VERSION writeObject\(Object object\)：在writeObject時，首先要做的是獲取當前序列化對象的類信息，在獲取類信息時，調用的是ObjectStreamClass的lookup方法；