Example usage for java.util Iterator Iterator

Introduction

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

Prototype

Iterator

Source Link

Usage

From source file:org.apache.druid.data.input.impl.AbstractTextFilesFirehoseFactory.java

@Override
public Firehose connect(StringInputRowParser firehoseParser, File temporaryDirectory) throws IOException {
    initializeObjectsIfNeeded();//from  w  w w  .  j a va  2 s. c o m
    final Iterator<T> iterator = objects.iterator();
    return new FileIteratingFirehose(new Iterator<LineIterator>() {
        @Override
        public boolean hasNext() {
            return iterator.hasNext();
        }

        @Override
        public LineIterator next() {
            if (!hasNext()) {
                throw new NoSuchElementException();
            }
            final T object = iterator.next();
            try {
                return IOUtils.lineIterator(wrapObjectStream(object, openObjectStream(object)),
                        StandardCharsets.UTF_8);
            } catch (Exception e) {
                LOG.error(e, "Exception reading object[%s]", object);
                throw Throwables.propagate(e);
            }
        }
    }, firehoseParser);
}

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From source file:com.github.drochetti.javassist.maven.ClassnameExtractor.java

/**
 * Wrapping passed iterator (as reference) of class file names and extract full qualified class name on
 * {@link Iterator#next()}.//from w w  w  .  ja  v a 2 s . c o  m
 * <p>
 * It is possible that {@link Iterator#hasNext()} returns <code>true</code>
 * and {@link Iterator#next()} returns <code>null</code>.
 * 
 * @param parentDirectory
 * @param classFiles
 * @return iterator of full qualified class names based on passed classFiles
 *         or <code>null</code>
 * @see #extractClassNameFromFile(File, File)
 */
// DANGEROUS call by reference
public static Iterator<String> iterateClassnames(final File parentDirectory,
        final Iterator<File> classFileIterator) {
    return new Iterator<String>() {

        // @Override
        public boolean hasNext() {
            return classFileIterator == null ? false : classFileIterator.hasNext();
        }

        // @Override
        public String next() {
            final File classFile = classFileIterator.next();
            try {
                // possible returns null
                return extractClassNameFromFile(parentDirectory, classFile);
            } catch (final IOException e) {
                throw new RuntimeException(e.getMessage());
            }
        }

        // @Override
        public void remove() {
            classFileIterator.remove();
        }
    };
}

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From source file:org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo.java

static Iterable<StorageType> toStorageTypes(final Iterable<DatanodeStorageInfo> infos) {
    return new Iterable<StorageType>() {
        @Override//from w  ww .j a va2  s.c o m
        public Iterator<StorageType> iterator() {
            return new Iterator<StorageType>() {
                final Iterator<DatanodeStorageInfo> i = infos.iterator();

                @Override
                public boolean hasNext() {
                    return i.hasNext();
                }

                @Override
                public StorageType next() {
                    return i.next().getStorageType();
                }

                @Override
                public void remove() {
                    throw new UnsupportedOperationException();
                }
            };
        }
    };
}

---

From source file:no.packdrill.android.sparkledroid.lib.parse.csvtsv.CSVParse.java

@Override
public Iterator<Map<String, Cell>> iterator()
//--------------------------------
{
    return new Iterator<Map<String, Cell>>()
    //========================================
    {//from  www.  java2 s .c om
        Map<String, Cell> m = new HashMap<String, Cell>();

        @Override
        public boolean hasNext() {
            return it.hasNext();
        }

