Example usage for org.apache.commons.collections IteratorUtils singletonIterator

Introduction

In this page you can find the example usage for org.apache.commons.collections IteratorUtils singletonIterator.

Prototype

public static ResettableIterator singletonIterator(Object object) 

Source Link

Document

Gets a singleton iterator.

Usage

From source file:com.bigdata.dastor.db.filter.SliceQueryFilter.java

public SuperColumn filterSuperColumn(SuperColumn superColumn, int gcBefore) {
    // we clone shallow, then add, under the theory that generally we're interested in a relatively small number of subcolumns.
    // this may be a poor assumption.
    SuperColumn scFiltered = superColumn.cloneMeShallow();
    Iterator<IColumn> subcolumns;
    if (reversed) {
        List<IColumn> columnsAsList = new ArrayList<IColumn>(superColumn.getSubColumns());
        subcolumns = new ReverseListIterator(columnsAsList);
    } else {//from   w w w.  jav  a2 s . com
        subcolumns = superColumn.getSubColumns().iterator();
    }

    // iterate until we get to the "real" start column
    Comparator<byte[]> comparator = reversed ? superColumn.getComparator().getReverseComparator()
            : superColumn.getComparator();
    while (subcolumns.hasNext()) {
        IColumn column = subcolumns.next();
        if (comparator.compare(column.name(), start) >= 0) {
            subcolumns = IteratorUtils.chainedIterator(IteratorUtils.singletonIterator(column), subcolumns);
            break;
        }
    }
    // subcolumns is either empty now, or has been redefined in the loop above.  either is ok.
    collectReducedColumns(scFiltered, subcolumns, gcBefore);
    return scFiltered;
}

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From source file:org.apache.cassandra.db.filter.SliceQueryFilter.java

public SuperColumn filterSuperColumn(SuperColumn superColumn, int gcBefore) {
    // we clone shallow, then add, under the theory that generally we're interested in a relatively small number of subcolumns.
    // this may be a poor assumption.
    SuperColumn scFiltered = superColumn.cloneMeShallow();
    Iterator<IColumn> subcolumns;
    if (reversed) {
        List<IColumn> columnsAsList = new ArrayList<IColumn>(superColumn.getSubColumns());
        subcolumns = new ReverseListIterator(columnsAsList);
    } else {/* www.  j  a v a2s  .  c om*/
        subcolumns = superColumn.getSubColumns().iterator();
    }

    // iterate until we get to the "real" start column
    Comparator<ByteBuffer> comparator = reversed ? superColumn.getComparator().reverseComparator
            : superColumn.getComparator();
    while (subcolumns.hasNext()) {
        IColumn column = subcolumns.next();
        if (comparator.compare(column.name(), start) >= 0) {
            subcolumns = IteratorUtils.chainedIterator(IteratorUtils.singletonIterator(column), subcolumns);
            break;
        }
    }
    // subcolumns is either empty now, or has been redefined in the loop above.  either is ok.
    collectReducedColumns(scFiltered, subcolumns, gcBefore);
    return scFiltered;
}

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From source file:org.apache.cayenne.access.jdbc.SQLTemplateAction.java

private void runWithNamedParametersBatch(Connection connection, OperationObserver callback, String template,
        Collection<Number> counts, boolean loggable) throws Exception {

    int size = query.parametersSize();

    // zero size indicates a one-shot query with no parameters
    // so fake a single entry batch...
    int batchSize = (size > 0) ? size : 1;

    // for now supporting deprecated batch parameters...
    @SuppressWarnings("unchecked")
    Iterator<Map<String, ?>> it = (size > 0) ? query.parametersIterator()
            : IteratorUtils.singletonIterator(Collections.emptyMap());
    for (int i = 0; i < batchSize; i++) {
        Map<String, ?> nextParameters = it.next();

        SQLStatement compiled = dataNode.getSqlTemplateProcessor().processTemplate(template, nextParameters);

        if (loggable) {
            dataNode.getJdbcEventLogger().logQuery(compiled.getSql(), compiled.getBindings(), 0);
        }//  w  w w .j a  v a  2s .com

        execute(connection, callback, compiled, counts);
    }

}

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From source file:org.apache.cayenne.map.ObjAttribute.java

@SuppressWarnings("unchecked")
public Iterator<CayenneMapEntry> getDbPathIterator(ObjEntity entity) {
    if (dbAttributePath == null) {
        return IteratorUtils.EMPTY_ITERATOR;
    }/*from   w  ww .  ja  v  a2  s  .  co  m*/

    if (entity == null) {
        return IteratorUtils.EMPTY_ITERATOR;
    }

    DbEntity dbEnt = entity.getDbEntity();
    if (dbEnt == null) {
        return IteratorUtils.EMPTY_ITERATOR;
    }

    int lastPartStart = dbAttributePath.lastIndexOf('.');
    if (lastPartStart < 0) {
        DbAttribute attribute = dbEnt.getAttribute(dbAttributePath);
        if (attribute == null) {
            return IteratorUtils.EMPTY_ITERATOR;
        }
        return IteratorUtils.singletonIterator(attribute);
    }

    return dbEnt.resolvePathComponents(dbAttributePath);
}

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From source file:org.objectstyle.cayenne.access.jdbc.SQLTemplateExecutionPlan.java

