org.plasma.sdo.jdbc.service.GraphQuery Maven / Gradle / Ivy
/**
* PlasmaSDO™ License
*
* This is a community release of PlasmaSDO™, a dual-license
* Service Data Object (SDO) 2.1 implementation.
* This particular copy of the software is released under the
* version 2 of the GNU General Public License. PlasmaSDO™ was developed by
* TerraMeta Software, Inc.
*
* Copyright (c) 2013, TerraMeta Software, Inc. All rights reserved.
*
* General License information can be found below.
*
* This distribution may include materials developed by third
* parties. For license and attribution notices for these
* materials, please refer to the documentation that accompanies
* this distribution (see the "Licenses for Third-Party Components"
* appendix) or view the online documentation at
* > queryResults = findResults(query, collector, type, con);
GraphAssembler assembler =
new GraphAssembler(type,
collector,
snapshotDate, con);
if (log.isDebugEnabled() ){
log.debug("assembling results");
}
PlasmaDataGraph[] results = null;
try {
if (!query.getSelectClause().hasDistinctProperties())
results = assembleResults(queryResults,
requestMax, assembler);
else
results = trimResults(queryResults,
requestMax, assembler, query.getSelectClause(), type);
}
finally {
try {
con.close();
} catch (SQLException e) {
log.error(e.getMessage(), e);
}
}
return results;
}
/**
* Returns a count of the given query. This does NOT return any results but causes
* a "count(*)" to be issued.
* @param query the Query Object Model (QOM) query
* @return the query results size
*/
public int count(Query query)
{
Connection con = null;
try {
con = RDBConnectionManager.instance().getConnection();
} catch (SQLException e2) {
throw new DataAccessException(e2);
}
From from = query.getFromClause();
PlasmaType type = (PlasmaType)PlasmaTypeHelper.INSTANCE.getType(from.getEntity().getNamespaceURI(),
from.getEntity().getName());
int size = this.countResults(con, query, type);
try {
con.close();
} catch (SQLException e) {
log.error(e.getMessage(), e);
}
return size;
}
/**
* Iterate over the given results collection up to the given limit, assembling a data-object
* graph for each result. In the simplest case, only a single root data-object
* is assembled.
* @param collection - the results collection
* @param requestMax - the requested max or limit of items required in the results. If results exceed
* the given maximum, then they are truncated. If no maximum
* value is given (e.g. -1) then a default max is enforced.
* @param assembler - the value object assembler
* @throws MaxResultsExceededException when no request maximum is given and the default
* max is exceeded.
*/
private PlasmaDataGraph[] assembleResults(List> collection,
int requestMax, GraphAssembler assembler)
{
ArrayList list = new ArrayList(20);
Iterator> iter = collection.iterator();
for (int i = 1; iter.hasNext(); i++)
{
List pairs = iter.next();
if (requestMax <= 0)
{
if (i > QueryConstants.MAX_RESULTS) // note: this is cheezy but checking the collection size is expensive
throw new MaxResultsExceededException(i, QueryConstants.MAX_RESULTS);
}
else if (i > requestMax)
{
if (log.isDebugEnabled() ){
log.debug("truncating results at " + String.valueOf(requestMax));
}
break;
}
assembler.assemble(pairs);
list.add(assembler.getDataGraph());
assembler.clear();
}
PlasmaDataGraph[] results = new PlasmaDataGraph[list.size()];
list.toArray(results);
if (log.isDebugEnabled() ){
log.debug("assembled " + String.valueOf(results.length) + " results");
}
return results;
}
/**
* Iterates over the given results collection pruning value-object results after assembly based
* on any "distinct" property(ies) in the results object graph. Results must be pruned/trimmed
* after assembly because the assembly invokes POM traversals/queries where the "distinct" propertiy(ies)
* are realized. For each result, a hash key is assembled to determine it's uniqueness based on a search
* of the assembled value-object graph for "distinct" properties as defined in the given Query select
* clause.
* @param collection - the results collection
* @param requestMax - the requested max or limit of items required in the results. If results exceed
* the given maximum, then they are truncated. If no maximum
* value is given (e.g. -1) then a default max is enforced.
* @param assembler - the value object assembler
* @param select the Query select clause
* @param type the candidate Type definition
* @throws MaxResultsExceededException when no request maximum is given and the default max is exceeded.
*/
private PlasmaDataGraph[] trimResults(List> collection,
int requestMax, GraphAssembler assembler, Select select, Type type)
{
DataObjectHashKeyAssembler hashKeyAssembler =
new DataObjectHashKeyAssembler(select, type);
// FIXME rely on non-ordered map to retain initial ordering and get
// rid of list collection.
