import org.apache.cassandra.transport.ServerError; //导入依赖的package包/类
public static ErrorMessage fromException(Throwable e)
{
    int streamId = 0;
    if (e instanceof WrappedException)
    {
        streamId = ((WrappedException)e).streamId;
        e = e.getCause();
    }

    if (e instanceof TransportException)
        return new ErrorMessage((TransportException)e, streamId);

    // Unexpected exception
    logger.error("Unexpected exception during request", e);
    return new ErrorMessage(new ServerError(e), streamId);
}
 

import org.apache.cassandra.transport.ServerError; //导入依赖的package包/类
/**
 * @param e the exception
 * @param unexpectedExceptionHandler a callback for handling unexpected exceptions. If null, or if this
 *                                   returns false, the error is logged at ERROR level via sl4fj
 */
public static ErrorMessage fromException(Throwable e, Predicate<Throwable> unexpectedExceptionHandler)
{
    int streamId = 0;
    if (e instanceof WrappedException)
    {
        streamId = ((WrappedException)e).streamId;
        e = e.getCause();
    }

    if (e instanceof TransportException)
        return new ErrorMessage((TransportException)e, streamId);

    // Unexpected exception
    if (unexpectedExceptionHandler == null || !unexpectedExceptionHandler.apply(e))
        logger.error("Unexpected exception during request", e);

    return new ErrorMessage(new ServerError(e), streamId);
}
 

import org.apache.cassandra.transport.ServerError; //导入依赖的package包/类
/**
 * @param e the exception
 * @param unexpectedExceptionHandler a callback for handling unexpected exceptions. If null, or if this
 *                                   returns false, the error is logged at ERROR level via sl4fj
 */
public static ErrorMessage fromException(Throwable e, Predicate<Throwable> unexpectedExceptionHandler)
{
    int streamId = 0;

    // Netty will wrap exceptions during decoding in a CodecException. If the cause was one of our ProtocolExceptions
    // or some other internal exception, extract that and use it.
    if (e instanceof CodecException)
    {
        Throwable cause = e.getCause();
        if (cause != null && cause instanceof WrappedException)
        {
            streamId = ((WrappedException)cause).streamId;
            e = cause.getCause();
        }
    }
    else if (e instanceof WrappedException)
    {
        streamId = ((WrappedException)e).streamId;
        e = e.getCause();
    }

    if (e instanceof TransportException)
        return new ErrorMessage((TransportException)e, streamId);

    // Unexpected exception
    if (unexpectedExceptionHandler == null || !unexpectedExceptionHandler.apply(e))
        logger.error("Unexpected exception during request", e);

    return new ErrorMessage(new ServerError(e), streamId);
}