Example usage for java.util Optional of

Introduction

In this page you can find the example usage for java.util Optional of.

Prototype

public static <T> Optional<T> of(T value) 

Source Link

Document

Returns an Optional describing the given non- null value.

Usage

From source file:Main.java

public static void main(String[] args) {
    Optional<String> value = Optional.of("some value");
    System.out.println(value.isPresent());
    System.out.println(value.get());
}

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From source file:Main.java

public static void main(String[] args) {
    Optional<String> optional = Optional.of("bam");

    optional.isPresent(); // true
    optional.get(); // "bam"
    optional.orElse("fallback"); // "bam"

    optional.ifPresent((s) -> System.out.println(s.charAt(0))); // "b"
}

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From source file:Main.java

public static void main(String[] args) {
    String str = null;
    Optional value = Optional.of(str);
}

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From source file:Main.java

public static void main(String[] args) {
    Optional<String> optional1 = Optional.empty();
    Optional<String> optional2 = Optional.of("DEMO");

    System.out.println("optional2.get = " + optional2.get());
    System.out.println("optional1.orElse = " + optional1.orElse("Something else"));
    optional2.ifPresent(System.out::println);
    System.out.println("optional1.isPresent = " + optional1.isPresent());

}

---

From source file:Main.java

public static void main(String[] args) {

    Optional<String> value = Optional.of("some value");
    System.out.println(value.isPresent());
    System.out.println(value.get());
    String str = null;/*from ww  w.  jav a 2 s .c o m*/
    // Optional.of(str);

    Optional<Integer> o = Optional.empty();
    System.out.println(o.isPresent());
    System.out.println(o.orElse(42));

    List<Integer> results = new ArrayList<>();
    Optional<Integer> second = Optional.of(3);
    second.ifPresent(results::add); // must operate via side-effects,
                                    // unfortunately...
    System.out.println(results);

    o = Optional.empty();
    System.out.println(o.orElse(42));

    o = Optional.of(42);
    System.out.println(o.get());

    o = Optional.empty();
    o.get();
}

---

From source file:com.ikanow.aleph2.remote.es_tests.SimpleReadableCrudTest.java

public static void main(final String args[]) throws Exception {
    if (args.length < 1) {
        System.out.println("CLI: <host>");
        System.exit(-1);//from   ww  w  .  j av  a 2s.  c o m
    }

    final String temp_dir = System.getProperty("java.io.tmpdir") + File.separator;

    Config config = ConfigFactory
            .parseReader(new InputStreamReader(
                    SimpleReadableCrudTest.class.getResourceAsStream("/test_es_remote.properties")))
            .withValue("globals.local_root_dir", ConfigValueFactory.fromAnyRef(temp_dir))
            .withValue("globals.local_cached_jar_dir", ConfigValueFactory.fromAnyRef(temp_dir))
            .withValue("globals.distributed_root_dir", ConfigValueFactory.fromAnyRef(temp_dir))
            .withValue("globals.local_yarn_config_dir", ConfigValueFactory.fromAnyRef(temp_dir))
            .withValue("MongoDbManagementDbService.mongodb_connection",
                    ConfigValueFactory.fromAnyRef(args[0] + ":27017"))
            .withValue("ElasticsearchCrudService.elasticsearch_connection",
                    ConfigValueFactory.fromAnyRef(args[0] + ":9300"));

    final SimpleReadableCrudTest app = new SimpleReadableCrudTest();

    final Injector app_injector = ModuleUtils.createTestInjector(Arrays.asList(), Optional.of(config));
    app_injector.injectMembers(app);

    app.runTest();
    System.exit(0);
}

---

From source file:com.ikanow.aleph2.enrichment.utils.services.JsScriptEngineTestService.java

/** Entry point
 * @param args// w  w w . j a va2 s. c  o m
 * @throws IOException 
 */
public static void main(String[] args) throws IOException {
    if (args.length < 3) {
        System.out
                .println("ARGS: <script-file> <input-file> <output-prefix> [{[len: <LEN>], [group: <GROUP>]}]");
    }

    // STEP 1: load script file

    final String user_script = Files.toString(new File(args[0]), Charsets.UTF_8);

    // STEP 2: get a stream for the JSON file

    final InputStream io_stream = new FileInputStream(new File(args[1]));

    // STEP 3: set up control if applicable

    Optional<JsonNode> json = Optional.of("").filter(__ -> args.length > 3).map(__ -> args[3])
            .map(Lambdas.wrap_u(j -> _mapper.readTree(j)));

