Java Object Cache have wired behaviour

HI,
I am trying to get my Oracle Java Object Cache working but I am observing some really stange behaviour which has stop it working. So any help will be really useful (10.1.3 and 10.1.2.0.2). I will explain:
Progammaticly I have setup a parent region call 'DatabaseDataCache' and a sub-region call 'country'. In this region I have defined my object call countriesDto' with a Attribuite that has a CaheLoader attached. In my cache loader I connects to a Entity EJB that loads a bunch of DTOs into the cache.
What is strange is that when i run the unit test on the code (cactus). The cache seems to call the cache loader 3 times consequtively before the EJB will load the data (i know this due to debuging messages)
Then in the actual implmentation I have the cache setup code of the in the init() of the servlet but again the cache loader doesn't seem to able to call the ejb it requires. Ones the cache is access it trys to call the cache loader and of course the ejb dosn't get called and is returning me a NullPointerError as I am trying to acces the local interface (in the cache loader). This is strange as in the cactus test it actually calls the ejb ok bit only on the third attemp.
I am abit puzzled with this so any help will be much appreciated.
Charlie

I think I have got what you need. The following is the cactus test class that test the getCountries method in my session ejb:
public class WebinUtilTest extends ServletTestCase {
private CacheAccess globParCache;
public void setUp() throws Exception {
CacheAccess.defineRegion("DatabaseDataCache");
globParCache = CacheAccess.getAccess("DatabaseDataCache");
globParCache.defineSubRegion("country");
Attributes cAtt = new Attributes();
cAtt.setLoader(new CountryCacheLoader());
CacheAccess globCountCache = globParCache.getSubRegion("country");
globCountCache.defineObject("countriesDto", cAtt);
globCountCache.preLoad("countriesDto");
globCountCache.close();
globParCache.close();
public void testGetCountries() throws Exception{
WebinUtilLocal wuLoc = HomeFactory.getWebinUtilLocalHome().create();
String[] countries = wuLoc.getCountries();
assertTrue(countries.length >0);
public void tearDown() throws Exception {
if (globParCache != null){
CacheAccess gCache = CacheAccess.getAccess("DatabaseDataCache");
gCache.destroy();
When I run this test here is the stack trace I am getting (in order):
06/01/05 15:54:14 load entred for country cache loader: Thu Jan 05 15:54:14 GMT 2006
06/01/05 15:54:14 java.lang.Exception: Stack trace
06/01/05 15:54:14 at java.lang.Thread.dumpStack(Thread.java:1064)
06/01/05 15:54:14 at uk.ac.ebi.submission.util.CountryCacheLoader.load(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheLoader.callLoad(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.findObject(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.asyncLoad(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.Task.execute(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.WorkerThread.run(Unknown Source)
06/01/05 15:54:14 WebinUtil Session Started: Thu Jan 05 15:54:14 GMT 2006
06/01/05 15:54:14 load entred for country cache loader Thu Jan 05 15:54:14 GMT 2006
06/01/05 15:54:14 java.lang.Exception: Stack trace
06/01/05 15:54:14 at java.lang.Thread.dumpStack(Thread.java:1064)
06/01/05 15:54:14 at uk.ac.ebi.submission.util.CountryCacheLoader.load(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheLoader.callLoad(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.findObject(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheHandle.locateObject(Unknown Source)
06/01/05 15:54:14 at oracle.ias.cache.CacheAccess.get(Unknown Source)
06/01/05 15:54:14 at uk.ac.ebi.submission.ejb.session.WebinUtilBean.getCountries(Unknown Source)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
06/01/05 15:54:14 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
06/01/05 15:54:14 at java.lang.reflect.Method.invoke(Method.java:324)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.EJBJoinPointImpl.invoke(EJBJoinPointImpl.java:39)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:45)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:62)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.JAASInterceptor$1.run(JAASInterceptor.java:32)
06/01/05 15:54:14 at java.security.AccessController.doPrivileged(Native Method)
