/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.commons.dbutils.handlers;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* <code>ResultSetHandler</code> implementation that converts one
* <code>ResultSet</code> column into a <code>List</code> of
* <code>Object</code>s. This class is thread safe.
*
* @see org.apache.commons.dbutils.ResultSetHandler
* @since DbUtils 1.1
*/
public class ColumnListHandler extends AbstractListHandler<Object> {
/**
* The column number to retrieve.
*/
private final int columnIndex;
/**
* The column name to retrieve. Either columnName or columnIndex
* will be used but never both.
*/
private final String columnName;
/**
* Creates a new instance of ColumnListHandler. The first column of each
* row will be returned from <code>handle()</code>.
*/
public ColumnListHandler() {
this(1, null);
}
/**
* Creates a new instance of ColumnListHandler.
*
* @param columnIndex The index of the column to retrieve from the
* <code>ResultSet</code>.
*/
public ColumnListHandler(int columnIndex) {
this(columnIndex, null);
}
/**
* Creates a new instance of ColumnListHandler.
*
* @param columnName The name of the column to retrieve from the
* <code>ResultSet</code>.
*/
public ColumnListHandler(String columnName) {
this(1, columnName);
}
/** Private Helper
* @param columnIndex The index of the column to retrieve from the
* <code>ResultSet</code>.
* @param columnName The name of the column to retrieve from the
* <code>ResultSet</code>.
*/
private ColumnListHandler(int columnIndex, String columnName) {
super();
this.columnIndex = columnIndex;
this.columnName = columnName;
}
/**
* Returns one <code>ResultSet</code> column value as <code>Object</code>.
* @param rs <code>ResultSet</code> to process.
* @return <code>Object</code>, never <code>null</code>.
*
* @throws SQLException if a database access error occurs
*
* @see org.apache.commons.dbutils.handlers.AbstractListHandler#handle(ResultSet)
*/
protected Object handleRow(ResultSet rs) throws SQLException {
if (this.columnName == null) {
return rs.getObject(this.columnIndex);
} else {
return rs.getObject(this.columnName);
}
}
}
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