Example usage for java.util Optional ofNullable

List of usage examples for java.util Optional ofNullable

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Introduction

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

Prototype

@SuppressWarnings("unchecked")
public static <T> Optional<T> ofNullable(T value)

Source Link

Document

Returns an Optional describing the given value, if non- null , otherwise returns an empty Optional .

Usage

From source file:com.github.ansell.shp.SHPDump.java

public static void main(String... args) throws Exception {
    final OptionParser parser = new OptionParser();

    final OptionSpec<Void> help = parser.accepts("help").forHelp();
    final OptionSpec<File> input = parser.accepts("input").withRequiredArg().ofType(File.class).required()
            .describedAs("The input SHP file");
    final OptionSpec<File> output = parser.accepts("output").withRequiredArg().ofType(File.class).required()
            .describedAs("The output directory to use for debugging files");
    final OptionSpec<String> outputPrefix = parser.accepts("prefix").withRequiredArg().ofType(String.class)
            .defaultsTo("shp-debug").describedAs("The output prefix to use for debugging files");
    final OptionSpec<File> outputMappingTemplate = parser.accepts("output-mapping").withRequiredArg()
            .ofType(File.class).describedAs("The output mapping template file if it needs to be generated.");
    final OptionSpec<Integer> resolution = parser.accepts("resolution").withRequiredArg().ofType(Integer.class)
            .defaultsTo(2048).describedAs("The output image file resolution");
    final OptionSpec<String> format = parser.accepts("format").withRequiredArg().ofType(String.class)
            .defaultsTo("png").describedAs("The output image format");
    final OptionSpec<String> removeIfEmpty = parser.accepts("remove-if-empty").withRequiredArg()
            .ofType(String.class).describedAs(
                    "The name of an attribute to remove if its value is empty before outputting the resulting shapefile. Use multiple times to specify multiple fields to check");

    OptionSet options = null;/* www.  j  a v  a 2s . com*/

    try {
        options = parser.parse(args);
    } catch (final OptionException e) {
        System.out.println(e.getMessage());
        parser.printHelpOn(System.out);
        throw e;
    }

    if (options.has(help)) {
        parser.printHelpOn(System.out);
        return;
    }

    final Path inputPath = input.value(options).toPath();
    if (!Files.exists(inputPath)) {
        throw new FileNotFoundException("Could not find input SHP file: " + inputPath.toString());
    }

    final Path outputPath = output.value(options).toPath();
    if (!Files.exists(outputPath)) {
        throw new FileNotFoundException("Output directory does not exist: " + outputPath.toString());
    }

    final Path outputMappingPath = options.has(outputMappingTemplate)
            ? outputMappingTemplate.value(options).toPath()
            : null;
    if (options.has(outputMappingTemplate) && Files.exists(outputMappingPath)) {
        throw new FileNotFoundException(
                "Output mapping template file already exists: " + outputMappingPath.toString());
    }

    final Set<String> filterFields = ConcurrentHashMap.newKeySet();
    if (options.has(removeIfEmpty)) {
        for (String nextFilterField : removeIfEmpty.values(options)) {
            System.out.println("Will filter field if empty value found: " + nextFilterField);
            filterFields.add(nextFilterField);
        }
    }

    if (!filterFields.isEmpty()) {
        System.out.println("Full set of filter fields: " + filterFields);
    }

    final String prefix = outputPrefix.value(options);

    FileDataStore store = FileDataStoreFinder.getDataStore(inputPath.toFile());

    if (store == null) {
        throw new RuntimeException("Could not read the given input as an ESRI Shapefile: "
                + inputPath.toAbsolutePath().toString());
    }

    for (String typeName : new LinkedHashSet<>(Arrays.asList(store.getTypeNames()))) {
        System.out.println("");
        System.out.println("Type: " + typeName);
        SimpleFeatureSource featureSource = store.getFeatureSource(typeName);
        SimpleFeatureType schema = featureSource.getSchema();