06/01/05 15:54:14 at javax.security.auth.Subject.doAs(Subject.java:379)
06/01/05 15:54:14 at com.evermind.server.ThreadState.runAs(ThreadState.java:637)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.JAASInterceptor.invoke(JAASInterceptor.java:36)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.TxRequiredInterceptor.invoke(TxRequiredInterceptor.java:56)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.SecurityRoleInterceptor.invoke(SecurityRoleInterceptor.java:46)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.DMSInterceptor.invoke(DMSInterceptor.java:62)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.system.RunningStateInterceptor.invoke(RunningStateInterceptor.java:28)
06/01/05 15:54:14 at com.evermind.server.ejb.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:43)
06/01/05 15:54:14 at com.evermind.server.ejb.StatelessSessionEJBObject.OC4J_invokeMethod(StatelessSessionEJBObject.java:106)
06/01/05 15:54:14 at WebinUtilLocal_StatelessSessionBeanWrapper50.getCountries(WebinUtilLocal_StatelessSessionBeanWrapper50.java: 310)
06/01/05 15:54:14 at uk.ac.ebi.submission.cactus.session.WebinUtilTest.testGetCountries(Unknown Source)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
06/01/05 15:54:14 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
06/01/05 15:54:14 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
06/01/05 15:54:14 at java.lang.reflect.Method.invoke(Method.java:324)
06/01/05 15:54:14 at junit.framework.TestCase.runTest(TestCase.java:154)
06/01/05 15:54:14 at junit.framework.TestCase.runBare(TestCase.java:127)
06/01/05 15:54:14 at org.apache.cactus.internal.AbstractCactusTestCase.runBareServer(AbstractCactusTestCase.java:153)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestCaller.doTest(AbstractWebTestCaller.java:119)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestController.handleRequest_aroundBody0(AbstractWebTestControl ler.java:93)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestController.handleRequest_aroundBody1$advice(AbstractWebTest Controller.java:224)
06/01/05 15:54:14 at org.apache.cactus.internal.server.AbstractWebTestController.handleRequest(AbstractWebTestController.java)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doPost_aroundBody2(ServletTestRedirector.java:101)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doPost_aroundBody3$advice(ServletTestRedirector.java:224)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doPost(ServletTestRedirector.java)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doGet_aroundBody0(ServletTestRedirector.java:72)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doGet_aroundBody1$advice(ServletTestRedirector.java:224)
06/01/05 15:54:14 at org.apache.cactus.server.ServletTestRedirector.doGet(ServletTestRedirector.java)
06/01/05 15:54:14 at javax.servlet.http.HttpServlet.service(HttpServlet.java:743)
06/01/05 15:54:14 at javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
06/01/05 15:54:14 at com.evermind.server.http.ResourceFilterChain.doFilter(ResourceFilterChain.java:64)
06/01/05 15:54:14 at oracle.security.jazn.oc4j.JAZNFilter.doFilter(JAZNFilter.java:382)
06/01/05 15:54:14 at com.evermind.server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:701)
06/01/05 15:54:14 at com.evermind.server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:397)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.doProcessRequest(HttpRequestHandler.java:833)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:430)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.serveOneRequest(HttpRequestHandler.java:216)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:119)
06/01/05 15:54:14 at com.evermind.server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketReadHandler$SafeRunnable.run(ServerSocketReadHandler.java:215)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketAcceptHandler.procClientSocket(ServerSocketAcceptHandler.java:232)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketAcceptHandler.access$1000(ServerSocketAcceptHandler.java:35)
06/01/05 15:54:14 at oracle.oc4j.network.ServerSocketAcceptHandler$AcceptHandlerHorse.run(ServerSocketAcceptHandler.java:819)
06/01/05 15:54:14 at com.evermind.util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:303)
06/01/05 15:54:14 at java.lang.Thread.run(Thread.java:534)
Hope this is enough information.
Thanks
Charlie

