95 lines
2.3 KiB
Java
95 lines
2.3 KiB
Java
package eu.dnetlib.enabling.resultset.client;
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import java.util.Iterator;
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import java.util.LinkedList;
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import java.util.List;
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import java.util.NoSuchElementException;
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import java.util.Queue;
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import org.apache.commons.logging.Log;
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import org.apache.commons.logging.LogFactory;
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import eu.dnetlib.enabling.resultset.client.utils.ResultSetRuntimeException;
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import eu.dnetlib.enabling.resultset.client.utils.ResultSetTimeoutException;
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import eu.dnetlib.enabling.resultset.rmi.ResultSetException;
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import eu.dnetlib.enabling.resultset.rmi.ResultSetService;
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/**
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*
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* @author claudio
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*
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*/
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public class ResultSetClientIterator implements Iterator<String> {
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/**
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* logger
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*/
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private static final Log log = LogFactory.getLog(ResultSetClientIterator.class);
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/**
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* the page source
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*/
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private ResultSetPageProvider pageProvider;
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/**
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* buffer used to provide a single element for the next() method
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*/
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private Queue<String> buffer;
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public ResultSetClientIterator(ResultSetService resultSet, String rsId)
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throws ResultSetRuntimeException {
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pageProvider = new ResultSetPageProvider(resultSet, rsId);
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buffer = new LinkedList<String>();
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}
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public ResultSetClientIterator(ResultSetService resultSet, String rsId, int pageSize) {
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this(resultSet, rsId);
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pageProvider.setPageSize(pageSize);
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}
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public ResultSetClientIterator(ResultSetService resultSet, String rsId, int pageSize, long timeout) {
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this(resultSet, rsId, pageSize);
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pageProvider.setMaxWaitTime(timeout);
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}
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/**
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* Tries to refill the buffer with a nextPage()
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* @return true if the buffer was filled successfully, false otherwise
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* @throws ResultSetTimeoutException in case of timeout
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* @throws ResultSetException
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* @throws ResultSetException
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*/
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private boolean refillBuffer() throws ResultSetTimeoutException, ResultSetRuntimeException {
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List<String> page = pageProvider.nextPage();
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if (page != null && !page.isEmpty()) {
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buffer.addAll(page);
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return true;
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}
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return false;
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}
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@Override
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public boolean hasNext() {
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if (!buffer.isEmpty())
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return true;
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return refillBuffer();
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}
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@Override
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public String next() {
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if (!hasNext()) {
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log.info("NoSuchElementException");
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throw new NoSuchElementException();
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}
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return buffer.poll();
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}
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@Override
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public void remove() {
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throw new UnsupportedOperationException();
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}
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}
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