Problem in casting a database object to Java object

Question

hi everyone,
Iam trying to execute following example which was provided in oracle documentation. iam planning to implement this concept in my project...But, i am not able to run...iam herewith enclosing the sample code and its error...Kindly help me out
import java.sql.*;
import java.io.*;
import java.util.*;
import java.math.BigDecimal;
import oracle.sql.*;
import oracle.jdbc.*;
public class PersonObject
public static void main (String args [])
throws Exception
// Register the Oracle JDBC driver
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
// Connect to the database
// You need to put your database name after the @ sign in
// the connection URL.
// The sample retrieves an object of type "STUDENT",
// materializes the object as an object of type ADT.
// The Object is then modified and inserted back into the database.
Connection conn =
DriverManager.getConnection ("jdbc:oracle:thin:@raman.monsanto.com:1521:ramdevl","multispec", "mspec");
// It's faster when auto commit is off
conn.setAutoCommit (false);
// Create a Statement
Statement stmt = conn.createStatement ();
try
stmt.execute ("drop table people");
stmt.execute ("drop type PERSON FORCE");
stmt.execute ("drop type ADDRESS FORCE");
catch (SQLException e)
System.out.println("Error during executing a statement: "+ e);
stmt.execute ("create type ADDRESS as object (street VARCHAR (30), num NUMBER)");
stmt.execute ("create type PERSON as object (name VARCHAR (30), home ADDRESS)");
stmt.execute ("create table people (empno NUMBER, empid PERSON)");
stmt.execute ("insert into people values(101, PERSON ('Greg', ADDRESS ('Van Ness', 345)))");
stmt.execute ("insert into people values(102, PERSON ('John', ADDRESS ('Geary', 229)))");
ResultSet rs = stmt.executeQuery ("select * from people");
System.out.println("This application works till extraction of data\n");
showResultSet (rs);
rs.close();
stmt.close();
conn.close();
public static void showResultSet (ResultSet rs)
throws SQLException
while (rs.next ())
ResultSetMetaData rsmd=rs.getMetaData();
System.out.println("the no of columns: "+rsmd.getColumnCount());
for(int i=0;i<rsmd.getColumnCount();i++)
System.out.println("The column no "+(i+1)+"is of type: "+rsmd.getColumnTypeName(i+1) );
int empno = rs.getInt (1);
// retrieve the STRUCT
(This line throws the error----->) STRUCT person_struct = (STRUCT)rs.getObject (2);
Object person_attrs[] = person_struct.getAttributes();
System.out.println ("person name: " + (String) person_attrs[0]);
STRUCT address = (STRUCT) person_attrs[1];
System.out.println ("person address: ");
Object address_attrs[] = address.getAttributes();
System.out.println ("street: " + (String) address_attrs[0]);
System.out.println ("number: " +
((BigDecimal) address_attrs[1]).intValue());
System.out.println ();
The error message is as follows:
sj -make -cdb newmodeltest.cdb -g -d D:\VisualCafe\Projects\ -classpath
D:\jdk1.3\jre\lib\classes12.zip;D:\VisualCafe\Projects\;D:\VISUALCAFE\JAVA\LIB\;D:\VISUALCAFE\JAVA\LIB\SYMCLASS.ZIP;D:\VISUALCAFE\JAVA\LIB\CLASSES.ZIP;D:\VISUALCAFE\JFC\SWINGALL.JAR;D:\VISUALCAFE\swing
-1.1\SWINGALL.JAR;D:\VISUALCAFE\JAVA\LIB\RT.JAR;D:\VISUALCAFE\BIN\COMPONENTS\SFC.JAR;D:\VISUALCAFE\BIN\COMPONENTS\SYMBEANS.JAR;D:\VISUALCAFE\JAVA\LIB\icebrowserbean.jar;D:\VISUALCAFE\JAVA\LIB\jsdk.jar;
D:\VISUALCAFE\JAVA\LIB\SYMTOOLS.JAR;D:\VISUALCAFE\BIN\COMPONENTS\TEMPLATES.JAR D:\VisualCafe\Projects\PersonObject.java
Build Successful
loading PersonObject.class for debugging...
PersonObject.class successfully loaded
This application works till extraction of data
the no of columns: 2
The column no 1is of type: NUMBER
The column no 2is of type: MULTISPEC.PERSON
java.lang.IncompatibleClassChangeError: class java.util.Hashtable does not implement interface java.util.Map
at oracle.sql.StructDescriptor.getClass(StructDescriptor.java:418)
at oracle.sql.STRUCT.toJdbc(STRUCT.java:365)
at oracle.jdbc.driver.OracleStatement.getObjectValue(OracleStatement.java:4195)
at oracle.jdbc.driver.OracleStatement.getObjectValue(OracleStatement.java:4123)
at oracle.jdbc.driver.OracleResultSetImpl.getObject(OracleResultSetImpl.java:401)
at PersonObject.showResultSet(PersonObject.java:106)
at PersonObject.main(PersonObject.java:54)
at symantec.tools.debug.MainThread.run(Agent.java:48)
Thanks in advance
Sudarshan.K

Answer 1

Since that implementation has existed since 1.2 and
the original post suggested that 1.3 was being used,I
don't see that a newer version would help any.That's not a good assumption. There could have been a
bug fix.
Could be. But for the particular error (IncompatibleClassChangeError) I would consider the chance almost non-existent until all other possibilities have been exhausted.