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Have one big file mapped to memory. I write the serialized objects to different portions of the file and then read those portions when needed. I can use the MappedByteBufferThis is a good idea, one that I have worked on. It involves quite a bit of manipulation with temporary buffers and a deep working knowledge of object serialization.
1. How do I delete things from the cache in the above design i.e. how do I delete portions of a mapped file?The best way to handle this is do a two-step process, cutting the file into two pieces and gluing it back together where the original one is...
2. How do I serialize objects using ByteBuffers and then deserialize them? I guess this shouldn't be hard but just want to confirm.It is hard. Wrapping the streams and making the IO work properly is not the challenge however. The hard part comes in hacking the object streams. The object input/output streams use a ClassDescriptor object which only gets written once/ read once. This shouldn't be a problem if you will read/write the entire file at once, but will bring you grief if you want random access to your objects. You will also need an indexing mechanism to support random access.
Do you think this is the right design or should I change? Right now using the old io package, I have a separate file for each object. When using the NIO package, I want to store all objects in a single file in different portions of the file, is that the right way to go?I guess it depends on your needs. Do you require random access to objects? NIO provides some performance gains, but mostly for very large amounts of data (>10M in my experience).
You can always write all your objects into the same file using normal io techniques and you can still generate an index and acheive random access. It might be easier...
Good luck

Code generation: from resultset to Java Object

Hello all:
Is there any utilities that can convert the ResultSet to a list of Java objects? I think that's doable, since we can get the metadata from ResultSetMetaData anyway, which provide a means to construct the internal properties of a java object.
I just wonder if there is already something doing that out there... rather not to reinvent the wheel...
Thanks,
John

thanks to both.
You don't create data objects from data rather your data exists within the data objects. Thus the code that is going to use the data objects must already know the form so they can do something intelligent in the first place.So much better to start with a data model and then create code from that then populate from the database.
>
Here I just explore the idea and assess its viability. The project is using a cache solution, coherence as matter of fact. it seems the idea is to return a data strcture like a generic resultset from the cache. my understanding is that, when a user sends out a SQL, the database designer wouldn't know the POJOs the user uses from their side, still database is able to return a resultset from which the user will have enough info to populate their POJOs.
I will take another look at the design, but meanwhile I found BasicDynaBean from apache's bean utilities useful, and came out with the following code:
public List<BasicDynaBean> execute(final RequestObject ro) throws SQLException {
          List<BasicDynaBean> list = jdbcTemplate.execute(
                    new CallableStatementCreator(){
                         @Override
                         public CallableStatement createCallableStatement(Connection con)
                                   throws SQLException {
                              CallableStatement cs = con.prepareCall(spName);
                                         // code skipped
                                                                                                return cs;
                    new CallableStatementCallback<List<BasicDynaBean>>(){
                         @Override
                         public List<BasicDynaBean> doInCallableStatement(CallableStatement cs)
                                   throws SQLException, DataAccessException {
                              cs.execute();
                              ResultSet rs = (ResultSet) cs.getObject(outputPos);
                                                                                                //apache api to convert the rs to list of BasicDynaBean
                              RowSetDynaClass rsdc = new RowSetDynaClass(rs);
                              List<BasicDynaBean> rows = rsdc.getRows();
                              return rows;
          however, I noticed that each mean contains the column headers, seems to me it's quite a overhead!
thanks, John
Edited by: Johnny_hunter on Aug 1, 2011 10:49 AM
Edited by: Johnny_hunter on Aug 1, 2011 11:57 AM

How to reload class file for java objects in CF MX7

I'm trying to create a simple java object for use in a CFML
page. According to the topic "About ColdFusion and Java objects" in
the CF developer's guide, I can compile my java module and put the
.class file in the CFusionMX7/wwwroot/WEB-INF/classes directory and
it'll be dynamically reloaded any time CF sees a new .class file
there. But the dynamic reload isn't happening; I have to restart
the CF server to get it to pick up a new version.
I don't believe this directory is in the "general JVM
classpath"; I don't find "classes" in the Java Class Path in the CF
Administrator's System Information page. And I have all the caching
options turned off on the "Server Settings > Caching" page, if
that has any bearing on it.
Are there any known issues around this dynamic reload
capability, or maybe a more definitive way to make sure the
WEB-INF/classes directory isn't in the classpath?
Thanks,
James