Map distinctMap = new HashMap(20);
List distinctList = new ArrayList(20);
Iterator> iter = collection.iterator();
int i;
for (i = 1; iter.hasNext(); i++)
{
if (requestMax <= 0 && i > QueryConstants.MAX_RESULTS) // note: this is cheezy but checking the collection size is expensive
throw new MaxResultsExceededException(i, QueryConstants.MAX_RESULTS);
List pairs = iter.next();
assembler.assemble(pairs);
PlasmaDataGraph dataGraph = assembler.getDataGraph();
assembler.clear();
String key = hashKeyAssembler.getHashKey((PlasmaDataObject)dataGraph.getRootObject());
if (distinctMap.get(key) == null)
{
if (requestMax <= 0)
{
if (i > QueryConstants.MAX_RESULTS) // note: this is cheezy but checking the collection size is expensive
throw new MaxResultsExceededException(distinctList.size(), QueryConstants.MAX_RESULTS);
}
else if (i > requestMax)
{
if (log.isDebugEnabled() ){
log.debug("truncating results at " + String.valueOf(requestMax));
}
break;
}
distinctMap.put(key, (PlasmaDataObject)dataGraph.getRootObject());
distinctList.add((PlasmaDataObject)dataGraph.getRootObject());
}
}
PlasmaDataGraph[] trimmedResults = new PlasmaDataGraph[distinctList.size()];
for (i = 0; i < trimmedResults.length; i++)
trimmedResults[i] = (PlasmaDataGraph) distinctList.get(i).getDataGraph();
if (log.isDebugEnabled() ){
log.debug("assembled " + String.valueOf(trimmedResults.length) + " results out of " + String.valueOf(i));
}
return trimmedResults;
}
private int countResults(Connection con, Query query, PlasmaType type)
{
int result = 0;
Object[] params = new Object[0];
FilterAssembler filterAssembler = null;
StringBuilder sqlQuery = new StringBuilder();
AliasMap aliasMap = new AliasMap(type);
sqlQuery.append("SELECT COUNT(*)");
sqlQuery.append(aliasMap.getAlias(type));
Statement statement = null;
ResultSet rs = null;
try {
Where where = query.findWhereClause();
if (where != null)
{
filterAssembler = new FilterAssembler(where, type, aliasMap);
sqlQuery.append(" ");
sqlQuery.append(filterAssembler.getFilter());
params = filterAssembler.getParams();
if (log.isDebugEnabled() ){
log.debug("filter: " + filterAssembler.getFilter());
}
}
else {
sqlQuery.append(" FROM ");
sqlQuery.append(getQualifiedPhysicalName(type));
sqlQuery.append(" ");
sqlQuery.append(aliasMap.getAlias(type));
}
if(query.getStartRange() != null && query.getEndRange() != null)
log.warn("query range (start: "
+ query.getStartRange() + ", end: "
+ query.getEndRange() + ") ignored for count operation");
if (log.isDebugEnabled() ){
log.debug("queryString: " + sqlQuery.toString());
log.debug("executing...");
}
statement = con.createStatement(
ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
statement.execute(sqlQuery.toString());
rs = statement.getResultSet();
rs.first();
result = rs.getInt(1);
}
catch (Throwable t) {
StringBuffer buf = this.generateErrorDetail(t, sqlQuery.toString(),
filterAssembler);
log.error(buf.toString());
throw new DataAccessException(t);
}
finally {
try {
if (rs != null)
rs.close();
if (statement != null)
statement.close();
} catch (SQLException e) {
log.error(e.getMessage(), e);
}
}
return result;
}
private List> findResults(Query query, PropertySelectionCollector collector,
PlasmaType type, Connection con)
{
Object[] params = new Object[0];
RDBDataConverter converter = RDBDataConverter.INSTANCE;
if (log.isDebugEnabled() ){
log(query);
}
AliasMap aliasMap = new AliasMap(type);
Map> selectMap = collector.getResult();
// construct a filter adding to alias map
FilterAssembler filterAssembler = null;
Where where = query.findWhereClause();
if (where != null)
{
filterAssembler = new FilterAssembler(where, type, aliasMap);
params = filterAssembler.getParams();
}
OrderingDeclarationAssembler orderingDeclAssembler = null;
OrderBy orderby = query.findOrderByClause();
if (orderby != null)
orderingDeclAssembler = new OrderingDeclarationAssembler(orderby, type,
aliasMap);
GroupingDeclarationAssembler groupingDeclAssembler = null;
GroupBy groupby = query.findGroupByClause();
if (groupby != null)
groupingDeclAssembler = new GroupingDeclarationAssembler(groupby, type,
aliasMap);
String rootAlias = aliasMap.getAlias(type);
StringBuilder sqlQuery = new StringBuilder();
sqlQuery.append("SELECT ");
int i = 0;
List names = selectMap.get(type);
for (String name : names) {
PlasmaProperty prop = (PlasmaProperty)type.getProperty(name);
if (prop.isMany() && !prop.getType().isDataType())
continue;
if (i > 0)
sqlQuery.append(", ");
sqlQuery.append(rootAlias);
sqlQuery.append(".");
sqlQuery.append(prop.getPhysicalName());
i++;
}
// construct a FROM clause from alias map
sqlQuery.append(" FROM ");
Iterator it = aliasMap.getTypes();
int count = 0;
while (it.hasNext()) {
PlasmaType aliasType = it.next();
String alias = aliasMap.getAlias(aliasType);
if (count > 0)
sqlQuery.append(", ");
sqlQuery.append(getQualifiedPhysicalName(aliasType));
sqlQuery.append(" ");
sqlQuery.append(alias);
count++;
}
// append WHERE filter
if (filterAssembler != null) {
sqlQuery.append(" ");
sqlQuery.append(filterAssembler.getFilter());
}
// set the result range
// FIXME: Oracle specific
if(query.getStartRange() != null && query.getEndRange() != null) {
if (where == null)
sqlQuery.append(" WHERE ");
else
sqlQuery.append(" AND ");
sqlQuery.append("ROWNUM >= ");
sqlQuery.append(String.valueOf(query.getStartRange()));
sqlQuery.append(" AND ROWNUM <= ");
sqlQuery.append(String.valueOf(query.getEndRange()));
}
if (orderingDeclAssembler != null) {
sqlQuery.append(" ");
sqlQuery.append(orderingDeclAssembler.getOrderingDeclaration());
}
if (groupingDeclAssembler != null) {
sqlQuery.append(" ");
sqlQuery.append(groupingDeclAssembler.getGroupingDeclaration());
}
List> rows = new ArrayList>();
PreparedStatement statement = null;
ResultSet rs = null;
try {
statement = con.prepareStatement(sqlQuery.toString(),
ResultSet.TYPE_FORWARD_ONLY,/*ResultSet.TYPE_SCROLL_INSENSITIVE,*/
ResultSet.CONCUR_READ_ONLY);
// set params
// note params are pre-converted
// to string in filter assembly
// FIXME: are parameters relevant in SQL in this context?
