下面列出了java.util.function.Function#andThen ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
@Test
public void composeResourceLookupFunction() throws Exception {
ClassPathResource defaultResource = new ClassPathResource("response.txt", getClass());
Function<ServerRequest, Optional<Resource>> lookupFunction =
new PathResourceLookupFunction("/resources/**",
new ClassPathResource("org/springframework/web/servlet/function/"));
Function<ServerRequest, Optional<Resource>> customLookupFunction =
lookupFunction.andThen((Optional<Resource> optionalResource) -> {
if (optionalResource.isPresent()) {
return optionalResource;
}
else {
return Optional.of(defaultResource);
}
});
MockHttpServletRequest servletRequest = new MockHttpServletRequest("GET", "/resources/foo");
ServerRequest request = new DefaultServerRequest(servletRequest, Collections.emptyList());
Optional<Resource> result = customLookupFunction.apply(request);
assertTrue(result.isPresent());
assertEquals(defaultResource.getFile(), result.get().getFile());
}
protected JsonNode loadConfiguration(Map<String, String> properties) {
// hopefully sharing the mapper between parsers is safe... Does it
// change the state during parse?
ObjectMapper textToJsonMapper = jacksonService.newObjectMapper();
Map<ParserType, Function<InputStream, Optional<JsonNode>>> parsers = new EnumMap<>(ParserType.class);
parsers.put(ParserType.YAML, new JsonNodeYamlParser(textToJsonMapper));
parsers.put(ParserType.JSON, new JsonNodeJsonParser(textToJsonMapper));
Function<URL, Optional<JsonNode>> parser = new MultiFormatJsonNodeParser(parsers, bootLogger);
BinaryOperator<JsonNode> singleConfigMerger = new InPlaceLeftHandMerger(bootLogger);
Function<JsonNode, JsonNode> overrider = andCliOptionOverrider(identity(), parser, singleConfigMerger);
if (!properties.isEmpty()) {
overrider = overrider.andThen(new InPlaceMapOverrider(properties));
}
return JsonNodeConfigurationBuilder.builder()
.parser(parser)
.merger(singleConfigMerger)
.resources(configurationSource)
.overrider(overrider)
.build();
}
/**
* Add or replace a named scheduling {@link Function decorator}. With subsequent calls
* to this method, the onScheduleHook hook can be a composite of several sub-hooks, each
* with a different key.
* <p>
* The sub-hook is a {@link Function} taking the scheduled {@link Runnable}.
* It returns the decorated {@link Runnable}.
*
* @param key the key under which to set up the onScheduleHook sub-hook
* @param decorator the {@link Runnable} decorator to add (or replace, if key is already present)
* @see #resetOnScheduleHook(String)
* @see #resetOnScheduleHooks()
*/
public static void onScheduleHook(String key, Function<Runnable, Runnable> decorator) {
synchronized (onScheduleHooks) {
onScheduleHooks.put(key, decorator);
Function<Runnable, Runnable> newHook = null;
for (Function<Runnable, Runnable> function : onScheduleHooks.values()) {
if (newHook == null) {
newHook = function;
}
else {
newHook = newHook.andThen(function);
}
}
onScheduleHook = newHook;
}
}
private static void compose2() {
//Function<Integer, Double> multiplyBy30 = i -> i * 30d;
Function<Integer, Double> multiplyBy30 = createMultiplyBy(30d);
System.out.println(multiplyBy30.apply(1)); //prints: 30
//Function<Double,Double> subtract7 = d-> d - 7.;
Function<Double,Double> subtract7 = createSubtract(7.0);
System.out.println(subtract7.apply(10.0)); //prints: 3.0
Function<Integer, Double> multiplyBy30AndSubtract7 = subtract7.compose(multiplyBy30);
System.out.println(multiplyBy30AndSubtract7.apply(1)); //prints: 23.0