Yes, I understand. But if I'm reading it correctly, what
you're saying seems to contradict the documentation
http://livedocs.adobe.com/coldfusion/7/htmldocs/00001561.htm
ColdFusion dynamically loads classes that are either .class
files in the web_root/WEB-INF/classes directory or in JAR files in
the web_root/WEB-INF/lib directory. ColdFusion checks the time
stamp on the file when it creates an object that is defined in
either directory, even when the class is already in memory. If the
file that contains the class is newer than the class in memory,
ColdFusion loads the class from that directory.
http://kb.adobe.com/selfservice/viewContent.do?externalId=tn_18228&sliceId=1
Dynamic class reloading for Java servlets classes and
forcfobject (sic) Java classes is disabled by default in
ColdFusion MX. To enable dynamic class reloading, do the following:
Also, I seem to recall that setting worked in a prior
version. Though I would have to test it again on another machine to
be certain.

OCI Object Cache leaking memory

I am performing a select that selects a column object (ie column of user defined type) from a table using OCI. It all works fine. However, the OCI client-side object cache just grows and grows and grows when this query is run regardless of the settings for ATTR_CACHE_MAX_SIZE and ATTR_CACHE_OPT_SIZE. I am not pinning the objects so there should be no reason why the cache should not age the objects out and free the memory. I see no such problems on non-object selects - the cache behaves fine unless I select object types (SQLT_NTY).
I can workaround the problem by calling OCICacheFree regularly - but I don't like the inelegance of that solution. If I don't do this however, OCI will cache and cache and cache until it has exhausted all the memory on my server !!
So anyone else see this problem ? Am I doing something wrong ? Is is an Oracle bug ?
Thanks for any help,
Steve

hi there,
i dunno if my problem is related to the above issue.
BUT.
Here is what I have:
- JBoss-3.2.1 running on Linux RedHat 9
- Oracle 9 running ... somewhere
Here is what I want:
- to regularly transfer big files from the client app thru JBoss/EJBs to Oracle
Here is what I tried:
- I tried BLOBs and CLOBs and etc. But the ARRAY choice appeared to be the best and has been working pretty fine till I started getting the problem I am gonna talk about here below.
Here is what I do (the code snippet of an EJB):
Connection conn = null;
CallableStatement stmt = null;
// some code
stmt = conn.prepareCall("begin SOME_PROCEDURE");
// some code
ArrayList data = new ArrayList();
ByteArrayInputStream is = new ByteArrayInputStream(fileContent);
ArrayDescriptor arrdesc = ArrayDescriptor.createDescriptor("RAW_VARRAY", ((JDCConnection)conn).getConnection());
ARRAY arr = new ARRAY(arrdesc, ((JDCConnection)conn).getConnection(), data.toArray());
((oracle.jdbc.OracleCallableStatement)stmt).setARRAY(2, arr);
// trying to execute the stmt
stmt.execute();
Where:
- RAW_ARRAY is a user-defined Oracle collection type. It is basically 'array[10240] of RAW'
- JDCConnection implements java.sql.Connection.
(JDCConnection was created to facilitate connection pooling inside JBoss, but I guess, yes I guess, that's not that relevant here).
Here is the PROBLEM:
- the code works pretty fine for a while
- BUT after some time, the code starts dumping the following exception:
java.sql.SQLException: OCI-21522: attempted to use an invalid connection in OCI (object mode only)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:169)
at oracle.jdbc.oci8.OCIDBAccess.check_error(OCIDBAccess.java:1609)
at oracle.jdbc.oci8.OCIDBAccess.getOracleTypeADT(OCIDBAccess.java:1745)
at oracle.jdbc.oracore.OracleTypeADT.initMetadata(OracleTypeADT.java:386)
at oracle.jdbc.oracore.OracleTypeADT.init(OracleTypeADT.java:344)
at oracle.sql.ArrayDescriptor.initPickler(ArrayDescriptor.java:1002)
at oracle.sql.ArrayDescriptor.<init>(ArrayDescriptor.java:132)
at oracle.sql.ArrayDescriptor.createDescriptor(ArrayDescriptor.java:97)
Can anybody let me know if you have any ideas of what's going on here?
Your help is badly needed, guys!
Many thx in advance!!
my best,
Kanat.

