Amol Chavan

Hi All Ranchers,

I am stuck with JSF's ValueChangeListener......Can anyone help me out of it?
I have a combo box (h:selectOneMenu) for which I used valuechangelistener to get to know whenever user changes the value and selects new option.
Here is the code:

<td width="35%"> <h:selectOneMenu immediate="true" id="txtDocType" value="#{WCCCSearchBean.m_sDocumentType}" valueChangeListener="#{formaccessorbean.processValueChange}" styleClass="input"> <f:selectItems value="#{WCCCSearchBean.documentType_document}" id="doctype_doc"/> </h:selectOneMenu> </td> </tr> <tr> <td colspan="2" height="10"></td> <t:inputHidden id="hidFormName" value="#{formaccessorbean.formURL}" /> </tr>

Now my method specified in valuechangelistener has following implementation:

public void processValueChange(ValueChangeEvent event) throws AbortProcessingException,Exception { boolean isUpdated = false; PhaseId phaseId = event.getPhaseId(); if (phaseId.equals(PhaseId.ANY_PHASE)){ if(event.getComponent().getId().equals("txtDocType")){ if (null != event.getNewValue()) { System.out.println("new value: "+event.getNewValue().toString()); this.setDocType(event.getNewValue().toString()); } } }

Also whatever value I am setting for [B]this.setDocType(event.getNewValue().toString());[/B],I am deciding which URL to be called and then passing this URL value to Javascript using hidden parameter which will take this URL and open a new window.

function openFormWindow(){ var formDownloadUrl = document.getElementById("inmate_Forms:hidFormName").value; alert("here: "+formDownloadUrl); window.open(formDownloadUrl); }

The problem is when I change the option and click submit button then it valuechangelistener works and on the console it shows the new option selected but I also have onclick event on submit which opens the new window for which URL comes from the bean.
But the roblem is it takes the old value from combo box even though it shows it has changed.What could be the reason?

Does it has to do something with Phases of JSF?

But I have written in the code that for 'ANY_PHASE' it will update the value.
But it still gives me the same problem.

Please help me!!!

Thanks in advance

[ August 21, 2007: Message edited by: Amol Chavan ]
[ August 21, 2007: Message edited by: Amol Chavan ]

Hi Chris Nappin,
I also want to implement the same functionality.are you through with this?
Can you guide me in this case?

Thanks in advance.

Hello All,

I want to know about how to sign documents usung Java.Though there is Java Security API for this, but my requirement is something like this as follows:

We will be having electronic pdf forms which user will access from the web application and user will fill theses forms and then save it.It will be saved to the application's corresponing directory but before saving these forms they must be digitally signed and certified so that no one can change it again.
However it should have all these features.
1.Corporate key signing � for all forms and documents at the time of saving of forms or documents.
2.Multi-user signing
3.Multi-user signing on the client-side using local keys and certificates
4.Adding handwritten signature along with the digital signature

Does anybody knows about any opensource or any other product or application that supports all this?

Please reply soon.

Thanks in advance.

I have dowloaded latest version of JBoss (JBoss 4.05GA) and Axis2 and deployed axis2.war file in Tomcat 5.5 as well as in JBoss 4.05.
In both application server application is running fine but in JBoss it is throwing strange exception on console but still it is not affecting application.
Guys can you help on this as I am new to Webservices and Axis.

Exception is as follows:

13:31:58,651 WARN [UDP] packet from /192.168.133.89:1153 has different version (0227?) from ours (02271). This may cause problems
13:31:58,651 ERROR [UDP] exception=java.io.StreamCorruptedException: invalid stream header
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:753)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:268)
at org.jgroups.protocols.UDP.handleIncomingUdpPacket(UDP.java:670)
at org.jgroups.protocols.UDP$IncomingPacketHandler.run(UDP.java:1332)
at java.lang.Thread.run(Thread.java:595)

Though application is running fine, the above mentioned exception is being thrown by application continuously when deployed on JBoss 4.05 while in tomcat 5.5 its running without such exception.

Please help if you know the reason.

yes, i am using <f:subview> to include other jsp file and that file has navigation menu which is command links to navigate form one screen to other.
but still its giving the problem.

Can you suggest a solution for it?
what could be the reason for it?