if (filterAssembler != null) {
params = filterAssembler.getParams();
if (params != null)
for (i = 0; i < params.length; i++)
statement.setString(i+1,
String.valueOf(params[i]));
}
if (log.isDebugEnabled() ){
if (params == null || params.length == 0) {
log.debug("executing: "+ sqlQuery.toString());
}
else
{
StringBuilder paramBuf = new StringBuilder();
paramBuf.append(" [");
for (int p = 0; p < params.length; p++)
{
if (p > 0)
paramBuf.append(", ");
paramBuf.append(String.valueOf(params[p]));
}
paramBuf.append("]");
log.debug("executing: "+ sqlQuery.toString()
+ " " + paramBuf.toString());
}
}
statement.execute();
rs = statement.getResultSet();
int numcols = rs.getMetaData().getColumnCount();
ResultSetMetaData rsMeta = rs.getMetaData();
List row = null;
PropertyPair pair = null;
while(rs.next()) {
row = new ArrayList();
rows.add(row);
for(i=1;i<=numcols;i++) {
String columnName = rsMeta.getColumnName(i);
int columnType = rsMeta.getColumnType(i);
PlasmaProperty prop = (PlasmaProperty)type.getProperty(columnName);
Object value = converter.fromJDBCDataType(rs,
i, columnType, prop);
pair = new PropertyPair(prop, value);
pair.setColumn(i);
row.add(pair);
}
}
}
catch (Throwable t) {
StringBuffer buf = this.generateErrorDetail(t,
sqlQuery.toString(),
filterAssembler);
log.error(buf.toString());
throw new DataAccessException(t);
}
finally {
try {
if (rs != null)
rs.close();
if (statement != null)
statement.close();
} catch (SQLException e) {
log.error(e.getMessage(), e);
}
}
return rows;
}
private StringBuffer generateErrorDetail(Throwable t, String queryString,
FilterAssembler filterAssembler)
{
StringBuffer buf = new StringBuffer(2048);
buf.append("QUERY FAILED: ");
buf.append(t.getMessage());
buf.append(" \n");
if (queryString != null) {
buf.append("queryString: ");
buf.append(queryString);
buf.append(" \n");
}
if (filterAssembler != null) {
if (filterAssembler.hasImportDeclarations())
{
buf.append("import decl: ");
buf.append(filterAssembler.getImportDeclarations());
buf.append(" \n");
}
Object[] params = filterAssembler.getParams();
if (params != null)
{
buf.append("parameters: [");
for (int i = 0; i < params.length; i++)
{
if (i > 0)
buf.append(", ");
buf.append(String.valueOf(params[i]));
}
buf.append("]");
buf.append(" \n");
}
if (filterAssembler.hasParameterDeclarations())
{
buf.append("param decl: ");
buf.append(filterAssembler.getParameterDeclarations());
buf.append(" \n");
}
if (filterAssembler.hasVariableDeclarations())
{
buf.append("variable decl: ");
buf.append(filterAssembler.getVariableDeclarations());
buf.append(" \n");
}
}
return buf;
}
public List getVariables(Where where)
{
final List list = new ArrayList(1);
QueryVisitor visitor = new DefaultQueryVisitor() {
public void start(Variable var) {
list.add(var);
}
};
where.accept(visitor);
return list;
}
public void close() {
// TODO Auto-generated method stub
}
protected void log(Query root)
{
String xml = "";
PlasmaQueryDataBinding binding;
try {
binding = new PlasmaQueryDataBinding(
new DefaultValidationEventHandler());
xml = binding.marshal(root);
} catch (JAXBException e) {
log.debug(e);
} catch (SAXException e) {
log.debug(e);
}
log.debug("where: " + xml);
}
}
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