/**
 * Runs a SQLTemplate query as an update.
 *//* ww  w. j  a v  a2 s  .  com*/
public void execute(Connection connection, SQLTemplate query, OperationObserver observer)
        throws SQLException, Exception {

    SQLTemplateProcessor templateProcessor = new SQLTemplateProcessor();
    String template = query.getTemplate(adapter.getClass().getName());

    boolean loggable = QueryLogger.isLoggable(query.getLoggingLevel());
    int size = query.parametersSize();

    // zero size indicates a one-shot query with no parameters
    // so fake a single entry batch...
    int[] counts = new int[size > 0 ? size : 1];
    Iterator it = (size > 0) ? query.parametersIterator()
            : IteratorUtils.singletonIterator(Collections.EMPTY_MAP);
    for (int i = 0; i < counts.length; i++) {
        Map nextParameters = (Map) it.next();

        SQLStatement compiled = templateProcessor.processTemplate(template, nextParameters);

        if (loggable) {
            QueryLogger.logQuery(query.getLoggingLevel(), compiled.getSql(),
                    Arrays.asList(compiled.getBindings()));
        }

        // TODO: we may cache prep statements for this loop, using merged string as a key
        // since it is very likely that it will be the same for multiple parameter sets...
        PreparedStatement statement = connection.prepareStatement(compiled.getSql());
        try {
            bind(statement, compiled.getBindings());
            counts[i] = statement.executeUpdate();
            QueryLogger.logUpdateCount(query.getLoggingLevel(), counts[i]);
        } finally {
            statement.close();
        }
    }

    observer.nextBatchCount(query, counts);
}

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From source file:org.objectstyle.cayenne.access.jdbc.SQLTemplateSelectExecutionPlan.java

/**
 * Runs a SQLTemplate query as a select.
 *//*w  ww . j a  v a 2  s .co  m*/
public void execute(Connection connection, SQLTemplate query, OperationObserver observer)
        throws SQLException, Exception {

    SQLTemplateProcessor templateProcessor = new SQLTemplateProcessor();
    String template = query.getTemplate(adapter.getClass().getName());
    boolean loggable = QueryLogger.isLoggable(query.getLoggingLevel());

    int size = query.parametersSize();

    // zero size indicates a one-shot query with no parameters
    // so fake a single entry batch...
    Iterator it = (size > 0) ? query.parametersIterator()
            : IteratorUtils.singletonIterator(Collections.EMPTY_MAP);
    while (it.hasNext()) {
        Map nextParameters = (Map) it.next();

        SQLSelectStatement compiled = templateProcessor.processSelectTemplate(template, nextParameters);

        if (loggable) {
            QueryLogger.logQuery(query.getLoggingLevel(), compiled.getSql(),
                    Arrays.asList(compiled.getBindings()));
        }

        long t1 = System.currentTimeMillis();

        // TODO: we may cache prep statements for this loop, using merged string as a key
        // since it is very likely that it will be the same for multiple parameter sets...
        PreparedStatement statement = connection.prepareStatement(compiled.getSql());

        bind(statement, compiled.getBindings());
        ResultSet rs = statement.executeQuery();

        ResultDescriptor descriptor = (compiled.getResultColumns().length > 0)
                ? ResultDescriptor.createDescriptor(compiled.getResultColumns(), adapter.getExtendedTypes())
                : ResultDescriptor.createDescriptor(rs, adapter.getExtendedTypes());

        DefaultResultIterator result = new DefaultResultIterator(connection, statement, rs, descriptor,
                query.getFetchLimit());

        if (!observer.isIteratedResult()) {
            // note that we don't need to close ResultIterator
            // since "dataRows" will do it internally
            List resultRows = result.dataRows(true);
            QueryLogger.logSelectCount(query.getLoggingLevel(), resultRows.size(),
                    System.currentTimeMillis() - t1);

            observer.nextDataRows(query, resultRows);
        } else {
            try {
                result.setClosingConnection(true);
                observer.nextDataRows(query, result);
            } catch (Exception ex) {
                result.close();
                throw ex;
            }
        }
    }
}

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From source file:org.objectstyle.cayenne.map.ObjAttribute.java

public Iterator getDbPathIterator() {
    if (dbAttributePath == null) {
        return IteratorUtils.EMPTY_ITERATOR;
    }/* w w w. ja  v a 2  s  .  co  m*/

    ObjEntity ent = (ObjEntity) getEntity();
    if (ent == null) {
        return IteratorUtils.EMPTY_ITERATOR;
    }

    DbEntity dbEnt = ent.getDbEntity();
    if (dbEnt == null) {
        return IteratorUtils.EMPTY_ITERATOR;
    }

    int lastPartStart = dbAttributePath.lastIndexOf('.');
    if (lastPartStart < 0) {
        Attribute attribute = dbEnt.getAttribute(dbAttributePath);
        if (attribute == null) {
            return IteratorUtils.EMPTY_ITERATOR;
        }
        return IteratorUtils.singletonIterator(attribute);
    }

    return dbEnt.resolvePathComponents(dbAttributePath);
}

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