        @Override
        public Map<String, Cell> next()
        //--------------------------------
        {
            CSVRecord record = null;
            try {
                record = it.next();
                m.clear();
                for (int i = 0; i < record.size(); i++) {
                    String k = columns[i];
                    final String v = record.get(i);
                    if (v == null)
                        continue;
                    if (v.trim().startsWith("_:")) {
                        int p = v.indexOf("_:");
                        String name;
                        try {
                            name = v.substring(p + 2);
                        } catch (Exception _e) {
                            name = "";
                        }
                        Cell ri = new Cell(true, name);
                        ri.setUnparsedValue(v);
                        m.put(k, ri);
                        continue;
                    }
                    if (v.trim().toLowerCase().startsWith("missing ")) {
                        Object o = null;
                        Cell ri = new Cell("null", o);
                        ri.setUnparsedValue(v);
                        m.put(k, ri);
                        continue;
                    }
                    URI uri = null;
                    try {
                        uri = new URI(v);
                    } catch (Exception _e) {
                        uri = null;
                    }
                    if (uri != null) {
                        Cell ri = processURI(v);
                        if (ri != null) {
                            m.put(k, ri);
                            continue;
                        }
                    }
                    Cell ri = new Cell(v);
                    ri.setUnparsedValue(v);
                    m.put(k, ri);
                }
            } catch (NoSuchElementException e) {
                lastError = (record == null) ? "" : record.toString();
                lastException = e;
                Log.e(LOGTAG, lastError, e);
                return null;
            }
            return m;
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException(
                    "no.packdrill.android.SPARQLClient.parse.csvtsv.iterator.remove");
        }
    };
}

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From source file:org.jsonman.node.MapNode.java

@Override
public Iterable<Node> getChildren() {
    return new Iterable<Node>() {
        @Override//from ww w.ja va  2  s.com
        public Iterator<Node> iterator() {
            return new Iterator<Node>() {
                @Override
                public boolean hasNext() {
                    return entries.hasNext();
                }

                @Override
                public Node next() {
                    Map.Entry<String, Object> n = entries.next();
                    return NodeFactory.create(n.getValue());
                }

                @Override
                public void remove() {
                    throw new UnsupportedOperationException();
                }

                private Iterator<Map.Entry<String, Object>> entries = map.entrySet().iterator();
            };
        }
    };
}

---

From source file:no.packdrill.android.sparkledroid.lib.parse.csvtsv.TSVParse.java

@Override
public Iterator<Map<String, Cell>> iterator()
//--------------------------------
{
    return new Iterator<Map<String, Cell>>()
    //========================================
    {// w  ww .  j  a  v a2s . co  m
        Map<String, Cell> m = new HashMap<String, Cell>();

        final Pattern languagePattern = Pattern.compile("\"(.+)\"@(\\w\\w)$");

        @Override
        public boolean hasNext() {
            return it.hasNext();
        }

        @Override
        public Map<String, Cell> next()
        //--------------------------------
        {
            CSVRecord record = null;
            int p;
            try {
                record = it.next();
                m.clear();
                for (int i = 0; i < record.size(); i++) {
                    String k = columns[i];
                    String v = record.get(i);
                    if (v == null)
                        continue;
                    if (v.trim().startsWith("_:")) {
                        p = v.indexOf("_:");
                        String name;
                        try {
                            name = v.substring(p + 2);
                        } catch (Exception _e) {
                            name = "";
                        }
                        Cell ri = new Cell(true, name);
                        ri.setUnparsedValue(v);
                        m.put(k, ri);
                        continue;
                    }
                    if ((v.trim().startsWith("<")) && (v.trim().endsWith(">"))) {
                        p = v.indexOf('<');
                        int p1 = v.indexOf('>');
                        if ((p >= 0) && (p1 > 0))
                            v = v.substring(p + 1, p1);
                        URI uri = null;
                        try {
                            uri = new URI(v);
                        } catch (Exception _e) {
                            uri = null;
                        }
                        if (uri != null) {
                            Cell ri = processURI(v);
                            if (ri != null) {
                                m.put(k, ri);
                                continue;
                            }
                        }

                        Matcher patmatch = languagePattern.matcher(v);
                        if ((patmatch.matches()) && (patmatch.groupCount() > 0)) {
                            String s = patmatch.group(1);
                            String lang = null;
                            if (patmatch.groupCount() > 1)
                                lang = patmatch.group(2);
                            if ((s != null) && (lang != null)) {
                                Cell ri = new Cell(s, lang);
                                ri.setUnparsedValue(v);
                                m.put(k, ri);
                                continue;
                            }
                        }

                    }
                    Cell ri = new Cell(v);
                    ri.setUnparsedValue(v);
                    m.put(k, ri);
                }
            } catch (Exception e) {
                lastError = (record == null) ? "" : record.toString();
                lastException = e;
                Log.e(LOGTAG, lastError, e);
                return null;
            }
            return m;
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException(
                    "no.packdrill.android.SPARQLClient.parse.csvtsv.iterator.remove");
        }
    };
}

