Is there any API tracing available?

Question

We are using Netscape LDAP JDK to write app programs which interact with
Directory Server (All vendors).
Is there any standard way of turning JDK tracing ON? Any examples will be
great.
Chet

Answer 1

Hi Prathap,
No, there is no Java API specific for RDF functionality available. However, Java client applications can use JDBC to access the RDF store. A partially relevant post is at How do you query Oracle RDF database using Java program? . The JDBC documentation will have detailed documentation on using JDBC.
Code snippets for one way of accessing SDO_RDF_MATCH through Java is below:
<..........>
sbStmt.append("select * from TABLE( ")
.append(" SDO_RDF_MATCH('(?S ?P ?O)',")
.append(" SDO_RDF_Models('")
.append( <model_name> )
.append("'),")
.append("null,null,null))")
.append(" where rownum <= ")
.append(iNumRows)
ResultSet rs = stmt.executeQuery(sbStmt.toString());
while (rs.next()) {
System.out.print("\n");
System.out.print(rs.getString("S"));
System.out.print(" (");
System.out.print(rs.getString("S$RDFVTYP"));
System.out.print(") ");
System.out.print(", ");
System.out.print(rs.getString("P"));
System.out.print(" (");
System.out.print(rs.getString("P$RDFVTYP"));
System.out.print(") ");
System.out.print(", ");
System.out.print(rs.getString("O"));
System.out.print(" (");
System.out.print(rs.getString("O$RDFVTYP"));
System.out.print(") ");
<............>
<...... handling CLOB values that are returned ....>
// read CLOB if applicable
Reader reader = null;
try {
CLOB clob = ((OracleResultSet) rs).getCLOB("O$RDFCLOB");
if (clob == null) {
System.out.print("not a long literal ");
else {
reader = clob.getCharacterStream();
char[] buffer = new char[1024];
// reading 1K at a time (just a demo)
int iLength = reader.read(buffer);
for (int i = 0; i < iLength; i++) {
System.out.print(buffer);
System.out.print(" ...");
finally {
if (reader != null) reader.close();
<..........>