        Name outputSchemaName = new NameImpl(schema.getName().getNamespaceURI(),
                schema.getName().getLocalPart().replace(" ", "").replace("%20", ""));
        System.out.println("Replacing name on schema: " + schema.getName() + " with " + outputSchemaName);
        SimpleFeatureType outputSchema = SHPUtils.changeSchemaName(schema, outputSchemaName);

        List<String> attributeList = new ArrayList<>();
        for (AttributeDescriptor attribute : schema.getAttributeDescriptors()) {
            System.out.println("Attribute: " + attribute.getName().toString());
            attributeList.add(attribute.getName().toString());
        }
        CsvSchema csvSchema = CSVUtil.buildSchema(attributeList);

        SimpleFeatureCollection collection = featureSource.getFeatures();
        int featureCount = 0;
        Path nextCSVFile = outputPath.resolve(prefix + ".csv");
        Path nextSummaryCSVFile = outputPath
                .resolve(prefix + "-" + outputSchema.getTypeName() + "-Summary.csv");
        List<SimpleFeature> outputFeatureList = new CopyOnWriteArrayList<>();

        try (SimpleFeatureIterator iterator = collection.features();
                Writer bufferedWriter = Files.newBufferedWriter(nextCSVFile, StandardCharsets.UTF_8,
                        StandardOpenOption.CREATE_NEW);
                SequenceWriter csv = CSVUtil.newCSVWriter(bufferedWriter, csvSchema);) {
            List<String> nextLine = new ArrayList<>();
            while (iterator.hasNext()) {
                SimpleFeature feature = iterator.next();
                featureCount++;
                if (featureCount <= 2) {
                    System.out.println("");
                    System.out.println(feature.getIdentifier());
                } else if (featureCount % 100 == 0) {
                    System.out.print(".");
                }
                boolean filterThisFeature = false;
                for (AttributeDescriptor attribute : schema.getAttributeDescriptors()) {
                    String featureString = Optional.ofNullable(feature.getAttribute(attribute.getName()))
                            .orElse("").toString();
                    nextLine.add(featureString);
                    if (filterFields.contains(attribute.getName().toString())
                            && featureString.trim().isEmpty()) {
                        filterThisFeature = true;
                    }
                    if (featureString.length() > 100) {
                        featureString = featureString.substring(0, 100) + "...";
                    }
                    if (featureCount <= 2) {
                        System.out.print(attribute.getName() + "=");
                        System.out.println(featureString);
                    }
                }
                if (!filterThisFeature) {
                    outputFeatureList.add(SHPUtils.changeSchemaName(feature, outputSchema));
                    csv.write(nextLine);
                }
                nextLine.clear();
            }
        }
        try (Reader csvReader = Files.newBufferedReader(nextCSVFile, StandardCharsets.UTF_8);
                Writer summaryOutput = Files.newBufferedWriter(nextSummaryCSVFile, StandardCharsets.UTF_8,
                        StandardOpenOption.CREATE_NEW);
                final Writer mappingWriter = options.has(outputMappingTemplate)
                        ? Files.newBufferedWriter(outputMappingPath)
                        : NullWriter.NULL_WRITER) {
            CSVSummariser.runSummarise(csvReader, summaryOutput, mappingWriter,
                    CSVSummariser.DEFAULT_SAMPLE_COUNT, false);
        }
        if (featureCount > 100) {
            System.out.println("");
        }
        System.out.println("");
        System.out.println("Feature count: " + featureCount);

        SimpleFeatureCollection outputCollection = new ListFeatureCollection(outputSchema, outputFeatureList);
        Path outputShapefilePath = outputPath.resolve(prefix + "-" + outputSchema.getTypeName() + "-dump");
        if (!Files.exists(outputShapefilePath)) {
            Files.createDirectory(outputShapefilePath);
        }
        SHPUtils.writeShapefile(outputCollection, outputShapefilePath);