---

From source file:tools.datasync.db2db.dao.GenericJDBCDao.java

public Iterator<JSON> selectAll(final String entityName) {

    try {//from w  w  w.  j  av a 2  s . c  o m
        String query = "select * from " + entityName;
        final Connection connection = dataSource.getConnection();
        final Statement statement = connection.createStatement();
        logger.finest("selectAll() - " + query);
        final ResultSet result = statement.executeQuery(query);

        return new Iterator<JSON>() {
            boolean last = false;
            int count = 0;

            public boolean hasNext() {
                try {
                    if (last || result.isLast()) {
                        last = true;
                        logger.finest("selectAll() - end of result set after [" + count + "] records.");
                    }
                    return (!last);
                } catch (SQLException e) {
                    exceptionHandler.handle(e, Level.INFO, "result set error - hasNext().");
                    return false;
                }
            }

            public JSON next() {
                try {
                    result.next();
                    JSON json = new JSON(entityName);
                    int count = result.getMetaData().getColumnCount();
                    for (int index = 0; index < count; index++) {
                        String columnName = result.getMetaData().getColumnName(index);
                        String value = result.getNString(index);

                        json.set(columnName, value);
                    }
                    count++;
                    logger.finest("selectAll() - returning " + entityName + " - " + json);
                    return json;
                } catch (SQLException e) {
                    exceptionHandler.handle(e, Level.INFO, "result set error - next().");
                    return null;
                } finally {
                    try {
                        if (last || result.isLast()) {
                            logger.finest("selectAll() - closing resultset");
                            last = true;
                            result.close();
                            statement.close();
                            connection.close();
                        }
                    } catch (SQLException e) {
                        exceptionHandler.handle(e, Level.INFO, "error while closing result set.");
                    }
                }
            }

            public void remove() {
                //TODO: implement;
            }
        };

    } catch (SQLException e) {
        exceptionHandler.handle(e, Level.INFO, "result set error.");
        List<JSON> jsonList = new ArrayList<JSON>();
        return jsonList.iterator();
    }
}

---

From source file:Utils.java

/**
 * Treat an {@link Enumeration} as an {@link Iterable} so it can be used in an enhanced for-loop.
 * Bear in mind that the enumeration is "consumed" by the loop and so should be used only once.
 * Generally it is best to put the code which obtains the enumeration inside the loop header.
 * <div class="nonnormative">/*from  w  w  w . j  ava2  s .c o  m*/
 * <p>Example of correct usage:</p>
 * <pre>
 * ClassLoader loader = ...;
 * String name = ...;
 * for (URL resource : NbCollections.iterable(loader.{@link ClassLoader#getResources getResources}(name))) {
 *     // ...
 * }
 * </pre>
 * </div>
 * @param enumeration an enumeration
 * @return an iterable wrapper which will traverse the enumeration once
 *         ({@link Iterator#remove} is not supported)
 * @throws NullPointerException if the enumeration is null
 * @see <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6349852">Java bug #6349852</a>
 * @since org.openide.util 7.5
 */
public static <E> Iterable<E> iterable(final Enumeration<E> enumeration) {
    if (enumeration == null) {
        throw new NullPointerException();
    }
    return new Iterable<E>() {
        public Iterator<E> iterator() {
            return new Iterator<E>() {
                public boolean hasNext() {
                    return enumeration.hasMoreElements();
                }

                public E next() {
                    return enumeration.nextElement();
                }

                public void remove() {
                    throw new UnsupportedOperationException();
                }
            };
        }
    };
}

---

From source file:org.carewebframework.common.MiscUtil.java

/**
 * Returns a list iterator that produces only collection elements of the specified type.
 *
 * @param <T> Class of collection elements.
 * @param <S> Subclass of T to be used by iterator.
 * @param collection Collection to iterate.
 * @param type Type of element to return.
 * @return An iterator.//  w w w. j a  v  a  2s  . c o m
 */
public static <T, S extends T> Iterator<S> iteratorForType(Collection<T> collection, Class<S> type) {

    return new Iterator<S>() {

        Iterator<T> iter = collection.iterator();

