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

Introduction

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

Prototype

public static Mono<DataBuffer> join(Publisher<DataBuffer> dataBuffers) 

Source Link

Document

Return a new DataBuffer composed from joining together the given dataBuffers elements.

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 a v  a2s  .  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.web.reactive.resource.AppCacheManifestTransformer.java

@Override
public Mono<Resource> transform(ServerWebExchange exchange, Resource inputResource,
        ResourceTransformerChain chain) {

    return chain.transform(exchange, inputResource).flatMap(outputResource -> {
        String name = outputResource.getFilename();
        if (!this.fileExtension.equals(StringUtils.getFilenameExtension(name))) {
            return Mono.just(outputResource);
        }/*  w w w . j av a 2  s. c o  m*/
        DataBufferFactory bufferFactory = exchange.getResponse().bufferFactory();
        Flux<DataBuffer> flux = DataBufferUtils.read(outputResource, bufferFactory, StreamUtils.BUFFER_SIZE);
        return DataBufferUtils.join(flux).flatMap(dataBuffer -> {
            CharBuffer charBuffer = DEFAULT_CHARSET.decode(dataBuffer.asByteBuffer());
            DataBufferUtils.release(dataBuffer);
            String content = charBuffer.toString();
            return transform(content, outputResource, chain, exchange);
        });
    });
}

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From source file:org.springframework.web.reactive.resource.CssLinkResourceTransformer.java

@Override
public Mono<Resource> transform(ServerWebExchange exchange, Resource inputResource,
        ResourceTransformerChain transformerChain) {

    return transformerChain.transform(exchange, inputResource).flatMap(ouptputResource -> {
        String filename = ouptputResource.getFilename();
        if (!"css".equals(StringUtils.getFilenameExtension(filename))
                || inputResource instanceof GzipResourceResolver.GzippedResource) {
            return Mono.just(ouptputResource);
        }/*from  w  w  w. j av  a 2s. c o  m*/

        if (logger.isTraceEnabled()) {
            logger.trace("Transforming resource: " + ouptputResource);
        }

        DataBufferFactory bufferFactory = exchange.getResponse().bufferFactory();
        Flux<DataBuffer> flux = DataBufferUtils.read(ouptputResource, bufferFactory, StreamUtils.BUFFER_SIZE);
        return DataBufferUtils.join(flux).flatMap(dataBuffer -> {
            CharBuffer charBuffer = DEFAULT_CHARSET.decode(dataBuffer.asByteBuffer());
            DataBufferUtils.release(dataBuffer);
            String cssContent = charBuffer.toString();
            return transformContent(cssContent, ouptputResource, transformerChain, exchange);
        });
    });
}

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