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:io.druid.data.input.impl.prefetch.PrefetchSqlFirehoseFactory.java

@Override
public Firehose connect(InputRowParser<Map<String, Object>> firehoseParser, @Nullable File temporaryDirectory)
        throws IOException {
    if (objects == null) {
        objects = ImmutableList.copyOf(Preconditions.checkNotNull(initObjects(), "objects"));
    }/*from   www  .ja  v  a2s.c o  m*/
    if (cacheManager.isEnabled() || prefetchConfig.getMaxFetchCapacityBytes() > 0) {
        Preconditions.checkNotNull(temporaryDirectory, "temporaryDirectory");
        Preconditions.checkArgument(temporaryDirectory.exists(), "temporaryDirectory[%s] does not exist",
                temporaryDirectory);
        Preconditions.checkArgument(temporaryDirectory.isDirectory(),
                "temporaryDirectory[%s] is not a directory", temporaryDirectory);
    }

    LOG.info("Create a new firehose for [%d] queries", objects.size());

    // fetchExecutor is responsible for background data fetching
    final ExecutorService fetchExecutor = Execs.singleThreaded("firehose_fetch_%d");
    final Fetcher<T> fetcher = new SqlFetcher<>(cacheManager, objects, fetchExecutor, temporaryDirectory,
            prefetchConfig, new ObjectOpenFunction<T>() {
                @Override
                public InputStream open(T object, File outFile) throws IOException {
                    return openObjectStream(object, outFile);
                }

                @Override
                public InputStream open(T object) throws IOException {
                    final File outFile = File.createTempFile("sqlresults_", null, temporaryDirectory);
                    return openObjectStream(object, outFile);
                }
            });

    return new SqlFirehose(new Iterator<JsonIterator<Map<String, Object>>>() {
        @Override
        public boolean hasNext() {
            return fetcher.hasNext();
        }

        @Override
        public JsonIterator<Map<String, Object>> next() {
            if (!hasNext()) {
                throw new NoSuchElementException();
            }
            try {
                TypeReference<Map<String, Object>> type = new TypeReference<Map<String, Object>>() {
                };
                final OpenedObject<T> openedObject = fetcher.next();
                final InputStream stream = openedObject.getObjectStream();
                return new JsonIterator<>(type, stream, openedObject.getResourceCloser(), objectMapper);
            } catch (Exception ioe) {
                throw new RuntimeException(ioe);
            }
        }
    }, firehoseParser, () -> {
        fetchExecutor.shutdownNow();
        try {
            Preconditions.checkState(
                    fetchExecutor.awaitTermination(prefetchConfig.getFetchTimeout(), TimeUnit.MILLISECONDS));
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
            throw new ISE("Failed to shutdown fetch executor during close");
        }
    });
}

---

From source file:com.act.lcms.MzMLParser.java

public Iterator<S> getIterator(String inputFile)
        throws ParserConfigurationException, IOException, XMLStreamException {
    DocumentBuilderFactory docFactory = mkDocBuilderFactory();
    DocumentBuilder docBuilder = docFactory.newDocumentBuilder();

    final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();
    final XMLOutputFactory xmlOutputFactory = XMLOutputFactory.newInstance();

    return new Iterator<S>() {
        boolean inEntry = false;

        XMLEventReader xr = xmlInputFactory.createXMLEventReader(new FileInputStream(inputFile), "utf-8");
        // TODO: is the use of the XML version/encoding tag definitely necessary?
        StringWriter w = new StringWriter().append(XML_PREAMBLE).append("\n");
        XMLEventWriter xw = xmlOutputFactory.createXMLEventWriter(w);

        S next = null;//from  w ww  .java2s .co  m

        /* Because we're handling the XML as a stream, we can only determine whether we have another Spectrum to return
         * by attempting to parse the next one.  `this.next()` reads
         */
        private S getNextSpectrum() {
            S spectrum = null;
            if (xr == null || !xr.hasNext()) {
                return null;
            }

