/**
* 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.oodt.xmlps.product;
//OODT imports
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Stack;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;
//OODT imports
import org.apache.oodt.xmlps.mapping.DatabaseTable;
import org.apache.oodt.xmlps.mapping.Mapping;
import org.apache.oodt.xmlps.mapping.FieldScope;
import org.apache.oodt.xmlps.mapping.MappingField;
import org.apache.oodt.xmlps.mapping.MappingReader;
import org.apache.oodt.xmlps.mapping.funcs.MappingFunc;
import org.apache.oodt.xmlps.queryparser.Expression;
import org.apache.oodt.xmlps.queryparser.HandlerQueryParser;
import org.apache.oodt.xmlps.structs.CDEResult;
import org.apache.oodt.xmlps.structs.CDERow;
import org.apache.oodt.xmlps.structs.CDEValue;
import org.apache.oodt.xmlps.util.XMLQueryHelper;
//OODT imports
import org.apache.oodt.product.ProductException;
import org.apache.oodt.product.QueryHandler;
import org.apache.oodt.xmlquery.QueryElement;
import org.apache.oodt.xmlquery.Result;
import org.apache.oodt.xmlquery.XMLQuery;
/**
*
* <p>
* An XML configurable version of a Product Server that requires no code
* to be written to plug into a local site's relational backend DBMS.
* </p>.
*/
public class XMLPSProductHandler implements QueryHandler {
/* our log stream */
private static final Logger LOG = Logger
.getLogger(XMLPSProductHandler.class.getName());
protected Mapping mapping;
private DBMSExecutor executor;
protected XMLPSProductHandler(String phony) {
/* this is to get around invoking the default constructor in sub-classes */
}
public XMLPSProductHandler() throws InstantiationException {
String MappingFilePath = System
.getProperty("org.apache.oodt.xmlps.xml.mapFilePath");
if (MappingFilePath == null) {
throw new InstantiationException(
"Need to specify path to xml mapping file!");
}
try {
mapping = MappingReader.getMapping(MappingFilePath);
} catch (Exception e) {
throw new InstantiationException(
"Unable to parse mapping xml file: ["
+ MappingFilePath + "]: reason: "
+ e.getMessage());
}
/* load the db properties file */
/*
* if one exists: otherwise, don't bother and just print out the SQL to
* the console.
*/
String dbPropFilePath = System
.getProperty("org.apache.oodt.xmlps.xml.dbPropFilePath");
if (dbPropFilePath != null) {
try {
System.getProperties()
.load(new FileInputStream(dbPropFilePath));
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
throw new InstantiationException(e.getMessage());
}
executor = new DBMSExecutor();
}
}
/*
* (non-Javadoc)
*
* @see org.apache.oodt.product.QueryHandler#query(org.apache.oodt.xmlquery.XMLQuery)
*/
public XMLQuery query(XMLQuery query) throws ProductException {
List<QueryElement> whereSet = query.getWhereElementSet();
List<QueryElement> selectSet = query.getSelectElementSet();
try {
translateToDomain(selectSet, true);
translateToDomain(whereSet, false);
} catch (Exception e) {
e.printStackTrace();
throw new ProductException(e.getMessage());
}
queryAndPackageResults(query);
return query;
}
public static void main(String[] args) throws Exception {
String usage = "XMLPSProductHandler <query>\n";
if (args.length != 1) {
System.err.println(usage);
System.exit(1);
}
XMLPSProductHandler handler = new XMLPSProductHandler();
XMLQuery q = handler.query(XMLQueryHelper
.getDefaultQueryFromQueryString(args[0]));
System.out.println(q.getXMLDocString());
}
protected List<QueryElement> getElemNamesFromQueryElemSet(
List<QueryElement> origSet) {
if (origSet == null || (origSet != null && origSet.size() == 0))
return null;
List<QueryElement> newSet = new Vector<QueryElement>();
for (Iterator<QueryElement> i = origSet.iterator(); i.hasNext();) {
QueryElement elem = i.next();
if (elem.getRole().equals(XMLQueryHelper.ROLE_ELEMNAME)
&& !mapping.constantField(elem.getValue())) {
newSet.add(elem);
}
}
return newSet;
}
protected List<QueryElement> getConstElemNamesFromQueryElemSet(
List<QueryElement> origSet) {
if (origSet == null || (origSet != null && origSet.size() == 0))
return null;
List<QueryElement> newSet = new Vector<QueryElement>();
for (Iterator<QueryElement> i = origSet.iterator(); i.hasNext();) {
QueryElement elem = i.next();
if (elem.getRole().equals(XMLQueryHelper.ROLE_ELEMNAME)
&& mapping.constantField(elem.getValue())) {
newSet.add(elem);
}
}
return newSet;
}
protected void queryAndPackageResults(XMLQuery query) {
Stack<QueryElement> queryStack = HandlerQueryParser