Hi All,

I am facing a javascript error due to JSF.Actually in my code I included a file in another file before starting a form tag of the file.
Now the problem is that whenever JSF page renders it creates a function called clear_formName() in the page and on every components which has some action or javascript function called on it, it also calls this function along with it.
But in my case it is not creating this function while rendering and still calling it while I click on the button due to which I am getting Javascript error and button not able to perform further action.But it is still creating this fuction with name like clear_linkDummyFoorm which is other than one used in my form.In the included file there is no form in it.
Due to this button is not of use and cannot execute action because of javascript error which says clear_frmPrint not defined.

Please help me it is urgent as I have to release it for testing and suddenly I got stuck with this error.

Hi all,

Instead of giving such replies please prvovide me some solution.
Java Print APIs are helpful for this and I'm using the same but the problem is DocFlavor that I used is not able to match with the printer's requirement.So I used DocFlavor (http://java.sun.com/j2se/1.5.0/docs/api/) as Printable but it did not work.
Can anybody tell me is there any way to pick up files and put it into printer's printing queue? Is there any opensource in java available for this?

Please reply asap.

HI,

Now I am able to select printer but not able to print contents of the file.
Can anyone tell me how to print a file/report using java print api.
I used all kind of DocFlavors but it did not work.

Also I want to print contents of report which is lying on defferent server for which I will have a link with me (URL).
Can anybody tell me how to bring contents from that URL and write to a temporary file and then print out contents of this file without displaying it to user.
Or is there any way to print the contents of that URL directly to printer without displaying it to user.

Thanks in advance.

Thanks for reply,

But I cannot find any solution over there.
Actually I implemented some of the code sample that it has but of no use.
Can you give me any code sample which will generate a pop-up for selection of printer and confirmation of user.
This code is taking default service on network.
About which servlet you were talikng I cannot find any one at the link mentioned by you.

Please tell me if any code sample is there?

Hi All,

Here is one more problem I'm facing.
Actually requirement is such to print the document without opening that document.
How to do it using java?
I have one jsp which has button 'Print Report' on clicking of which reports are geneated and it is also on sepaerate server for which I have link through I can connect over there and display these reports.
But now these reports should not be displayed in stead on click of this button these all reports should get printed and before printing it should ask user confirmation to print erport as wll aprinter selection.
The later part of asking user confirmation and selecting printer can be done using javascript but what about printing document on clicking button without even opening the document in brower.(All are web-based here).

Please help me asap.

Hey Thanks for your reply.
But now my application is working.
It requires cglib-nodep-2.1_3.jar
along with Hibernate3.2.jar and Spring2.0.jar files.
No need of other cglib.jar file is required.
the above version of cglib solved the problem.

anyway Thanks for your help.

Thanks for reply.

Can you tell where can I get latest version of cglib2.0.jar
because I have old version which do not have
Enhancer.setInterceptDuringConstruction method
Also I tried it with cglib2.1.3.jar.
This version do not have org package

Hence it is giving following error:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: org/objectweb/asm/Type
Caused by: java.lang.NoClassDefFoundError: org/objectweb/asm/Type
at net.sf.cglib.core.TypeUtils.parseType(TypeUtils.java:180)
at net.sf.cglib.core.KeyFactory.<clinit>(KeyFactory.java:66)
at net.sf.cglib.proxy.Enhancer.<clinit>(Enhancer.java:69)
at org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:111)
at org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstantiate(CGLIBProxyFactory.java:43)
at org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFactory(PojoEntityTuplizer.java:162)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
at org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
at org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping.<init>(EntityEntityModeToTuplizerMapping.java:56)
at org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:269)
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:425)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:109)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1218)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:807)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:740)
at org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:131)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1062)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1029)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:420)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:245)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:141)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:242)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:156)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:287)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:348)
at org.springframework.web.context.support.AbstractRefreshableWebApplicationContext.refresh(AbstractRefreshableWebApplicationContext.java:156)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:246)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:184)
at org.springframework.web.context.ContextLoaderServlet.init(ContextLoaderServlet.java:83)
at javax.servlet.GenericServlet.init(GenericServlet.java:211)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1029)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:862)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4013)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4357)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:823)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:807)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:595)
at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:277)
at org.apache.catalina.core.StandardHost.install(StandardHost.java:832)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:701)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:432)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:983)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:349)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1091)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:789)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1083)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:478)
at org.apache.catalina.core.StandardService.start(StandardService.java:480)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:2313)
at org.apache.catalina.startup.Catalina.start(Catalina.java:556)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:287)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:425)


Please help me on this.