        // Create ZIP file from the contents to keep the subfiles together
        Path outputShapefileZipPath = outputPath
                .resolve(prefix + "-" + outputSchema.getTypeName() + "-dump.zip");
        try (final OutputStream out = Files.newOutputStream(outputShapefileZipPath,
                StandardOpenOption.CREATE_NEW);
                final ZipOutputStream zip = new ZipOutputStream(out, StandardCharsets.UTF_8);) {
            Files.list(outputShapefilePath).forEachOrdered(Unchecked.consumer(e -> {
                zip.putNextEntry(new ZipEntry(e.getFileName().toString()));
                Files.copy(e, zip);
                zip.closeEntry();
            }));
        }

        try (final OutputStream outputStream = Files.newOutputStream(
                outputPath.resolve(prefix + "." + format.value(options)), StandardOpenOption.CREATE_NEW);) {
            MapContent map = new MapContent();
            map.setTitle(prefix + "-" + outputSchema.getTypeName());
            Style style = SLD.createSimpleStyle(featureSource.getSchema());
            Layer layer = new FeatureLayer(new CollectionFeatureSource(outputCollection), style);
            map.addLayer(layer);
            SHPUtils.renderImage(map, outputStream, resolution.value(options), format.value(options));
        }
    }
}

From source file:Main.java

private static <T> String elementNameFrom(final Class<T> clazz) {
    return Optional.ofNullable(clazz.getAnnotation(XmlRootElement.class)).map(XmlRootElement::name)
            .orElseGet(clazz::getSimpleName);
}

From source file:Main.java

/**
 * Gets the content of an attribute.// w  w w.  j a  v a2  s .  co  m
 * For example,
 * <item attributeName="content" />
 */
public static Optional<String> getAttributeContent(Node item, String attributeName) {
    NamedNodeMap attributes = item.getAttributes();
    return Optional.ofNullable(attributes.getNamedItem(attributeName)).map(Node::getTextContent);
}

From source file:Main.java

/**
 * Gets the content of a subnode.//from  www. j av  a  2  s .  c o  m
 * For example,
 * <item>
 *     <nodeName>content</nodeName>
 * </item>
 */
public static Optional<String> getNodeContent(Node item, String nodeName) {
    if (item.getNodeType() != Node.ELEMENT_NODE) {
        return Optional.empty();
    }

    NodeList metadata = ((Element) item).getElementsByTagName(nodeName);
    if (metadata.getLength() == 1) {
        return Optional.ofNullable(metadata.item(0).getTextContent());
    } else {
        return Optional.empty();
    }
}

From source file:Main.java

public static <T> Stream<T> stream(Collection<T> collection) {
    return Optional.ofNullable(collection).orElseGet(Collections::emptyList).stream();
}

From source file:lab.mage.spring.cassandra.connector.util.TenantContextHolder.java

@Nonnull
public static Optional<String> getIdentifier() {
    return Optional.ofNullable(TenantContextHolder.THREAD_LOCAL.get());
}

From source file:alfio.util.LocaleUtil.java

public static Locale getTicketLanguage(Ticket t, HttpServletRequest request) {
    return Optional.ofNullable(t.getUserLanguage()).filter(StringUtils::isNotBlank).map(Locale::forLanguageTag)
            .orElseGet(() -> RequestContextUtils.getLocale(request));
}

From source file:Main.java

public static <T extends Comparable<? super T>> SortedSet<T> newSortedSet(Collection<? extends T> set) {
    return Optional.ofNullable(set).map(TreeSet<T>::new).orElseGet(TreeSet::new);
}

From source file:Main.java

/**
 * @param <T> the element type//from   ww  w.j  av  a  2s.co m
 * @param s   the set
 *
 * @return an <b>UNMODIFIABLE</b> Set&lt;T&gt;
 */
public static <T> Set<? extends T> unmodifiableSet(Set<? extends T> s) {
    return Optional.ofNullable(s).map(Collections::unmodifiableSet).orElseGet(Collections::emptySet);
}

From source file:Main.java

/**
 * Return the "safe" list. This method never returns a value of
 * {@code null}, if the input list is equal to {@code null}, then instead it
 * will return an empty list/* w  w  w . j a  v  a  2s .c  om*/
 *
 * @param <T> Type of list of elements
 * @param list List of elements
 * @return The input or an empty list
 */
public static <T> List<T> getSafeList(final List<T> list) {
    return Optional.ofNullable(list).orElse(Collections.<T>emptyList());
}