.createQueryStack(query.getWhereElementSet());
Expression parsedQuery = HandlerQueryParser.parse(queryStack,
this.mapping);
List<QueryElement> names = getElemNamesFromQueryElemSet(query
.getSelectElementSet());
String querySelectNames = toNames(names);
StringBuffer sqlBuf = new StringBuffer("SELECT ");
sqlBuf.append(querySelectNames);
sqlBuf.append(" FROM ");
sqlBuf.append(mapping.getDefaultTable());
sqlBuf.append(" ");
if (mapping.getNumTables() > 0) {
for (Iterator<String> i = mapping.getTableNames().iterator(); i
.hasNext();) {
String tableName = i.next();
DatabaseTable tbl = mapping.getTableByName(tableName);
sqlBuf.append("INNER JOIN ");
sqlBuf.append(tbl.getName());
sqlBuf.append(" ON ");
sqlBuf.append(tbl.getName());
sqlBuf.append(".");
sqlBuf.append(tbl.getJoinFieldName());
sqlBuf.append(" = ");
sqlBuf.append((tbl.getDefaultTableJoin() != null &&
!tbl.getDefaultTableJoin().equals("")) ? tbl
.getDefaultTableJoin() : mapping.getDefaultTable());
sqlBuf.append(".");
sqlBuf.append(tbl.getDefaultTableJoinFieldName());
sqlBuf.append(" ");
}
}
if(parsedQuery != null){
sqlBuf.append(" WHERE ");
sqlBuf.append(parsedQuery.evaluate());
}
LOG.log(Level.INFO, sqlBuf.toString());
if (executor != null) {
try {
CDEResult res = executor.executeLocalQuery(this.mapping,
sqlBuf.toString(), Arrays.asList(querySelectNames
.split(",")));
res = addConstFields(res,
getConstElemNamesFromQueryElemSet(query
.getSelectElementSet()));
if (res.getRows() == null
|| (res.getRows() != null && res.getRows().size() == 0)) {
}
Result r = res.toResult();
if (r != null) {
query.getResults().add(r);
}
} catch (SQLException e) {
e.printStackTrace();
LOG.log(Level.WARNING, "Error executing sql: ["
+ sqlBuf.toString() + "]: Message: " + e.getMessage());
}
}
}
private CDEResult addConstFields(CDEResult res,
List<QueryElement> constFlds) {
CDEResult newRes = res;
if (constFlds != null && constFlds.size() > 0) {
if (res == null
|| (res != null && (res.getRows() == null || (res.getRows() != null && res
.getRows().size() == 0)))) {
newRes = new CDEResult();
// add one row
newRes.getRows().add(new CDERow());
}
for (Iterator<QueryElement> i = constFlds.iterator(); i.hasNext();) {
QueryElement elem = i.next();
MappingField fld = this.mapping.getFieldByLocalName(elem
.getValue());
for (Iterator<CDERow> j = newRes.getRows().iterator(); j
.hasNext();) {
CDERow row = j.next();
CDEValue val = new CDEValue(fld.getName(), fld
.getConstantValue());
row.getVals().add(val);
}
}
}
return newRes;
}
private String toNames(List<QueryElement> elems) {
if (elems == null || (elems != null && elems.size() == 0))
return null;
StringBuffer buf = new StringBuffer();
for (Iterator<QueryElement> i = elems.iterator(); i.hasNext();) {
QueryElement elem = i.next();
buf.append(elem.getValue());
buf.append(",");
}
buf.deleteCharAt(buf.length() - 1);
return buf.toString();
}
protected void translateToDomain(List<QueryElement> elemSet,
boolean selectSet) throws Exception {
// go through each query element: use the mapping fields
// to translate the names
for (Iterator<QueryElement> i = elemSet.iterator(); i.hasNext();) {
QueryElement elem = i.next();
if (elem.getRole().equals(XMLQueryHelper.ROLE_ELEMNAME)) {
// do the translation
String elemValue = elem.getValue();
MappingField fld = this.mapping.getFieldByName(elemValue);
// make sure fld is not null
if (fld == null) {
continue;
}
// make sure scope is null, or if it's not null, then it's
// FieldScope.QUERY
if (fld.getScope() != null
&& fld.getScope().equals(FieldScope.RETURN)) {
// skip
continue;
}
// check to see if it has a dbname attr, if not, then the name
// stays
// the same
String newFldName = this.mapping.getFieldLocalName(fld);
elem.setValue(newFldName);
// now translate the domain vocab if there are translate funcs
// present and this isn't the select set
if (!selectSet && fld.getFuncs() != null
&& fld.getFuncs().size() > 0) {
// the next query element should be
// XMLQueryHelper.ROLE_LITERAL
if (!i.hasNext())
break;
QueryElement litElem = i.next();
if (!litElem.getRole().equals(XMLQueryHelper.ROLE_LITERAL)) {
throw new Exception("next query element not "
+ XMLQueryHelper.ROLE_LITERAL + "! role is "
+ litElem.getRole() + " instead!");
}
for (Iterator<MappingFunc> j = fld.getFuncs().iterator(); j
.hasNext();) {
MappingFunc func = j.next();
CDEValue origVal = new CDEValue(fld.getName(),
litElem.getValue());
CDEValue newVal = func.translate(origVal);
litElem.setValue(newVal.getVal());
}
}
}
}
}
}