        S next;

        boolean needsNext = true;

        @Override
        public boolean hasNext() {
            return nxt() != null;
        }

        @Override
        public S next() {
            S result = nxt();
            needsNext = true;
            return result;
        }

        @Override
        public void remove() {
            iter.remove();
        }

        @SuppressWarnings("unchecked")
        private S nxt() {
            if (needsNext) {
                next = null;
                needsNext = false;

                while (iter.hasNext()) {
                    T nxt = iter.next();

                    if (type.isInstance(nxt)) {
                        next = (S) nxt;
                        break;
                    }
                }
            }

            return next;
        }

    };
}

---

From source file:com.ikanow.aleph2.analytics.services.DeduplicationService.java

@Override
public void onObjectBatch(final Stream<Tuple2<Long, IBatchRecord>> batch, final Optional<Integer> batch_size,
        final Optional<JsonNode> grouping_key) {
    if (_deduplication_is_disabled.get()) {
        // no deduplication, generally shouldn't be here...
        //.. but if we are, make do the best we can
        batch.forEach(t2 -> _context.get().emitImmutableObject(t2._1(), t2._2().getJson(), Optional.empty(),
                Optional.empty(), Optional.empty()));
        return;/*from   w ww.  j a  va 2s  . c  om*/
    }

    // Create big query

    final Tuple3<QueryComponent<JsonNode>, List<Tuple2<JsonNode, Tuple2<Long, IBatchRecord>>>, Either<String, List<String>>> fieldinfo_dedupquery_keyfields = getDedupQuery(
            batch, _dedup_fields.get(), _db_mapper.get());

    // Get duplicate results

    final Tuple2<List<String>, Boolean> fields_include = getIncludeFields(_policy.get(), _dedup_fields.get(),
            _timestamp_field.get());

    final CompletableFuture<Iterator<JsonNode>> dedup_res = fieldinfo_dedupquery_keyfields._2().isEmpty()
            ? CompletableFuture.completedFuture(Collections.<JsonNode>emptyList().iterator())
            : _dedup_context.get().getObjectsBySpec(fieldinfo_dedupquery_keyfields._1(), fields_include._1(),
                    fields_include._2()).thenApply(cursor -> cursor.iterator());

    // Wait for it to finsh

    //(create handy results structure if so)
    final LinkedHashMap<JsonNode, LinkedList<Tuple3<Long, IBatchRecord, ObjectNode>>> mutable_obj_map = fieldinfo_dedupquery_keyfields
            ._2().stream()
            .collect(Collector.of(
                    () -> new LinkedHashMap<JsonNode, LinkedList<Tuple3<Long, IBatchRecord, ObjectNode>>>(),
                    (acc, t2) -> {
                        // (ie only the first element is added, duplicate elements are removed)
                        final Tuple3<Long, IBatchRecord, ObjectNode> t3 = Tuples._3T(t2._2()._1(), t2._2()._2(),
                                _mapper.createObjectNode());
                        acc.compute(t2._1(), (k, v) -> {
                            final LinkedList<Tuple3<Long, IBatchRecord, ObjectNode>> new_list = (null == v)
                                    ? new LinkedList<>()
                                    : v;
                            new_list.add(t3);
                            return new_list;
                        });
                    }, (map1, map2) -> {
                        map1.putAll(map2);
                        return map1;
                    }));

    //TODO (ALEPH-20): add timestamps to annotation
    //TODO (ALEPH-20): support different timestamp fields for the different buckets
    //TODO (ALEPH-20): really need to support >1 current enrichment job 
    //                 ^^(Really really longer term you should be able to decide what objects you want and what you don't  <- NOTE: don't remember what i meant here)

    final Iterator<JsonNode> cursor = dedup_res.join();

    // Handle the results

    final Stream<JsonNode> records_to_delete = Lambdas.get(() -> {
        if (isCustom(_doc_schema.get().deduplication_policy())
                || _doc_schema.get().delete_unhandled_duplicates()) {
            return Optionals.streamOf(cursor, true)
                    .collect(Collectors.groupingBy(
                            ret_obj -> getKeyFieldsAgain(ret_obj, fieldinfo_dedupquery_keyfields._3())))
                    .entrySet().stream().<JsonNode>flatMap(kv -> {

