/*
* 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 org.apache.beehive.controls.system.jdbc.JdbcControl.SQL;
import java.lang.reflect.Method;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Calendar;
/**
* Default ResultSetMapper implementation for Objects.
*/
public class DefaultObjectResultSetMapper extends ResultSetMapper {
/**
* static reference to the TypeMappingsFactory for this class
*/
protected static final TypeMappingsFactory _tmf = TypeMappingsFactory.getInstance();
/**
* Map the ResultSet to the method's return type. The object type returned is defined by the return type of the method.
*
* @param context A ControlBeanContext instance, see Beehive controls javadoc for additional information
* @param m Method assoicated with this call.
* @param resultSet Result set to map.
* @param cal A Calendar instance for time/date value resolution.
* @return The Object resulting from the ResultSet
*/
public Object mapToResultType(ControlBeanContext context, Method m, ResultSet resultSet, Calendar cal) {
final Class returnType = m.getReturnType();
final boolean isArray = returnType.isArray();
try {
if (isArray) {
final SQL methodSQL = (SQL) context.getMethodPropertySet(m, SQL.class);
return arrayFromResultSet(resultSet, methodSQL.arrayMaxLength(), returnType, cal);
} else {
if (!resultSet.next()) {
return _tmf.fixNull(m.getReturnType());
}
return RowMapperFactory.getRowMapper(resultSet, returnType, cal).mapRowToReturnType();
}
} catch (SQLException e) {
throw new ControlException(e.getMessage(), e);
}
}
//
// ////////////////////////////////// PRIVATE METHODS //////////////////////////////////////////
//
/**
* Invoked when the return type of the method is an array type.
*
* @param rs ResultSet to process.
* @param maxRows The maximum size of array to create
* @param arrayClass The class of object contained within the array
* @param cal A calendar instance to use for date/time values
* @return An array of the specified class type
* @throws SQLException On error.
*/
protected Object arrayFromResultSet(ResultSet rs, int maxRows, Class arrayClass, Calendar cal)
throws SQLException {
Class componentType = arrayClass.getComponentType();
ResultSetMetaData md = rs.getMetaData();
ArrayList<Object> list = new ArrayList<Object>();
int numRows;
boolean hasMoreRows = rs.next();
RowMapper rowMapper = RowMapperFactory.getRowMapper(rs, componentType, cal);
for (numRows = 0; numRows != maxRows && hasMoreRows; numRows++) {
list.add(rowMapper.mapRowToReturnType());
hasMoreRows = rs.next();
}
Object array = java.lang.reflect.Array.newInstance(componentType, numRows);
try {
for (int i = 0; i < numRows; i++) {
java.lang.reflect.Array.set(array, i, list.get(i));
}
} catch (IllegalArgumentException iae) {
// assuming no errors in resultSetObject() this can only happen
// for single column result sets.
throw new ControlException("The declared Java type for array " + componentType.getName()
+ "is incompatible with the SQL format of column " + md.getColumnName(1)
+ md.getColumnTypeName(1) + "which returns objects of type + "
+ list.get(0).getClass().getName());
}
return array;
}
}