了解InvalidClassException异常
InvalidClassException是Java中的一个受检异常，通常在进行序列化和反序列化操作时发生。它表明类的序列化版本与从流中读取的类描述符的类型不匹配，或者在加载序列化类的过程中找不到该类。
处理方法
1. 序列化版本号匹配
在进行对象的序列化和反序列化时，确保类的序列化版本号与从流中读取的类描述符的版本号匹配。可以通过显式地声明serialVersionUID来确保序列化版本号的一致性。
package cn.juwatech.serialization; import java.io.*; public class InvalidClassExceptionExample { private static final long serialVersionUID = 1L; public static void main(String[] args) { try { // Serialization FileOutputStream fileOut = new FileOutputStream("data.ser"); ObjectOutputStream out = new ObjectOutputStream(fileOut); MyClass myObject = new MyClass(); out.writeObject(myObject); out.close(); fileOut.close(); // Deserialization FileInputStream fileIn = new FileInputStream("data.ser"); ObjectInputStream in = new ObjectInputStream(fileIn); MyClass newObj = (MyClass) in.readObject(); in.close(); fileIn.close(); System.out.println("Deserialized Object: " + newObj); } catch (IOException | ClassNotFoundException e) { e.printStackTrace(); } } } class MyClass implements Serializable { private static final long serialVersionUID = 1L; // Class members and methods }
2. 自定义序列化和反序列化
通过自定义序列化和反序列化过程，可以更加灵活地控制对象的序列化和反序列化操作，从而避免InvalidClassException异常的发生。
package cn.juwatech.serialization; import java.io.*; public class CustomSerializationExample { public static void main(String[] args) { try { // Serialization FileOutputStream fileOut = new FileOutputStream("data.ser"); ObjectOutputStream out = new ObjectOutputStream(fileOut); MyClass myObject = new MyClass(); myObject.writeExternal(out); out.close(); fileOut.close(); // Deserialization FileInputStream fileIn = new FileInputStream("data.ser"); ObjectInputStream in = new ObjectInputStream(fileIn); MyClass newObj = new MyClass(); newObj.readExternal(in); in.close(); fileIn.close(); System.out.println("Deserialized Object: " + newObj); } catch (IOException e) { e.printStackTrace(); } } } class MyClass implements Externalizable { // Class members and methods @Override public void writeExternal(ObjectOutput out) throws IOException { // Custom serialization logic } @Override public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException { // Custom deserialization logic } }
3. 使用ObjectInputStream.resolveClass方法
如果在反序列化过程中遇到InvalidClassException异常，可以考虑在ObjectInputStream中重写resolveClass方法，以提供自定义的类解析逻辑。
package cn.juwatech.serialization; import java.io.*; public class ResolveClassExample { public static void main(String[] args) { try { // Deserialization FileInputStream fileIn = new FileInputStream("data.ser"); ObjectInputStream in = new ObjectInputStream(fileIn) { @Override protected Class<?> resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException { // Custom class resolution logic return super.resolveClass(desc); } }; MyClass newObj = (MyClass) in.readObject(); in.close(); fileIn.close(); System.out.println("Deserialized Object: " + newObj); } catch (IOException | ClassNotFoundException e) { e.printStackTrace(); } } }
