/*
* 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.cocoon.acting.modular;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Map;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.cocoon.util.JDBCTypeConversions;
/**
* Selects a record from a database. The action can select one or more
* tables, and can select from more than one row of a table at a
* time.
*
* @author <a href="mailto:haul@apache.org">Christian Haul</a>
* @version CVS $Id$
*/
public class DatabaseSelectAction extends DatabaseAction {
/**
* determine which mode to use as default mode
* here: SELECT
* highly specific to operation INSERT / UPDATE / DELETE / SELECT
*/
protected String selectMode ( boolean isAutoIncrement, Map modes ) {
return (String) modes.get( MODE_OTHERS );
}
/**
* determine whether autoincrement columns should be honoured by
* this operation. This is usually snsible only for INSERTs.
*/
protected boolean honourAutoIncrement() { return false; }
/**
* Get the String representation of the PreparedStatement. This is
* mapped to the Configuration object itself, so if it doesn't exist,
* it will be created.
*
* @param table the table's configuration object
* @return the insert query as a string
*/
protected CacheHelper getQuery( Configuration table, Map modeTypes, Map defaultModeNames )
throws ConfigurationException, ServiceException {
LookUpKey lookUpKey = new LookUpKey( table, modeTypes );
CacheHelper queryData = null;
synchronized( this.cachedQueryData ) {
queryData = (CacheHelper) this.cachedQueryData.get( lookUpKey );
if (queryData == null) {
Configuration[] keys = table.getChild("keys").getChildren("key");
Configuration[] values = table.getChild("values").getChildren("value");
queryData = new CacheHelper( keys.length, keys.length + values.length );
fillModes( keys , true , defaultModeNames, modeTypes, queryData );
fillModes( values, false, defaultModeNames, modeTypes, queryData );
StringBuffer queryBuffer = new StringBuffer("SELECT ");
//queryBuffer.append(table.getAttribute("name")).append(" WHERE ");
int count = 0;
for (int i = 0; i < queryData.columns.length; i++) {
if ( !queryData.columns[i].isKey ) {
if ( count > 0 ) {
queryBuffer.append(", ");
}
queryBuffer
.append( queryData.columns[i].columnConf.getAttribute( "name" ) );
count++;
}
}
queryBuffer.append(" FROM ").append(table.getAttribute("name")).append(" WHERE ");
count = 0;
for (int i = 0; i < queryData.columns.length; i++) {
if ( queryData.columns[i].isKey ) {
if ( count > 0 ) {
queryBuffer.append(" AND ");
}
queryBuffer
.append( queryData.columns[i].columnConf.getAttribute( "name" ) )
.append( "= ?");
count++;
}
}
queryData.queryString = queryBuffer.toString();
this.cachedQueryData.put( lookUpKey, queryData );
}
}
return queryData;
}
/**
* Fetch all values for all key columns that are needed to do the
* database operation.
*/
protected Object[][] getColumnValues( Configuration tableConf, CacheHelper queryData, Map objectModel )
throws ConfigurationException, ServiceException {
Object[][] columnValues = new Object[ queryData.columns.length ][];
for ( int i = 0; i < queryData.columns.length; i++ ){
if ( queryData.columns[i].isKey ) {
columnValues[i] = this.getColumnValue( tableConf, queryData.columns[i], objectModel );
} else {
// columnValues[i] = new Object[1]; // this should not be needed
}
}
return columnValues;
}
/**
* set all necessary ?s and execute the query
*/
protected int processRow ( Map objectModel, Connection conn, PreparedStatement statement, String outputMode,
Configuration table, CacheHelper queryData, Object[][] columnValues,
int rowIndex, Map results )
throws SQLException, ConfigurationException, Exception {
int currentIndex = 1;
// ordering is different for SELECT just needs keys
for (int i = 0; i < queryData.columns.length; i++) {
Column col = queryData.columns[i];
if ( col.isKey ) {
this.setColumn(objectModel, outputMode, results, table, col.columnConf, rowIndex,
columnValues[ i ][ ( col.isSet ? rowIndex : 0 ) ], statement, currentIndex );
currentIndex++;
}
}
statement.execute();
// retrieve values
ResultSet resultset = statement.getResultSet();
rowIndex = 0;
while ( resultset.next() ){
for (int i = 0; i < queryData.columns.length; i++) {
if ( !queryData.columns[i].isKey ) {
Object value = JDBCTypeConversions.getColumn( resultset, queryData.columns[i].columnConf );
this.setOutput(objectModel, outputMode, results, table, queryData.columns[i].columnConf, rowIndex, value);
}
}
rowIndex++;
}
if (rowIndex == 0) { results = EMPTY_MAP;}
return rowIndex;
}
}