@Override
    @NonNull
    public Mono<Void> writeWith(@NonNull final Publisher<? extends DataBuffer> body) {
        final Mono<DataBuffer> dataBufferMono = DataBufferUtils.join(body);
        return dataBufferMono.flatMap(dataBuffer -> {
            byte[] bytes = new byte[dataBuffer.readableByteCount()];
            dataBuffer.read(bytes);
            DataBufferUtils.release(dataBuffer);
            String bodyString = new String(bytes, StandardCharsets.UTF_8);
            final String convertStr = convert.apply(bodyString);
            return WebFluxResultUtils.result(this.exchange, convertStr).doFinally(signalType -> DataBufferUtils.release(dataBuffer));
        });
    }
Build and modify the response class.
shenyu-plugin/shenyu-plugin-base/src/main/java/org/apache/shenyu/plugin/base/support/ResponseDecorator.java