Generation of XML file from Java objects using castor

I have the following java file(Customer.java).
public class Customer
     private String ID;
     private FirstName firstName;
     private MiddleName middleName;
     private LastName lastName;
     private ArrayList address;
     public ArrayList getAddress() {
          return address;
     public void setAddress(ArrayList address) {
          this.address = address;
     public FirstName getFirstName() {
          return firstName;
     public void setFirstName(FirstName firstName) {
          this.firstName = firstName;
     public String getID() {
          return ID;
     public void setID(String id) {
          ID = id;
     public LastName getLastName() {
          return lastName;
     public void setLastName(LastName lastName) {
          this.lastName = lastName;
     public MiddleName getMiddleName() {
          return middleName;
     public void setMiddleName(MiddleName middleName) {
          this.middleName = middleName;
Using castor i have created an xml file(customer.xml) which has the following format.
<?xml version="1.0" encoding="UTF-8" ?>
- <customer ID="fbs0001">
<FIRSTNAME>Fred</FIRSTNAME>
<MIDDLENAME>B</MIDDLENAME>
<LASTNAME>Scerbo</LASTNAME>
- <ADDRESS>
<FIRSTLINE>No 18, Sheshadri road</FIRSTLINE>
<SECONDLINE>Gandhinagar Bangalore</SECONDLINE>
</ADDRESS>
- <ADDRESS>
<FIRSTLINE>ITPL</FIRSTLINE>
<SECONDLINE>Whitefield Bangalore</SECONDLINE>
</ADDRESS>
</customer>
I have used a mapping file to get this output.Is there a way where i can get the output xml in the following format without changing the Java object structure.If yes then please suggest how this can be done.
<?xml version="1.0" encoding="UTF-8" ?>
- <customer ID="fbs0001">
<FIRSTNAME>Fred</FIRSTNAME>
<MIDDLENAME>B</MIDDLENAME>
<LASTNAME>Scerbo</LASTNAME>
</customer>
<ADDRESS>
<FIRSTLINE>No 18, Sheshadri road</FIRSTLINE>
<SECONDLINE>Gandhinagar Bangalore</SECONDLINE>
</ADDRESS>
- <ADDRESS>
<FIRSTLINE>ITPL</FIRSTLINE>
<SECONDLINE>Whitefield Bangalore</SECONDLINE>
</ADDRESS>
I mean the output xml file should have the address as a separate tag not withing the root tag customer.

Hello,
Castor's own discussion groups might be able to point you to the solution you're looking for (if this use case is possible using Castor).
Oracle has its own object-to-XML mapping tool that is part of the TopLink product. It allows you to map existing objects to an existing XML Schema. This can be done visually using the TopLink Workbench, or programmatically using the TopLink APIs. TopLink OXM also supports the JAXB specification.
Using TopLink OXM to get the desired XML result I would recommend the following. Map the Customer and Address classes to XML, but don't map the relationship between Customer and Address. Then make the calls to the marshaller something like the following:
marshaller.marshal(aCustomer, System.out);
for(int x=0; x<aCustomer.getAddress().size(); x++) {
     marshal(aCustomer.getAddress().get(x), System.out);
Example - Using TopLink OXM to map an existing object model to an existing XML Schema:
http://www.oracle.com/technology/products/ias/toplink/preview/10.1.3dp4/howto/ox/index.htm
For more information on TopLink object-to-XML mapping:
http://www.oracle.com/technology/products/ias/toplink/preview/10.1.3dp4/objectxml/index.html
-Blaise

Java Object Cache have wired behaviour

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