Example usage for java.util Collections emptyMap

Introduction

In this page you can find the example usage for java.util Collections emptyMap.

Prototype

@SuppressWarnings("unchecked")
public static final <K, V> Map<K, V> emptyMap()

Source Link

Document

Returns an empty map (immutable).

Usage

From source file:edu.cornell.mannlib.vitro.webapp.edit.n3editing.VTwo.fields.SelectListGeneratorVTwo.java

public static Map<String, String> getOptions(EditConfigurationVTwo editConfig, String fieldName,
        WebappDaoFactory wDaoFact) {//from   www.j  av a  2 s. com

    if (editConfig == null) {
        log.error("fieldToSelectItemList() must be called with a non-null EditConfigurationVTwo ");
        return Collections.emptyMap();
    }
    if (fieldName == null) {
        log.error("fieldToSelectItemList() must be called with a non-null fieldName");
        return Collections.emptyMap();
    }

    FieldVTwo field = editConfig.getField(fieldName);
    if (field == null) {
        log.error("no field \"" + fieldName + "\" found from editConfig.");
        return Collections.emptyMap();
    }

    if (field.getFieldOptions() == null) {
        return Collections.emptyMap();
    }

    try {
        return field.getFieldOptions().getOptions(editConfig, fieldName, wDaoFact);
    } catch (Exception e) {
        log.error("Error runing getFieldOptionis()", e);
        return Collections.emptyMap();
    }
}

From source file:Main.java

/**
 * Functions as per {@link Collections#unmodifiableMap(Map)} with the exception that if the
 * given map is null, this method will return an unmodifiable empty map as per
 * {@link Collections#emptyMap()}./*from w  w  w .  j  av a2  s  . c  o  m*/
 * 
 * @param map the map for which an unmodifiable view is to be returned
 * @return an unmodifiable view of the specified set, or an unmodifiable empty set if the given
 *         set is null
 */
public static <K, V> Map<K, V> unmodifiableMapNullSafe(Map<? extends K, ? extends V> map) {
    if (map == null) {
        return Collections.emptyMap();
    }
    return Collections.unmodifiableMap(map);
}

From source file:Main.java

public static <K, V> Map<K, V> nullToEmpty(Map<K, V> map) {
    return map == null ? Collections.emptyMap() : map;
}

From source file:com.axibase.tsd.util.AtsdUtil.java

public static Map<String, String> toMap(String... tagNamesAndValues) {
    if (tagNamesAndValues == null || tagNamesAndValues.length == 0) {
        return Collections.emptyMap();
    }/*from   w  w w .  j  av a  2s .co m*/

    if (tagNamesAndValues.length % 2 == 1) {
        throw new IllegalArgumentException("Key without value");
    }

    Map<String, String> result = new HashMap<String, String>();
    for (int i = 0; i < tagNamesAndValues.length; i++) {
        result.put(tagNamesAndValues[i], tagNamesAndValues[++i]);
    }
    return result;
}

From source file:com.weibo.api.motan.config.ConfigUtil.java

/**
 * export fomart: protocol1:port1,protocol2:port2
 * //from w  w w.  ja v a 2 s  .  c o m
 * @param export
 * @return
 */
@SuppressWarnings("unchecked")
public static Map<String, Integer> parseExport(String export) {
    if (StringUtils.isBlank(export)) {
        return Collections.emptyMap();
    }
    Map<String, Integer> pps = new HashMap<String, Integer>();
    String[] protocolAndPorts = MotanConstants.COMMA_SPLIT_PATTERN.split(export);
    for (String pp : protocolAndPorts) {
        if (StringUtils.isBlank(pp)) {
            continue;
        }
        String[] ppDetail = pp.split(":");
        if (ppDetail.length == 2) {
            pps.put(ppDetail[0], Integer.parseInt(ppDetail[1]));
        } else if (ppDetail.length == 1) {
            if (MotanConstants.PROTOCOL_INJVM.equals(ppDetail[0])) {
                pps.put(ppDetail[0], MotanConstants.DEFAULT_INT_VALUE);
            } else {
                int port = MathUtil.parseInt(ppDetail[0], 0);
                if (port <= 0) {
                    throw new MotanServiceException("Export is malformed :" + export);
                } else {
                    pps.put(MotanConstants.PROTOCOL_MOTAN, port);
                }
            }

        } else {
            throw new MotanServiceException("Export is malformed :" + export);
        }
    }
    return pps;
}

From source file:Main.java

/**
 * Creates a new sorted map, based on the values from the given map and Comparator.
 * // w  w  w.j av  a 2 s.  c  o  m
 * @param map the map which needs to be sorted
 * @param valueComparator the Comparator
 * @return a new sorted map
 */
public static <K, V> Map<K, V> sortMapByValue(Map<K, V> map, Comparator<Entry<K, V>> valueComparator) {
    if (map == null) {
        return Collections.emptyMap();
    }

    List<Entry<K, V>> entriesList = new LinkedList<>(map.entrySet());

    // Sort based on the map's values
    Collections.sort(entriesList, valueComparator);

    Map<K, V> orderedMap = new LinkedHashMap<>(entriesList.size());
    for (Entry<K, V> entry : entriesList) {
        orderedMap.put(entry.getKey(), entry.getValue());
    }
    return orderedMap;
}

From source file:Main.java

/**
 * Returns a map of the passed node's attributes
 * @param node The nopde to get an attribute map for
 * @return a [possibly empty] map of the node's attributes
 *///from w w  w.  j av  a2 s.c  o m
public static Map<String, String> getAttributeMap(final Node node) {
    if (node == null)
        throw new IllegalArgumentException("The passed node was null");
    final NamedNodeMap nnm = node.getAttributes();
    final int size = nnm.getLength();
    if (size == 0)
        return Collections.emptyMap();
    final Map<String, String> map = new LinkedHashMap<String, String>(size);
    for (int i = 0; i < size; i++) {
        final Attr attr = (Attr) nnm.item(i);
        map.put(attr.getName(), attr.getValue());
    }
    return map;
}

From source file:Main.java

/**
 * Wraps a Map with the {@code Collections.unmodifiableMap}, but only once.
 *
 * <p>Checks the {@link Map} passed to ensure that it is not already a {@code Collections.unmodifiableMap}.
 * If the parameter is a null or empty, then it returns {@code Collections.emptyMap}.
 *
 * @param map {@link Map} to wrap with {@code Collections.unmodifiableMap}
 * @param <K> Key type//from w w  w. j av a2 s. com
 * @param <V> Value type
 * @return An unmodifiable Map
 */
public static <K, V> Map<K, V> unmodifiableMap(final Map<K, V> map) {
    if (isNotEmpty(map)) {
        if (!(exampleUnmodifiableMap.getClass().equals(map.getClass()))) {
            return Collections.unmodifiableMap(map);
        }
        return map;
    }
    return Collections.emptyMap();
}

From source file:com.linecorp.armeria.server.docs.FunctionInfo.java

static FunctionInfo of(Method method, Map<Class<?>, ? extends TBase<?, ?>> sampleRequests)
        throws ClassNotFoundException {
    return of(method, sampleRequests, null, Collections.emptyMap());
}

From source file:com.google.mr4c.util.CustomFormat.java

public static CustomFormat createInstance(String pattern) {
    Map<String, String> empty = Collections.emptyMap();
    return createInstance(pattern, empty);
}