Example usage for org.springframework.core.io.buffer DataBufferUtils retain

Introduction

In this page you can find the example usage for org.springframework.core.io.buffer DataBufferUtils retain.

Prototype

@SuppressWarnings("unchecked")
public static <T extends DataBuffer> T retain(T dataBuffer) 

Source Link

Document

Retain the given data buffer, it it is a PooledDataBuffer .

Usage

From source file:org.springframework.cloud.gateway.handler.predicate.ReadBodyPredicateFactory.java

@Override
@SuppressWarnings("unchecked")
public AsyncPredicate<ServerWebExchange> applyAsync(Config config) {
    return exchange -> {
        Class inClass = config.getInClass();

        Object cachedBody = exchange.getAttribute(CACHE_REQUEST_BODY_OBJECT_KEY);
        Mono<?> modifiedBody;//from   ww w. j ava 2 s .c  o  m
        // We can only read the body from the request once, once that happens if we
        // try to read the body again an exception will be thrown. The below if/else
        // caches the body object as a request attribute in the ServerWebExchange
        // so if this filter is run more than once (due to more than one route
        // using it) we do not try to read the request body multiple times
        if (cachedBody != null) {
            try {
                boolean test = config.predicate.test(cachedBody);
                exchange.getAttributes().put(TEST_ATTRIBUTE, test);
                return Mono.just(test);
            } catch (ClassCastException e) {
                if (LOGGER.isDebugEnabled()) {
                    LOGGER.debug("Predicate test failed because class in predicate "
                            + "does not match the cached body object", e);
                }
            }
            return Mono.just(false);
        } else {
            // Join all the DataBuffers so we have a single DataBuffer for the body
            return DataBufferUtils.join(exchange.getRequest().getBody()).flatMap(dataBuffer -> {
                // Update the retain counts so we can read the body twice,
                // once to parse into an object
                // that we can test the predicate against and a second time
                // when the HTTP client sends
                // the request downstream
                // Note: if we end up reading the body twice we will run into
                // a problem, but as of right
                // now there is no good use case for doing this
                DataBufferUtils.retain(dataBuffer);
                // Make a slice for each read so each read has its own
                // read/write indexes
                Flux<DataBuffer> cachedFlux = Flux
                        .defer(() -> Flux.just(dataBuffer.slice(0, dataBuffer.readableByteCount())));

                ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(exchange.getRequest()) {
                    @Override
                    public Flux<DataBuffer> getBody() {
                        return cachedFlux;
                    }
                };
                return ServerRequest.create(exchange.mutate().request(mutatedRequest).build(), messageReaders)
                        .bodyToMono(inClass).doOnNext(objectValue -> {
                            exchange.getAttributes().put(CACHE_REQUEST_BODY_OBJECT_KEY, objectValue);
                            exchange.getAttributes().put(CACHED_REQUEST_BODY_KEY, cachedFlux);
                        }).map(objectValue -> config.predicate.test(objectValue));
            });

        }
    };
}

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From source file:org.springframework.http.codec.multipart.DefaultMultipartMessageReader.java

/**
 * Convert the given data buffer into a Part. All data up until the header separator (\r\n\r\n)
 * is passed to {@link #toHeaders(DataBuffer)}, the remaining data is considered to be the
 * body./*  w w w  .j  a  v a  2  s  .c o  m*/
 */
private static Part toPart(DataBuffer dataBuffer) {
    int readPosition = dataBuffer.readPosition();
    if (dataBuffer.readableByteCount() >= 2) {
        if (dataBuffer.getByte(readPosition) == CR && dataBuffer.getByte(readPosition + 1) == LF) {
            dataBuffer.readPosition(readPosition + 2);
        }
    }

    if (logger.isTraceEnabled()) {
        logger.trace("Part data: " + toString(dataBuffer));
    }
    int endIdx = HEADER_MATCHER.match(dataBuffer);

    HttpHeaders headers;
    DataBuffer body;
    if (endIdx > 0) {
        readPosition = dataBuffer.readPosition();
        int headersLength = endIdx + 1 - (readPosition + HEADER_BODY_SEPARATOR.length);
        DataBuffer headersBuffer = dataBuffer.retainedSlice(readPosition, headersLength);
        int bodyLength = dataBuffer.writePosition() - (1 + endIdx);
        body = dataBuffer.retainedSlice(endIdx + 1, bodyLength);
        headers = toHeaders(headersBuffer);
    } else {
        headers = new HttpHeaders();
        body = DataBufferUtils.retain(dataBuffer);
    }
    DataBufferUtils.release(dataBuffer);

    ContentDisposition cd = headers.getContentDisposition();
    MediaType contentType = headers.getContentType();
    if (StringUtils.hasLength(cd.getFilename())) {
        return new DefaultFilePart(headers, body);
    } else if (StringUtils.hasLength(cd.getName())
            && (contentType == null || MediaType.TEXT_PLAIN.isCompatibleWith(contentType))) {
        return new DefaultFormPart(headers, body);
    } else {
        return new DefaultPart(headers, body);
    }
}

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