/*
* Copyright 2005 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* $Header:$
*/
package org.apache.beehive.controls.system.jdbc;
import org.apache.beehive.controls.api.ControlException;
import org.apache.beehive.controls.api.context.ControlBeanContext;
import java.lang.reflect.Method;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Calendar;
import java.util.NoSuchElementException;
/**
* Used by DefaultIteratorResultSetMapper for mapping a ResultSet to an Iterator type.
*/
public class ResultSetIterator implements java.util.Iterator {
private final Class _returnClass;
private final ResultSet _rs;
private final RowMapper _rowMapper;
private boolean _primed = false;
/**
* Create a new ResultSetIterator.
* @param context A ControlBeanContext.
* @param method The annotated method.
* @param rs The ResultSet to map.
* @param cal A Calendar instance for mapping date/time values.
*/
ResultSetIterator(ControlBeanContext context, Method method, ResultSet rs, Calendar cal) {
_rs = rs;
JdbcControl.SQL methodSQL = (JdbcControl.SQL) context.getMethodPropertySet(method, JdbcControl.SQL.class);
_returnClass = methodSQL.iteratorElementType();
if (_returnClass == null) {
throw new ControlException("Invalid return class declared for Iterator:" + _returnClass.getName());
}
_rowMapper = RowMapperFactory.getRowMapper(rs, _returnClass, cal);
}
/**
* Does this iterater have more elements?
* @return true if there is another element
*/
public boolean hasNext() {
if (_primed) {
return true;
}
try {
_primed = _rs.next();
} catch (SQLException sqle) {
return false;
}
return _primed;
}
/**
* Get the next element in the iteration.
* @return The next element in the iteration.
*/
public Object next() {
try {
if (!_primed) {
_primed = _rs.next();
if (!_primed) {
throw new NoSuchElementException();
}
}
// reset upon consumption
_primed = false;
return _rowMapper.mapRowToReturnType();
} catch (SQLException e) {
// Since Iterator interface is locked, all we can do
// is put the real exception inside an expected one.
NoSuchElementException xNoSuch = new NoSuchElementException("ResultSet exception: " + e);
xNoSuch.initCause(e);
throw xNoSuch;
}
}
/**
* Remove is currently not supported.
*/
public void remove() {
throw new UnsupportedOperationException("remove not supported");
}
}