    // STEP 4: set up the various objects

    final DataBucketBean bucket = Mockito.mock(DataBucketBean.class);

    final JsScriptEngineService service_under_test = new JsScriptEngineService();

    final LinkedList<ObjectNode> emitted = new LinkedList<>();
    final LinkedList<JsonNode> grouped = new LinkedList<>();
    final LinkedList<JsonNode> externally_emitted = new LinkedList<>();

    final IEnrichmentModuleContext context = Mockito.mock(IEnrichmentModuleContext.class, new Answer<Void>() {
        @SuppressWarnings("unchecked")
        public Void answer(InvocationOnMock invocation) {
            try {
                Object[] args = invocation.getArguments();
                if (invocation.getMethod().getName().equals("emitMutableObject")) {
                    final Optional<JsonNode> grouping = (Optional<JsonNode>) args[3];
                    if (grouping.isPresent()) {
                        grouped.add(grouping.get());
                    }
                    emitted.add((ObjectNode) args[1]);
                } else if (invocation.getMethod().getName().equals("externalEmit")) {
                    final DataBucketBean to = (DataBucketBean) args[0];
                    final Either<JsonNode, Map<String, Object>> out = (Either<JsonNode, Map<String, Object>>) args[1];
                    externally_emitted
                            .add(((ObjectNode) out.left().value()).put("__a2_bucket", to.full_name()));
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    });

    final EnrichmentControlMetadataBean control = BeanTemplateUtils.build(EnrichmentControlMetadataBean.class)
            .with(EnrichmentControlMetadataBean::config,
                    new LinkedHashMap<String, Object>(
                            ImmutableMap.<String, Object>builder().put("script", user_script).build()))
            .done().get();

    service_under_test.onStageInitialize(context, bucket, control,
            Tuples._2T(ProcessingStage.batch, ProcessingStage.grouping), Optional.empty());

    final BeJsonParser json_parser = new BeJsonParser();

    // Run the file through

    final Stream<Tuple2<Long, IBatchRecord>> json_stream = StreamUtils
            .takeUntil(Stream.generate(() -> json_parser.getNextRecord(io_stream)), i -> null == i)
            .map(j -> Tuples._2T(0L, new BatchRecord(j)));

    service_under_test.onObjectBatch(json_stream, json.map(j -> j.get("len")).map(j -> (int) j.asLong(0L)),
            json.map(j -> j.get("group")));

    System.out.println("RESULTS: ");
    System.out.println("emitted: " + emitted.size());
    System.out.println("grouped: " + grouped.size());
    System.out.println("externally emitted: " + externally_emitted.size());
    Files.write(emitted.stream().map(j -> j.toString()).collect(Collectors.joining(";")),
            new File(args[2] + "emit.json"), Charsets.UTF_8);
    Files.write(grouped.stream().map(j -> j.toString()).collect(Collectors.joining(";")),
            new File(args[2] + "group.json"), Charsets.UTF_8);
    Files.write(externally_emitted.stream().map(j -> j.toString()).collect(Collectors.joining(";")),
            new File(args[2] + "external_emit.json"), Charsets.UTF_8);
}

---

From source file:com.arpnetworking.metrics.mad.Main.java

/**
 * Entry point for Metrics Aggregator Daemon (MAD).
 *
 * @param args the command line arguments
 *//* w ww.jav  a  2  s  .  c  om*/
public static void main(final String[] args) {
    // Global initialization
    Thread.setDefaultUncaughtExceptionHandler((thread, throwable) -> {
        System.err.println("Unhandled exception! exception: " + throwable.toString());
        throwable.printStackTrace(System.err);
    });

    Thread.currentThread().setUncaughtExceptionHandler((thread, throwable) -> LOGGER.error()
            .setMessage("Unhandled exception!").setThrowable(throwable).log());

    LOGGER.info().setMessage("Launching mad").log();

    Runtime.getRuntime().addShutdownHook(SHUTDOWN_THREAD);

    System.setProperty("org.vertx.logger-delegate-factory-class-name",
            "org.vertx.java.core.logging.impl.SLF4JLogDelegateFactory");

    // Run the tsd aggregator
    if (args.length != 1) {
        throw new RuntimeException("No configuration file specified");
    }
    LOGGER.debug().setMessage("Loading configuration").addData("file", args[0]).log();

    Optional<DynamicConfiguration> configuration = Optional.empty();
    Optional<Configurator<Main, AggregatorConfiguration>> configurator = Optional.empty();
    try {
        final File configurationFile = new File(args[0]);
        configurator = Optional.of(new Configurator<>(Main::new, AggregatorConfiguration.class));
        configuration = Optional.of(new DynamicConfiguration.Builder().setObjectMapper(OBJECT_MAPPER)
                .addSourceBuilder(getFileSourceBuilder(configurationFile))
                .addTrigger(new FileTrigger.Builder().setFile(configurationFile).build())
                .addListener(configurator.get()).build());

        configuration.get().launch();
        // Wait for application shutdown
        SHUTDOWN_SEMAPHORE.acquire();
    } catch (final InterruptedException e) {
        throw Throwables.propagate(e);
    } finally {
        if (configurator.isPresent()) {
            configurator.get().shutdown();
        }
        if (configuration.isPresent()) {
            configuration.get().shutdown();
        }
        // Notify the shutdown that we're done
        SHUTDOWN_SEMAPHORE.release();
    }
}

