資料庫存了一些老框架序列化的位元組碼，由於程式碼遷移到新框架，所以修改了一些類的路徑（即就是包名被修改了），導致反序列化這些位元組碼的時候拋ClassNotFound異常（如果包名一致不存在反序列化拋異常）。

byte[] dataBytes = getBytes();

ByteArrayInputStream in = new ByteArrayInputStream( dataBytes );
ObjectInputStream objIn = new ObjectInputStream( in );
objIn.readObject();  // 這裡會拋NotFoundException
 

現在可以通過重寫ObjectInputStream中方法的方式解決這個問題，程式碼如下：

新建一個類繼承ObjectInputStream， 並重寫resolveClass()方法

public class MyObjectInputStream extends ObjectInputStream
{
  private static Logger logger = LoggerFactory.getLogger( MyObjectInputStream .class );
  private static final String OLD_PACKAGE = "com.abc.test";
  private static final String NEW_PACKAGE = "com.test";
  public MyObjectInputStream ( InputStream arg0 ) throws IOException
  {
    super( arg0 );
  }
  
  @Override
  public Class< ? > resolveClass( ObjectStreamClass desc ) throws IOException, ClassNotFoundException
  {
    String name = desc.getName();
    try
    {
      if ( name.startsWith( OLD_VISION_PACKAGE ) )
      {
        name = name.replace( OLD_VISION_PACKAGE, NEW_VISION_PACKAGE );
        return Class.forName( name );
      }
    }
    catch ( ClassNotFoundException ex )
    {
      logger.warn( ex.getMessage() );
    }

    return super.resolveClass( desc );
  }
}
 

呼叫的時候替換ObjectInputStream 為這個MyObjectInputStream就行

byte[] dataBytes = getBytes();

ByteArrayInputStream in = new ByteArrayInputStream( dataBytes );
MyObjectInputStream objIn = new MyObjectInputStream( in );
objIn.readObject();