                        final Optional<JsonNode> maybe_key = kv.getKey();
                        final Optional<LinkedList<Tuple3<Long, IBatchRecord, ObjectNode>>> matching_records = maybe_key
                                .map(key -> mutable_obj_map.get(key));

                        // Stats:
                        _mutable_stats.duplicate_keys++;
                        _mutable_stats.duplicates_existing += kv.getValue().size();
                        _mutable_stats.duplicates_incoming += matching_records.map(l -> l.size()).orElse(0);

                        //DEBUG
                        //System.out.println("?? " + kv.getValue().size() + " vs " + maybe_key + " vs " + matching_records.map(x -> Integer.toString(x.size())).orElse("(no match)"));

                        return matching_records
                                .<Stream<JsonNode>>map(records -> handleDuplicateRecord(_doc_schema.get(),
                                        _custom_handler.optional().map(
                                                handler -> Tuples._2T(handler, this._custom_context.get())),
                                        _timestamp_field.get(), records, kv.getValue(), maybe_key.get(),
                                        mutable_obj_map))
                                .orElse(Stream.empty());
                    });
        } else {
            Optionals.streamOf(cursor, true).forEach(ret_obj -> {
                final Optional<JsonNode> maybe_key = getKeyFieldsAgain(ret_obj,
                        fieldinfo_dedupquery_keyfields._3());
                final Optional<LinkedList<Tuple3<Long, IBatchRecord, ObjectNode>>> matching_records = maybe_key
                        .map(key -> mutable_obj_map.get(key));

                //DEBUG
                //System.out.println("?? " + ret_obj + " vs " + maybe_key + " vs " + matching_record.map(x -> x._2().getJson().toString()).orElse("(no match)"));

                // Stats:
                _mutable_stats.duplicate_keys++;
                _mutable_stats.duplicates_existing++;
                _mutable_stats.duplicates_incoming += matching_records.map(l -> l.size()).orElse(0);

                matching_records.ifPresent(records -> handleDuplicateRecord(_doc_schema.get(),
                        _custom_handler.optional()
                                .map(handler -> Tuples._2T(handler, this._custom_context.get())),
                        _timestamp_field.get(), records, Arrays.asList(ret_obj), maybe_key.get(),
                        mutable_obj_map));
            });
            return Stream.<JsonNode>empty();
        }
    });

    final List<Object> ids = records_to_delete.map(j -> jsonToObject(j)).filter(j -> null != j)
            .collect(Collectors.toList());

    if (!ids.isEmpty()) { // fire a bulk deletion request
        mutable_uncompleted_deletes.add(
                _dedup_context.get().deleteObjectsBySpec(CrudUtils.allOf().withAny(AnnotationBean._ID, ids)));

        _mutable_stats.deleted += ids.size();

        //(quickly see if we can reduce the number of outstanding requests)
        final Iterator<CompletableFuture<Long>> it = mutable_uncompleted_deletes.iterator();
        while (it.hasNext()) {
            final CompletableFuture<Long> cf = it.next();
            if (cf.isDone()) {
                it.remove();
            } else
                break; // ie stop as soon as we hit one that isn't complete)
        }
    }

    _mutable_stats.nonduplicate_keys += mutable_obj_map.size();

    if (Optional.ofNullable(_doc_schema.get().custom_finalize_all_objects()).orElse(false)) {
        mutable_obj_map.entrySet().stream()
                .forEach(kv -> handleCustomDeduplication(
                        _custom_handler.optional()
                                .map(handler -> Tuples._2T(handler, this._custom_context.get())),
                        kv.getValue(), Collections.emptyList(), kv.getKey()));
    } else { // Just emit the last element of each grouped object set
        mutable_obj_map.values().stream().map(t -> t.peekLast())
                .forEach(t -> _context.get().emitImmutableObject(t._1(), t._2().getJson(), Optional.of(t._3()),
                        Optional.empty(), Optional.empty()));
    }
}

---

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