multiplyBy30AndSubtract7 = multiplyBy30.andThen(subtract7);
System.out.println(multiplyBy30AndSubtract7.apply(1)); //prints: 23.0
Function<Integer, Double> multiplyBy30Subtract7Twice = subtract7.compose(multiplyBy30).andThen(subtract7);
System.out.println(multiplyBy30Subtract7Twice.apply(1)); //prints: 16
}
@Test
public void composeResourceLookupFunction() throws Exception {
ClassPathResource defaultResource = new ClassPathResource("response.txt", getClass());
Function<ServerRequest, Mono<Resource>> lookupFunction =
new PathResourceLookupFunction("/resources/**",
new ClassPathResource("org/springframework/web/reactive/function/server/"));
Function<ServerRequest, Mono<Resource>> customLookupFunction =
lookupFunction.andThen(resourceMono -> resourceMono
.switchIfEmpty(Mono.just(defaultResource)));
MockServerRequest request = MockServerRequest.builder()
.uri(new URI("http://localhost/resources/foo"))
.build();
Mono<Resource> result = customLookupFunction.apply(request);
StepVerifier.create(result)
.expectNextMatches(resource -> {
try {
return defaultResource.getFile().equals(resource.getFile());
}
catch (IOException ex) {
return false;
}
})
.expectComplete()
.verify();
}
@Override
public <T> Higher<Higher<either, L>, T> handleErrorWith(Function<? super L, ? extends Higher<Higher<either, L>, ? extends T>> fn, Higher<Higher<either, L>, T> ds) {
Function<? super L, ? extends Either<L, T>> fn2 = fn.andThen(s -> {
Higher<Higher<either, L>, T> x = (Higher<Higher<either, L>, T>) s;
Either<L, T> r = narrowK(x);
return r;
});
return narrowK(ds).flatMapLeftToRight(fn2);
}
@Nullable
private static <T> Function<Subscriber<? super T>, Subscriber<? super T>>
andThen(@Nullable final Function<Subscriber<? super T>, Subscriber<? super T>> first,
@Nullable final Function<Subscriber<? super T>, Subscriber<? super T>> second) {
if (first == null) {
return second;
}
if (second == null) {
return first;
}
return first.andThen(second);
}
@Nullable
private static Function<Subscriber, Subscriber>
andThen(@Nullable final Function<Subscriber, Subscriber> first,
@Nullable final Function<Subscriber, Subscriber> second) {
if (first == null) {
return second;
}
if (second == null) {
return first;
}
return first.andThen(second);
}
@Override
public <T> Higher<Higher<either, L>, T> handleErrorWith(Function<? super L, ? extends Higher<Higher<either, L>, ? extends T>> fn, Higher<Higher<either, L>, T> ds) {
Function<? super L, ? extends Either<L, T>> fn2 = fn.andThen(s -> {
Higher<Higher<either, L>, T> x = (Higher<Higher<either, L>, T>)s;
Either<L, T> r = narrowK(x);
return r;
});
return narrowK(ds).flatMapLeftToRight(fn2);
}
private static void function(){
Function<Integer, Double> multiplyByTen = i -> i * 10.0;
System.out.println(multiplyByTen.apply(1)); //prints: 10.0
Supplier<Integer> supply7 = () -> 7;
Function<Integer, Double> multiplyByFive = i -> i * 5.0;
Consumer<String> printResult = printWithPrefixAndPostfix("Result: ", " Great!");
printResult.accept(multiplyByFive.apply(supply7.get()).toString()); //prints: Result: 35.0 Great!
Function<Double, Long> divideByTwo = d -> Double.valueOf(d / 2.).longValue();
Function<Long, String> incrementAndCreateString = l -> String.valueOf(l + 1);
Function<Double, String> divideByTwoIncrementAndCreateString = divideByTwo.andThen(incrementAndCreateString);
printResult.accept(divideByTwoIncrementAndCreateString.apply(4.)); //prints: Result: 3 Great!
divideByTwoIncrementAndCreateString = incrementAndCreateString.compose(divideByTwo);
printResult.accept(divideByTwoIncrementAndCreateString.apply(4.)); //prints: Result: 3 Great!