            try {
                while (xr.hasNext()) {
                    XMLEvent e = xr.nextEvent();
                    if (!inEntry && e.isStartElement()
                            && e.asStartElement().getName().getLocalPart().equals((SPECTRUM_OBJECT_TAG))) {
                        xw.add(e);
                        inEntry = true;
                    } else if (e.isEndElement()
                            && e.asEndElement().getName().getLocalPart().equals(SPECTRUM_OBJECT_TAG)) {
                        xw.add(e);
                        xw.flush();
                        /* TODO: the XMLOutputFactory docs don't make it clear if/how events can be written directly into a new
                         * document structure, so we incur the cost of extracting each spectrum entry, serializing it, and
                         * re-reading it into its own document so it can be handled by XPath.  Master this strange corner of the
                         * Java ecosystem and get rid of <></>his doc -> string -> doc conversion. */
                        Document doc = docBuilder.parse(new ReaderInputStream(new StringReader(w.toString())));
                        spectrum = handleSpectrumEntry(doc);
                        xw.close();
                        /* Note: this can also be accomplished with `w.getBuffer().setLength(0);`, but using a new event writer
                         * seems safer. */
                        w = new StringWriter();
                        w.append(XML_PREAMBLE).append("\n");
                        xw = xmlOutputFactory.createXMLEventWriter(w);
                        inEntry = false;
                        // Don't stop parsing if handleSpectrumEntry didn't like this spectrum document.
                        if (spectrum != null) {
                            break;
                        }
                    } else if (inEntry) {
                        // Add this element if we're in an entry
                        xw.add(e);
                    }
                }

                // We've reached the end of the document; close the reader to show that we're done.
                if (!xr.hasNext()) {
                    xr.close();
                    xr = null;
                }
            } catch (Exception e) {
                // TODO: do better.  We seem to run into this sort of thing with Iterators a lot...
                throw new RuntimeException(e);
            }

            return spectrum;
        }

        private S tryParseNext() {
            // Fail the attempt if the reader is closed.
            if (xr == null || !xr.hasNext()) {
                return null;
            }

            // No checks on whether we already have a spectrum stored: we expect the callers to do that.
            return getNextSpectrum();
        }

        @Override
        public boolean hasNext() {
            // Prime the pump if the iterator doesn't have a value stored yet.
            if (this.next == null) {
                this.next = tryParseNext();
            }

            // If we have an entry waiting, return true; otherwise read the next entry and return true if successful.
            return this.next != null;
        }

        @Override
        public S next() {
            // Prime the pump like we do in hasNext().
            if (this.next == null) {
                this.next = tryParseNext();
            }

            // Take available spectrum and return it.
            S res = this.next;
            /* Advance to the next element immediately, making next() do the heavy lifting most of the time.  Otherwise,
             * the parsing will resume on hasNext(), which seems like it ought to be a light-weight operation. */
            this.next = tryParseNext();

            return res;
        }

    };
}

---

From source file:de.tudarmstadt.lt.lm.service.UimaStringProvider.java

public Iterator<String> applySplitHeuristic(final String text, int aggressiveness) {
    if (aggressiveness >= patterns.length)
        return new Iterator<String>() {
            int i = 0;

            @Override//from   w w  w .j  a  va  2s  .c om
            public boolean hasNext() {
                return i < text.length();
            }

            @Override
            public String next() {
                int next_i = Math.min(i + 1000, text.length());
                String result = text.substring(i, next_i);
                i = next_i;
                return result;
            }

            @Override
            public void remove() {
                throw new UnsupportedOperationException("remove() is not supported");
            }
        };

    final Matcher m = patterns[aggressiveness].matcher(text);
    return new Iterator<String>() {
        int last = 0;
        boolean found = false;

        @Override
        public boolean hasNext() {
            found = m.find();
            return found || last < text.length();
        }

        @Override
        public String next() {
            int current;
            if (found)
                current = m.end() - 1;
            else
                current = text.length();
            String res = text.substring(last, current);
            last = current;
            return res;

        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException("remove() is not supported");
        }
    };

}

---

From source file:androidx.navigation.NavGraph.java

@NonNull
@Override//from   w w w  .  j av a  2 s .c o  m
public Iterator<NavDestination> iterator() {
    return new Iterator<NavDestination>() {
        private int mIndex = -1;
        private boolean mWentToNext = false;

        @Override
        public boolean hasNext() {
            return mIndex + 1 < mNodes.size();
        }

        @Override
        public NavDestination next() {
            if (!hasNext()) {
                throw new NoSuchElementException();
            }
            mWentToNext = true;
            return mNodes.valueAt(++mIndex);
        }

        @Override
        public void remove() {
            if (!mWentToNext) {
                throw new IllegalStateException("You must call next() before you can remove an element");
            }
            mNodes.valueAt(mIndex).setParent(null);
            mNodes.removeAt(mIndex);
            mIndex--;
            mWentToNext = false;
        }
    };
}