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From source file:com.ikanow.aleph2.data_import_manager.harvest.modules.LocalHarvestTestModule.java

/** Entry point
 * @param args - config_file source_key harvest_tech_id
 * @throws Exception //from  ww w  .  java  2  s.  c o  m
 */
public static void main(final String[] args) {
    try {
        if (args.length < 3) {
            System.out.println("CLI: config_file source_key harvest_tech_jar_path");
            System.exit(-1);
        }
        System.out.println("Running with command line: " + Arrays.toString(args));
        Config config = ConfigFactory.parseFile(new File(args[0]));

        LocalHarvestTestModule app = ModuleUtils.initializeApplication(Arrays.asList(), Optional.of(config),
                Either.left(LocalHarvestTestModule.class));
        app.start(args[1], args[2], Arrays.copyOfRange(args, 3, args.length));
    } catch (Exception e) {
        try {
            System.out.println("Got all the way to main");
            e.printStackTrace();
        } catch (Exception e2) { // the exception failed!
            System.out.println(ErrorUtils.getLongForm("Got all the way to main: {0}", e));
        }
    }
}

---

From source file:com.act.biointerpretation.l2expansion.L2ExpansionDriver.java

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

    // Build command line parser.
    Options opts = new Options();
    for (Option.Builder b : OPTION_BUILDERS) {
        opts.addOption(b.build());//from   w ww  . j  av a  2s .  c  o m
    }

    CommandLine cl = null;
    try {
        CommandLineParser parser = new DefaultParser();
        cl = parser.parse(opts, args);
    } catch (ParseException e) {
        LOGGER.error("Argument parsing failed: %s", e.getMessage());
        HELP_FORMATTER.printHelp(L2ExpansionDriver.class.getCanonicalName(), HELP_MESSAGE, opts, null, true);
        System.exit(1);
    }

    // Print help.
    if (cl.hasOption(OPTION_HELP)) {
        HELP_FORMATTER.printHelp(L2ExpansionDriver.class.getCanonicalName(), HELP_MESSAGE, opts, null, true);
        return;
    }

    // Get output files.
    String outputPath = cl.getOptionValue(OPTION_OUTPUT_PATH);
    File outputFile = new File(outputPath);
    if (outputFile.isDirectory() || outputFile.exists()) {
        LOGGER.error("Supplied output file is a directory or already exists.");
        System.exit(1);
    }
    outputFile.createNewFile();
    File inchiOutputFile = new File(outputPath + ".inchis");
    if (inchiOutputFile.isDirectory() || inchiOutputFile.exists()) {
        LOGGER.error("Supplied inchi output file is a directory or already exists.");
        System.exit(1);
    }
    inchiOutputFile.createNewFile();

    Optional<OutputStream> maybeProgressStream = Optional.empty();
    if (cl.hasOption(OPTION_PROGRESS_PATH)) {
        String progressPath = cl.getOptionValue(OPTION_PROGRESS_PATH);
        File progressFile = new File(progressPath);
        LOGGER.info("Writing incremental results to file at %s", progressFile.getAbsolutePath());
        if (progressFile.isDirectory() || progressFile.exists()) {
            LOGGER.error("Supplied progress file is a directory or already exists.");
            System.exit(1);
        }
        maybeProgressStream = Optional.of(new FileOutputStream(progressFile));
    }

    // Get metabolite list
    L2InchiCorpus inchiCorpus = getInchiCorpus(cl, OPTION_METABOLITES);
    LOGGER.info("%d substrate inchis.", inchiCorpus.getInchiList().size());

    Integer maxMass = NO_MASS_THRESHOLD;
    if (cl.hasOption(OPTION_MASS_THRESHOLD)) {
        maxMass = Integer.parseInt(cl.getOptionValue(OPTION_MASS_THRESHOLD));
        LOGGER.info("Filtering out substrates with mass more than %d daltons.", maxMass);
    }
    inchiCorpus.filterByMass(maxMass);
    LOGGER.info("%d substrate inchis that are importable as molecules.", inchiCorpus.getInchiList().size());

    PredictionGenerator generator = new AllPredictionsGenerator(new ReactionProjector());

    L2Expander expander = buildExpander(cl, inchiCorpus, generator);
    L2PredictionCorpus predictionCorpus = expander.getPredictions(maybeProgressStream);

    LOGGER.info("Done with L2 expansion. Produced %d predictions.", predictionCorpus.getCorpus().size());

    LOGGER.info("Writing corpus to file.");
    predictionCorpus.writePredictionsToJsonFile(outputFile);
    L2InchiCorpus productInchis = new L2InchiCorpus(predictionCorpus.getUniqueProductInchis());
    productInchis.writeToFile(inchiOutputFile);
    LOGGER.info("L2ExpansionDriver complete!");
}

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