can TextWebSocketFrame be declared with static and final?

In Netty, send messages are like this:

channel.writeAndFlush(new TextWebSocketFrame("Operation Succeed"));

to run this code, nothing abnormal. so I think, argument from writeAndFlush can be extracted to a static and final variable like this:

public class LogicHandler extends SimpleUserEventChannelHandler<WebSocketServerProtocolHandler.HandshakeComplete> {
    static final TextWebSocketFrame SUCCEED = new TextWebSocketFrame("Operation Succeed");

    @Override
    protected void eventReceived(ChannelHandlerContext context, WebSocketServerProtocolHandler.HandshakeComplete arg) {
        context.channel().writeAndFlush(SUCCEED.retain()); // the client received empty content
    } 
}

to run this codes, abnormal things happen:

the client(WebSocket from Chrome browser) received the message but empty content

Are there any ideas that i can do with it?

remove the method "retain" can not solve the problem, the only way is to remove static and final keyword.

Because the underlying ByteBuf's readerIndex is updated once used. You can reuse it by reset the readerIndex, like below. But this code is thread-unsafe, it can cause problems when there are multiple connections.

public static class LogicHandler extends SimpleUserEventChannelHandler<WebSocketServerProtocolHandler.HandshakeComplete> {
    static final TextWebSocketFrame SUCCEED = new TextWebSocketFrame("Operation Succeed");

    @Override
    protected void eventReceived(ChannelHandlerContext context, WebSocketServerProtocolHandler.HandshakeComplete arg) {
        SUCCEED.content().readerIndex(0);
        context.channel().writeAndFlush(SUCCEED.retain());
    }
}

This is thread-safe

public static class LogicHandler extends SimpleUserEventChannelHandler<WebSocketServerProtocolHandler.HandshakeComplete> {
    static final TextWebSocketFrame SUCCEED = new TextWebSocketFrame("Operation Succeed");

    @Override
    protected void eventReceived(ChannelHandlerContext context, WebSocketServerProtocolHandler.HandshakeComplete arg) {
        context.channel().writeAndFlush(SUCCEED.retainedDuplicate());
    }
}