[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Null Pointer when trying to use my persistent class
- To: Ozone <ozone-users@ozone-db.org>
- Subject: Null Pointer when trying to use my persistent class
- From: Neil Aggarwal <neil@JAMMConsulting.com>
- Date: Sat, 11 Nov 2000 18:55:50 -0500
- Delivered-To: softw7-ozone-db:org-ozone-users@ozone-db.org
Hello:
I am getting a Null Pointer exception when I try to add a
String object to a database class of mine. Ozone is
apparently creating my database and the persistent object
fine. It just dies when I try to manipulate the object.
Here is the output I am getting:
org.ozoneDB.OzoneInternalExc: java.lang.NullPointerException
at org.ozoneDB.ExternalDatabase.sendCommand(ExternalDatabase.java:324)
at org.ozoneDB.ExternalDatabase.sendCommand(ExternalDatabase.java:296)
at org.ozoneDB.ExternalDatabase.createObject(ExternalDatabase.java:413)
at org.ozoneDB.ExternalDatabase.createObject(ExternalDatabase.java:407)
at OzoneTest.<init>(OzoneTest.java:39)
at OzoneTest.main(OzoneTest.java:50)
Exception in thread "main"
Here is the code for my main class (OzoneTest.java):
import java.io.*;
import org.ozoneDB.*;
import persistent.*;
public class OzoneTest {
public static final String DB_DIR = "/Java/OzoneTest/Database";
public OzoneTest() throws Exception {
System.out.println(getClass().getName()+" starting.");
// Create a local database instance
LocalDatabase db = new LocalDatabase();
// Try to open the database
try {
System.out.println( "Opening database" );
db.open(DB_DIR);
} catch(Exception e ) {
// No database found, create one.
System.out.println( "No database found, creating one." );
db.create(DB_DIR);
// Try to open the database
db.open(DB_DIR);
}
// Create a person info object
PersonInfo2 personInfo = (PersonInfo2)
db.createObject(PersonInfo2Impl.class.getName(),
OzoneInterface.Public, "PersonInfo2");
personInfo.addToNames("ZZZZ");
personInfo.addToNames("AAA");
personInfo.addToNames("JJHS");
System.out.println(getClass().getName()+" finished.");
}
public static void main(String[] args) throws Exception {
OzoneTest ozoneTest = new OzoneTest();
}
}
Here is the code for my persistent class:
Here is the Interface (persistent/PersonInfo2.java):
package persistent;
import java.util.*;
import org.ozoneDB.*;
public interface PersonInfo2 extends OzoneRemote {
public void setName( String name );
public String getName();
public void addToNames(String name);
public Vector getNames();
}
Here is the implementation (persistent/PersonInfo2Impl.java):
package persistent;
import java.util.*;
import org.ozoneDB.*;
public class PersonInfo2Impl extends OzoneObject implements PersonInfo2
{
private String name;
private Vector names;
public void setName(String name) {
this.name = name;
}
public String getName() {
return name;
}
public String toString() {
return "PersonInfo for "+getName();
}
public void addToNames(String name) {
if( names == null )
names = new Vector();
names.add(name);
}
public Vector getNames() {
return names;
}
}
Here is what I used to generate the proxy:
opp -ks -p"(set*|addTo*|removeFrom*)" -opersistent
persistent.PersonInfo2Impl
The PersonInfo2Impl_Proxy looks OK and it compiled just fine.
Any ideas??
Thanks,
Neil.
--
Neil Aggarwal, President & CEO
JAMM Consulting, Inc. -- (972) 612-6056, http://www.JAMMConsulting.com
Custom Programming in Java, C++, HTML, perl