Function<Double, Double> multiplyByTwo = d -> d * 2.0;
System.out.println(multiplyByTwo.apply(2.)); //prints: 4.0
Function<Double, Long> subtract7 = d -> Math.round(d - 7);
System.out.println(subtract7.apply(11.0)); //prints: 4
long r = multiplyByTwo.andThen(subtract7).apply(2.);
System.out.println(r); //prints: -3
multiplyByTwo = Function.identity();
System.out.println(multiplyByTwo.apply(2.)); //prints: 2.0
r = multiplyByTwo.andThen(subtract7).apply(2.);
System.out.println(r); //prints: -5
}
private static QueryParameterSetter createSetter(Function<Object[], Object> valueExtractor, StringQuery.ParameterBinding binding,
@Nullable JpaParameters.JpaParameter parameter) {
TemporalType temporalType = parameter != null && parameter.isTemporalParameter() //
? parameter.getRequiredTemporalType() //
: null;
return new QueryParameterSetter.NamedOrIndexedQueryParameterSetter(valueExtractor.andThen(binding::prepare),
ParameterImpl.of(parameter, binding), temporalType);
}
private static double objectiveFunctionSteps(StepsProfiles targetStepsProfiles, StepsProfiles simulationStepsProfiles, StringBuilder summaryBuilder) {
Map<String, Function<StepActionProfile, Double>> statExtractor = new HashMap<>();
Function<StepActionProfile, Integer> getCount = StepActionProfile::getCount;
Function<StepActionProfile, Double> getCountDouble = getCount.andThen(Integer::doubleValue);
statExtractor.put("Average amount", StepActionProfile::getAvgAmount);
statExtractor.put("Std amount", StepActionProfile::getStdAmount);
statExtractor.put("Count", getCountDouble);
double totalNRMSE = 0;
summaryBuilder.append(SEPARATOR);
summaryBuilder.append(Output.EOL_CHAR);
for (String estimator: statExtractor.keySet()) {
Map<String, ArrayList<Double>> targetSeries = targetStepsProfiles.computeSeries(statExtractor.get(estimator));
Map<String, ArrayList<Double>> simulationSeries = simulationStepsProfiles.computeSeries(statExtractor.get(estimator));
for (String action : ActionTypes.getActions()) {
ArrayList<Double> unitTarget = targetSeries.get(action);
ArrayList<Double> unitSimulation = simulationSeries.get(action);
double NRMSE = computeNRMSE(unitTarget, unitSimulation);
ArrayList<String> errorLine = new ArrayList<>();
errorLine.add(estimator);
errorLine.add(action);
errorLine.add(Output.fastFormatDouble(Output.PRECISION_OUTPUT, NRMSE));
buildLineTable(errorLine, summaryBuilder);
totalNRMSE += NRMSE;
}
summaryBuilder.append(SEPARATOR);
summaryBuilder.append(Output.EOL_CHAR);
}
return totalNRMSE;
}
@Nullable
@SuppressWarnings("unchecked")
static Function<Publisher, Publisher> createOrUpdateOpHook(Collection<Function<? super Publisher<Object>, ? extends Publisher<Object>>> hooks) {
Function<Publisher, Publisher> composite = null;
for (Function<? super Publisher<Object>, ? extends Publisher<Object>> function : hooks) {
Function<? super Publisher, ? extends Publisher> op = (Function<? super Publisher, ? extends Publisher>) function;
if (composite != null) {
composite = composite.andThen(op);
}
else {
composite = (Function<Publisher, Publisher>) op;
}
}
return composite;
}
private Function<JsonNode, JsonNode> andCliOptionOverrider(
Function<JsonNode, JsonNode> overrider,
Function<URL, Optional<JsonNode>> parser,
BinaryOperator<JsonNode> singleConfigMerger) {
if (optionMetadata.isEmpty()) {
return overrider;
}
List<OptionSpec<?>> detectedOptions = cli.detectedOptions();
if (detectedOptions.isEmpty()) {
return overrider;
}
for (OptionSpec<?> cliOpt : detectedOptions) {
OptionMetadata omd = findMetadata(cliOpt);
if (omd == null) {
continue;
}
// config decorators are loaded first, and then can be overridden from options...
