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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2002, 2015 Oracle and/or its affiliates. All rights reserved.
*
*/
package com.sleepycat.persist;
import java.util.Iterator;
import java.util.NoSuchElementException;
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.LockMode;
import com.sleepycat.util.RuntimeExceptionWrapper;
/**
* Implements Iterator for an arbitrary EntityCursor.
*
* @author Mark Hayes
*/
class BasicIterator<V> implements Iterator<V> {
private EntityCursor<V> entityCursor;
private ForwardCursor<V> forwardCursor;
private LockMode lockMode;
private V nextValue;
/**
* An EntityCursor is given and the remove() method is supported.
*/
BasicIterator(EntityCursor<V> entityCursor, LockMode lockMode) {
this.entityCursor = entityCursor;
this.forwardCursor = entityCursor;
this.lockMode = lockMode;
}
/**
* A ForwardCursor is given and the remove() method is not supported.
*/
BasicIterator(ForwardCursor<V> forwardCursor, LockMode lockMode) {
this.forwardCursor = forwardCursor;
this.lockMode = lockMode;
}
public boolean hasNext() {
if (nextValue == null) {
try {
nextValue = forwardCursor.next(lockMode);
} catch (DatabaseException e) {
throw RuntimeExceptionWrapper.wrapIfNeeded(e);
}
return nextValue != null;
} else {
return true;
}
}
public V next() {
if (hasNext()) {
V v = nextValue;
nextValue = null;
return v;
} else {
throw new NoSuchElementException();
}
}
public void remove() {
if (entityCursor == null) {
throw new UnsupportedOperationException();
}
try {
if (!entityCursor.delete()) {
throw new IllegalStateException
("Record at cursor position is already deleted");
}
} catch (DatabaseException e) {
throw RuntimeExceptionWrapper.wrapIfNeeded(e);
}
}
}
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