---

From source file:org.apache.hadoop.hbase.regionserver.CompoundConfiguration.java

/**
 * Add ImmutableBytesWritable map to config list. This map is generally
 * created by HTableDescriptor or HColumnDescriptor, but can be abstractly
 * used.//  www . ja va2 s  . co  m
 *
 * @param map
 *          ImmutableBytesWritable map
 * @return this, for builder pattern
 */
public CompoundConfiguration add(final Map<ImmutableBytesWritable, ImmutableBytesWritable> map) {
    freezeMutableConf();

    // put new map at the front of the list (top priority)
    this.configs.add(0, new ImmutableConfigMap() {
        Map<ImmutableBytesWritable, ImmutableBytesWritable> m = map;

        @Override
        public String get(String key) {
            ImmutableBytesWritable ibw = new ImmutableBytesWritable(Bytes.toBytes(key));
            if (!m.containsKey(ibw))
                return null;
            ImmutableBytesWritable value = m.get(ibw);
            if (value == null || value.get() == null)
                return null;
            return Bytes.toString(value.get());
        }

        @Override
        public String getRaw(String key) {
            return get(key);
        }

        @Override
        public Class<?> getClassByName(String name) throws ClassNotFoundException {
            return null;
        }

        @Override
        public int size() {
            // TODO Auto-generated method stub
            return m.size();
        }

        @Override
        public String toString() {
            return m.toString();
        }

        @Override
        public Iterator<Entry<String, String>> iterator() {
            final Iterator<Entry<ImmutableBytesWritable, ImmutableBytesWritable>> entries = m.entrySet()
                    .iterator();
            return new Iterator<Entry<String, String>>() {

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

                @Override
                public Entry<String, String> next() {
                    final Entry<ImmutableBytesWritable, ImmutableBytesWritable> e = entries.next();
                    return new Entry<String, String>() {

                        @Override
                        public String setValue(String value) {
                            throw new UnsupportedOperationException(
                                    "Cannot set value on entry from a CompoundConfiguration!");
                        }

                        @Override
                        public String getValue() {
                            ImmutableBytesWritable bytes = e.getValue();
                            // unlike regular configuration, ImmutableBytesWritableMaps can take a null value
                            if (bytes != null) {
                                return Bytes.toString(bytes.get(), bytes.getOffset(), bytes.getLength());
                            }
                            return null;
                        }

                        @Override
                        public String getKey() {
                            ImmutableBytesWritable bytes = e.getKey();
                            return Bytes.toString(bytes.get(), bytes.getOffset(), bytes.getLength());
                        }
                    };
                }

                @Override
                public void remove() {
                    throw new UnsupportedOperationException(
                            "Cannot remove an entry from a CompoundConfiguration iterator");
                }
            };

        }
    });
    return this;
}

---

From source file:com.oracle2hsqldb.dialect.GenericDialect.java

public Iterator getSequences(DataSource dataSource, String schemaName) throws SQLException {
    return new Iterator() {
        public boolean hasNext() {
            return false;
        }// w w w .j a v a  2 s  . c  o  m

        public Object next() {
            throw new NoSuchElementException("No elements at all");
        }

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

---

From source file:org.jboss.dashboard.workspace.PanelInstance.java

public Map<String, String> getTitle() {
    LocaleManager localeManager = LocaleManager.lookup();
    final String[] langs = localeManager.getPlatformAvailableLangs();
    Map<String, String> title = new AbstractMap<String, String>() {
        public Set<Entry<String, String>> entrySet() {
            return new AbstractSet<Entry<String, String>>() {
                public int size() {
                    return langs.length;
                }/*from  w  w w.j  av  a 2 s  .co m*/

                public Iterator<Map.Entry<String, String>> iterator() {
                    return new Iterator<Map.Entry<String, String>>() {
                        int i = 0;

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

                        public boolean hasNext() {
                            return i < langs.length;
                        }

                        public Map.Entry<String, String> next() {
                            i++;
                            return new Map.Entry<String, String>() {
                                int index = i - 1;

                                public String getKey() {
                                    return langs[index];
                                }

                                public String getValue() {
                                    return getParameterValue(PARAMETER_TITLE, langs[index]);
                                }

                                public String setValue(String value) {
                                    throw new UnsupportedOperationException();
                                }
                            };
                        }
                    };
                }
            };
        }
    };
    return title;
}