for (OptionRefWithConfig decorator : optionDecorators) {
if (decorator.getOptionName().equals(omd.getName())) {
overrider = overrider.andThen(new InPlaceResourceOverrider(decorator.getConfigResource().getUrl(),
parser, singleConfigMerger));
}
}
for (OptionRefWithConfigPath pathDecorator : optionPathDecorators) {
if (pathDecorator.getOptionName().equals(omd.getName())) {
String cliValue = cli.optionString(omd.getName());
overrider = overrider.andThen(new InPlaceMapOverrider(
singletonMap(pathDecorator.getConfigPath(), cliValue)
));
}
}
}
return overrider;
}
static ResourceDefinition getAuthenticationContextDefinition() {
AttributeDefinition[] attributes = new AttributeDefinition[] { CONTEXT_EXTENDS, MATCH_RULES };
TrivialAddHandler<AuthenticationContext> add = new TrivialAddHandler<AuthenticationContext>(AuthenticationContext.class, attributes, AUTHENTICATION_CONTEXT_RUNTIME_CAPABILITY) {
@Override
protected ValueSupplier<AuthenticationContext> getValueSupplier(ServiceBuilder<AuthenticationContext> serviceBuilder, OperationContext context, ModelNode model)
throws OperationFailedException {
String parent = CONTEXT_EXTENDS.resolveModelAttribute(context, model).asStringOrNull();
Supplier<AuthenticationContext> parentSupplier;
if (parent != null) {
InjectedValue<AuthenticationContext> parentInjector = new InjectedValue<>();
serviceBuilder.addDependency(context.getCapabilityServiceName(
RuntimeCapability.buildDynamicCapabilityName(AUTHENTICATION_CONTEXT_CAPABILITY, parent), AuthenticationContext.class),
AuthenticationContext.class, parentInjector);
parentSupplier = parentInjector::getValue;
} else {
parentSupplier = AuthenticationContext::empty;
}
Function<AuthenticationContext, AuthenticationContext> authContext = Function.identity();
if (model.hasDefined(ElytronDescriptionConstants.MATCH_RULES)) {
List<ModelNode> nodes = model.require(ElytronDescriptionConstants.MATCH_RULES).asList();
for (ModelNode current : nodes) {
String authenticationConfiguration = AUTHENTICATION_CONFIGURATION.resolveModelAttribute(context, current).asStringOrNull();
String sslContext = SSL_CONTEXT.resolveModelAttribute(context, current).asStringOrNull();
if (authenticationConfiguration == null && sslContext == null) {
continue;
}
Function<MatchRule, MatchRule> matchRule = ignored -> MatchRule.ALL;
String abstractType = MATCH_ABSTRACT_TYPE.resolveModelAttribute(context, current).asStringOrNull();
String abstractTypeAuthority = MATCH_ABSTRACT_TYPE_AUTHORITY.resolveModelAttribute(context, current).asStringOrNull();
matchRule = abstractType != null || abstractTypeAuthority != null ? matchRule.andThen(m -> m.matchAbstractType(abstractType, abstractTypeAuthority)) : matchRule;
ModelNode host = MATCH_HOST.resolveModelAttribute(context, current);
matchRule = host.isDefined() ? matchRule.andThen(m -> m.matchHost(host.asString())) : matchRule;
ModelNode localSecurityDomain = MATCH_LOCAL_SECURITY_DOMAIN.resolveModelAttribute(context, current);
matchRule = localSecurityDomain.isDefined() ? matchRule.andThen(m -> m.matchLocalSecurityDomain(localSecurityDomain.asString())) : matchRule;
ModelNode matchNoUser = MATCH_NO_USER.resolveModelAttribute(context, current);
matchRule = matchNoUser.asBoolean() ? matchRule.andThen(m -> m.matchNoUser()) : matchRule;
ModelNode path = MATCH_PATH.resolveModelAttribute(context, current);
matchRule = path.isDefined() ? matchRule.andThen(m -> m.matchPath(path.asString())) : matchRule;
ModelNode port = MATCH_PORT.resolveModelAttribute(context, current);
matchRule = port.isDefined() ? matchRule.andThen(m -> m.matchPort(port.asInt())) : matchRule;
ModelNode protocol = MATCH_PROTOCOL.resolveModelAttribute(context, current);
