Example usage for com.google.common.base Functions compose

Introduction

In this page you can find the example usage for com.google.common.base Functions compose.

Prototype

public static <A, B, C> Function<A, C> compose(Function<B, C> g, Function<A, ? extends B> f)

Source Link

Document

Returns the composition of two functions.

Usage

From source file:org.apache.abdera2.examples.simple.Parse.java

public static void main(String[] args) throws Exception {

    Parser parser = Abdera.getInstance().getParser();

    InputStream in = Parse.class.getResourceAsStream("/simple.xml");
    Document<Feed> doc = parser.parse(in);
    Feed feed = doc.getRoot();/*w  w  w  .  java 2 s  .  co m*/

    System.out.println(feed.getTitle());
    System.out.println(feed.getTitleType());
    System.out.println(feed.getAlternateLink().getResolvedHref());
    System.out.println(feed.getUpdated());
    System.out.println(feed.getAuthor().getName());
    System.out.println(feed.getId());

    Entry entry = feed.getEntries().get(0);

    System.out.println(entry.getTitle());
    System.out.println(entry.getTitleType());
    System.out.println(entry.getAlternateLink().getHref()); // relative URI
    System.out.println(entry.getAlternateLink().getResolvedHref()); // absolute URI resolved against Base URI
    System.out.println(entry.getId());
    System.out.println(entry.getUpdated());
    System.out.println(entry.getSummary());
    System.out.println(entry.getSummaryType());

    // Selectors can be used to filter out unwanted entries
    List<Entry> entries = feed.getEntries(Selectors.updated(DateTimes.afterNow()));
    System.out.println(entries);

    // We can also use the Guava (com.google.common.*) Function interface
    in = Parse.class.getResourceAsStream("/simple.xml");
    Function<InputStream, Document<Feed>> pf = Parsers.forInputStream();
    doc = pf.apply(in);

    // Which means we can chain things together in interesting ways...
    in = Parse.class.getResourceAsStream("/simple.xml");
    pf = Parsers.forInputStream();
    WriterFunction wf = Writers.forOutputStream("activity", System.out);
    Function<InputStream, Void> f = Functions.compose(wf, pf);
    f.apply(in);
}

From source file:org.nickelproject.util.functions.FunctionUtil.java

public static <F, T> Function<ExternalReference<F>, ExternalReference<T>> externalize(
        final Function<F, T> function) {
    return Functions.compose(new PutExternal<T>(), Functions.compose(function, new GetExternal<F>()));
}

From source file:com.github.mike10004.demo.infinitescroll.ItemServlet.java

static Function<String, String> newParamMapFunction(HttpServletRequest request) {
    return Functions.compose(new Function<String[], String>() {
        @Override/*  ww w. j av a2s. c  o m*/
        public String apply(String[] input) {
            return input != null && input.length > 0 ? input[0] : null;
        }
    }, Functions.forMap(request.getParameterMap(), null));
}

From source file:edu.umn.msi.tropix.webgui.server.resource.MappedResourceAccesorFunctionUtils.java

static Function<String, ResourceAccessor> create(final Function<String, String> idFunction,
        final Function<String, ResourceAccessor> resourceAccessorFunction) {
    return Functions.compose(resourceAccessorFunction, idFunction);
}

From source file:brooklyn.util.guava.Functionals.java

/** applies f1 to the input, then the result of that is passed to f2 (note opposite semantics to {@link Functions#compose(Function, Function)} */
public static <A, B, C> Function<A, C> chain(final Function<A, ? extends B> f1, final Function<B, C> f2) {
    return Functions.compose(f2, f1);
}

From source file:com.qcadoo.commons.functional.Optionals.java

public static <F, T> Function<F, Optional<T>> lift(final Function<F, T> f) {
    Function<T, Optional<T>> lift = lift();
    return Functions.compose(lift, f);
}

From source file:com.eucalyptus.ws.protocol.RequestLoggingFilters.java

public static void register(final RequestLoggingFilter requestLoggingFilter) {
    RequestLoggingFilter current;//w  w  w.java  2s . co m
    RequestLoggingFilter chained;
    do {
        current = filter.get();
        chained = forFunction(Functions.compose(requestLoggingFilter, current));
    } while (!filter.compareAndSet(current, chained));
}

From source file:org.trancecode.io.UriFunctions.java

public static Function<String, URI> resolveString(final URI baseUri) {
    return Functions.compose(resolveUri(baseUri), createUri());
}

From source file:com.google.cloud.bigtable.hbase.adapters.DefaultReadHooks.java

public void composePreSendHook(Function<ReadRowsRequest, ReadRowsRequest> newHook) {
    preSendHook = Functions.compose(newHook, preSendHook);
}

From source file:org.nickelproject.util.reducers.ReducerUtil.java

public static Collector<Double, Double> average() {
    final Reducer<Pair<Integer, Double>> reducer = new PairReducer<Integer, Double>(new IntegerSumReducer(),
            new DoubleSumReducer());
    final Function<Pair<Double, Double>, Pair<Integer, Double>> function = PairFunction
            .of(FunctionUtil.<Double, Integer>constant(1), Functions.<Double>identity());
    final Function<Pair<Integer, Double>, Double> divide = new Function<Pair<Integer, Double>, Double>() {
        @Override//  w w w. ja v  a2  s . c  o m
        public Double apply(@Nonnull final Pair<Integer, Double> from) {
            return from.getB() / from.getA();
        }
    };
    return Collector.create(Functions.compose(function, new ToPairFunction<Double>()), reducer, divide);
}