---

From source file:org.mycore.datamodel.ifs2.MCRStore.java

/**
 * Lists all IDs currently used in the store, in ascending or descending
 * order/*  w  w  w. ja v a  2  s  . com*/
 * 
 * @see #ASCENDING
 * @see #DESCENDING
 * 
 * @param order
 *            the order in which IDs should be returned.
 * @return all IDs currently used in the store
 */
public Iterator<Integer> listIDs(final boolean order) {
    return new Iterator<Integer>() {
        /**
         * List of files or directories in store not yet handled
         */
        List<FileObject> files = new ArrayList<FileObject>();

        /**
         * The next ID to return, when 0, all IDs have been returned
         */
        int nextID;

        /**
         * The last ID that was returned
         */
        int lastID;

        /**
         * The order in which the IDs should be returned, ascending or
         * descending
         */
        boolean order;

        @Override
        public boolean hasNext() {
            return nextID > 0;
        }

        @Override
        public Integer next() {
            if (nextID < 1) {
                throw new NoSuchElementException();
            }

            lastID = nextID;
            nextID = findNextID();
            return lastID;
        }

        @Override
        public void remove() {
            if (lastID == 0) {
                throw new IllegalStateException();
            }
            try {
                MCRStore.this.delete(lastID);
            } catch (final Exception ex) {
                throw new MCRException("Could not delete " + MCRStore.this.getID() + " " + lastID, ex);
            }
            lastID = 0;
        }

        /**
         * Initializes the enumeration and searches for the first ID to
         * return
         * 
         * @param order
         *            the return order, ascending or descending
         */
        Iterator<Integer> init(final boolean order) {
            this.order = order;
            try {
                addChildren(baseDirectory);
            } catch (final FileSystemException e) {
                e.printStackTrace();
            }
            nextID = findNextID();
            return this;
        }

        /**
         * Adds children of the given directory to the list of files to
         * handle next. Depending on the return sort order, ascending or
         * descending file name order is used.
         * 
         * @param dir
         *            the directory thats children should be added
         * @throws FileSystemException 
         */
        private void addChildren(final FileObject dir) throws FileSystemException {
            if (dir.getType() == FileType.FOLDER) {
                final FileObject[] children = dir.getChildren();
                Arrays.sort(children, new MCRFileObjectComparator());

                for (int i = 0; i < children.length; i++) {
                    files.add(order ? i : 0, children[i]);
                }
            }
        }

        /**
         * Finds the next ID used in the store.
         * 
         * @return the next ID, or 0 if there is no other ID any more
         */
        private int findNextID() {
            if (files.isEmpty()) {
                return 0;
            }

            final FileObject first = files.remove(0);
            // checks basename length against prefix (projectId_typeId), file suffix (.xml) and configured id length
            // if they match it should be a parseable id
            if (first.getName().getBaseName().length() == idLength + prefix.length() + suffix.length()) {
                return MCRStore.this.slot2id(first.getName().getBaseName());
            }

            try {
                addChildren(first);
            } catch (final FileSystemException e) {
                e.printStackTrace();
            }
            return findNextID();
        }
    }.init(order);
}

---

From source file:org.paxml.table.csv.CsvTable.java

@Override
protected Iterator<IRow> getAllRows() {
    readRow();//from  ww  w. j  a  va 2 s .  c o m
    return new Iterator<IRow>() {

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

        @Override
        public IRow next() {
            CsvRow r = new CsvRow(CsvTable.this);
            readRow();
            return r;
        }

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

    };

}

---

From source file:org.apache.hadoop.yarn.server.api.records.impl.pb.NodeStatusPBImpl.java

private synchronized void addSqueezedContainersToProto() {
    maybeInitBuilder();/*ww  w.  jav a2 s.c  om*/
    builder.clearSqueezedContainers();
    if (squeezedContainers == null)
        return;
    Iterable<ContainerSqueezeUnitProto> iterable = new Iterable<ContainerSqueezeUnitProto>() {
        @Override
        public Iterator<ContainerSqueezeUnitProto> iterator() {
            return new Iterator<ContainerSqueezeUnitProto>() {

                Iterator<ContainerSqueezeUnit> iter = squeezedContainers.iterator();

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

                @Override
                public ContainerSqueezeUnitProto next() {
                    return convertToProtoFormat(iter.next());
                }

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

                }
            };

        }
    };
    builder.addAllSqueezedContainers(iterable);
}

---

• «
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10
• 11
• 12
• 13
• 14
• 15
• 16
• 17
• 18
• 19
• 20
• 21
• 22
• 23
• 24
• 25
• 26
• 27
• 28
• 29
• 30
• 31
• 32
• 33
• 34
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• 42
• 43
• 44
• 45
• 46
• 47
• 48
• 49
• 50
• »