Example usage for com.google.common.collect AbstractIterator hasNext

Introduction

In this page you can find the example usage for com.google.common.collect AbstractIterator hasNext.

Prototype

@Override
    public final boolean hasNext() 

Source Link

Usage

From source file:com.ethlo.geodata.importer.GeonamesImporter.java

@Override
public CloseableIterator<Map<String, String>> iterator() throws IOException {
    final Map<Long, Long> childToParentMap = new HashMap<>();
    final Set<Long> inHierarchy = new TreeSet<>();
    new HierarchyImporter(hierarchyFile).processFile(h -> {
        childToParentMap.put(Long.parseLong(h.get("child_id")), Long.parseLong(h.get("parent_id")));
        inHierarchy.add(Long.parseLong(h.get("child_id")));
        inHierarchy.add(Long.parseLong(h.get("parent_id")));
    });/*from w  ww.  ja  v  a  2 s  .co m*/

    // Load alternate names
    final Map<Long, String> preferredNames = loadPreferredNames("EN");

    final BufferedReader reader = IoUtils.getBufferedReader(allCountriesFile);

    final AbstractIterator<Map<String, String>> actual = new AbstractIterator<Map<String, String>>() {
        @Override
        protected Map<String, String> computeNext() {
            try {
                String line;
                while ((line = reader.readLine()) != null) {
                    final Map<String, String> map = lineToMap(line, preferredNames, childToParentMap,
                            inHierarchy);
                    if (map != null) {
                        return map;
                    }
                }
                return endOfData();
            } catch (IOException exc) {
                throw new DataAccessResourceFailureException("Cannot read line from file", exc);
            }
        }
    };

    return new CloseableIterator<Map<String, String>>() {
        @Override
        public boolean hasNext() {
            return actual.hasNext();
        }

        @Override
        public Map<String, String> next() {
            return actual.next();
        }

        @Override
        public void close() {
            IOUtils.closeQuietly(reader);
        }
    };
}

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