matchRule = protocol.isDefined() ? matchRule.andThen(m -> m.matchProtocol(protocol.asString())) : matchRule;
ModelNode urn = MATCH_URN.resolveModelAttribute(context, current);
matchRule = urn.isDefined() ? matchRule.andThen(m -> m.matchUrnName(urn.asString())) : matchRule;
ModelNode user = MATCH_USER.resolveModelAttribute(context, current);
matchRule = user.isDefined() ? matchRule.andThen(m -> m.matchUser(user.asString())) : matchRule;
final Function<MatchRule, MatchRule> finalMatchRule = matchRule;
Supplier<MatchRule> matchRuleSuppler = new OneTimeSupplier<>(() -> finalMatchRule.apply(null));
if (authenticationConfiguration != null) {
InjectedValue<AuthenticationConfiguration> authenticationConfigurationInjector = new InjectedValue<>();
serviceBuilder.addDependency(context.getCapabilityServiceName(
RuntimeCapability.buildDynamicCapabilityName(AUTHENTICATION_CONFIGURATION_CAPABILITY, authenticationConfiguration), AuthenticationConfiguration.class),
AuthenticationConfiguration.class, authenticationConfigurationInjector);
authContext = authContext.andThen(a -> a.with(matchRuleSuppler.get(), authenticationConfigurationInjector.getValue()));
}
if (sslContext != null) {
InjectedValue<SSLContext> sslContextInjector = new InjectedValue<>();
serviceBuilder.addDependency(context.getCapabilityServiceName(
RuntimeCapability.buildDynamicCapabilityName(SSL_CONTEXT_CAPABILITY, sslContext), SSLContext.class),
SSLContext.class, sslContextInjector);
authContext = authContext.andThen(a -> a.withSsl(matchRuleSuppler.get(), sslContextInjector::getValue));
}
}
}
final Function<AuthenticationContext, AuthenticationContext> finalContext = authContext;
return () -> finalContext.apply(parentSupplier.get());
}
};
return new TrivialResourceDefinition(ElytronDescriptionConstants.AUTHENTICATION_CONTEXT, add, attributes,
AUTHENTICATION_CONTEXT_RUNTIME_CAPABILITY);
}
public List<Schema> getSchemas() {
Function<Row, String> rowToName = r -> r.getValue(0, new StringValueFactory());
Function<Row, Schema> rowToSchema = rowToName.andThen(n -> new SchemaImpl(this.session, this, n));
return this.session.query(this.xbuilder.buildSqlStatement("select schema_name from information_schema.schemata"), null, rowToSchema,
Collectors.toList());
}
<E extends PortfolioEvent> void setEventHandlerChangingState(Class<E> event, Function<E, PortfolioState> handler) {
Function<E, Behavior> stateHandler = handler.andThen(this::behaviourForState);
builder.setEventHandlerChangingBehavior(event, stateHandler);
}
protected <U> Collector<X, ?, Map<Chain<T>, U>> collector(Function<X, U> finisher) {
Function<Entry<Chain<T>, X>, X> valueFunction = Entry::getValue;
Function<Entry<Chain<T>, X>, U> finish = valueFunction.andThen(finisher);
Function<X, Stream<Entry<Chain<T>, X>>> toIdentifierChain = this::toIdentifierChain;
return flatMapping(toIdentifierChain, toMap(Entry::getKey, finish));
}
public static void main(String[] args) {
Function<Integer,Integer> f1 = it -> { return it + 1; };
Function<Integer,Integer> f2 = it -> { return it - 10; };
Function<Integer,Integer> f4 = f1.andThen(f2);
int ret = f4.apply(0);
System.out.println(ret);
}
/**
* Wraps {@code function} that returns {@code Stream<T>} to one that returns
* {@code Stream<Maybe<T, E>>} with exceptions of type {@code E} wrapped.
*
* <p>Useful to be passed to {@link Stream#flatMap}.
*
* <p>Unchecked exceptions will be immediately propagated without being wrapped.
*/
public static <F, T, E extends Throwable> Function<F, Stream<Maybe<T, E>>> maybeStream(
CheckedFunction<? super F, ? extends Stream<? extends T>, E> function) {
Function<F, Maybe<Stream<? extends T>, E>> wrapped = maybe(function);
return wrapped.andThen(Maybe::maybeStream);
}