Hi All,

I am using Hibernate and Spring in my application and now I am upgrading my current application which is using Hibernate 2.1.7c to Hibernate 3.0
and Spring 1.2.8 to Spring 2.0.
I have done all necessary changes in .hbm.xml files, api imports and applicationContext.xml file but still it is giving me error which is as follows. I do not know whether error is from Hibernate side or Spring side so I am posting it under both these topics.
Due to this it is not able to communicate with database and could not call HQL queries
Please help me :

Error:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.NoSuchMethodError: net.sf.cglib.proxy.Enhancer.setInterceptDuringConstruction(Z)V
Caused by: java.lang.NoSuchMethodError: net.sf.cglib.proxy.Enhancer.setInterceptDuringConstruction(Z)V
at org.hibernate.proxy.pojo.cglib.CGLIBLazyInitializer.getProxyFactory(CGLIBLazyInitializer.java:120)
at org.hibernate.proxy.pojo.cglib.CGLIBProxyFactory.postInstantiate(CGLIBProxyFactory.java:43)
at org.hibernate.tuple.entity.PojoEntityTuplizer.buildProxyFactory(PojoEntityTuplizer.java:162)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:135)
at org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:55)
at org.hibernate.tuple.entity.EntityEntityModeToTuplizerMapping.<init>(EntityEntityModeToTuplizerMapping.java:56)
at org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:269)
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:425)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:109)
at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55)
at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:226)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1218)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:807)
at org.springframework.orm.hibernate3.LocalSessionFactoryBean.buildSessionFactory(LocalSessionFactoryBean.java:740)
at org.springframework.orm.hibernate3.AbstractSessionFactoryBean.afterPropertiesSet(AbstractSessionFactoryBean.java:131)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1062)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1029)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:420)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:245)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:141)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:242)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:156)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:287)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:348)
at org.springframework.web.context.support.AbstractRefreshableWebApplicationContext.refresh(AbstractRefreshableWebApplicationContext.java:156)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:246)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:184)
at org.springframework.web.context.ContextLoaderServlet.init(ContextLoaderServlet.java:83)
at javax.servlet.GenericServlet.init(GenericServlet.java:211)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1029)
at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:862)
at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4013)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4357)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:823)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:807)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:595)
at org.apache.catalina.core.StandardHostDeployer.install(StandardHostDeployer.java:277)
at org.apache.catalina.core.StandardHost.install(StandardHost.java:832)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:701)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:432)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:983)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:349)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1091)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:789)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1083)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:478)
at org.apache.catalina.core.StandardService.start(StandardService.java:480)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:2313)
at org.apache.catalina.startup.Catalina.start(Catalina.java:556)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:287)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:425)

2006-11-08 11:18:04 StandardContext[/servlets-examples]ContextListener: contextInitialized()
2006-11-08 11:18:04 StandardContext[/servlets-examples]SessionListener: contextInitialized()

Please help me.
applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>
<!-- ========================= Start of PERSISTENCE DEFINITIONS ========================= -->

<!-- DataSource Definition -->
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName">
<value>oracle.jdbc.driver.OracleDriver</value>
</property>
<property name="url">
<value>jdbc racle:thin:@Orion:1521:LRSQA</value>
</property>
<property name="username">
<value>lrs</value>
</property>
<property name="password">
<value>lrs</value>
</property>
</bean>

<!-- Hibernate SessionFactory Definition -->
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="mappingResources">
<list>
<value>com/chenoa/lrs/model/businessobject/Policy.hbm.xml</value>
<value>com/chenoa/lrs/model/businessobject/ScheduleInforce.hbm.xml</value>
<value>com/chenoa/lrs/model/businessobject/ScheduleExpired.hbm.xml</value>
</list>
</property>

<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.Oracle9Dialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.cglib.use_reflection_optimizer">true</prop>
<prop key="hibernate.cache.provider_class">org.hibernate.cache.NoCacheProvider</prop>
</props>
</property>

<property name="dataSource">
<ref bean="dataSource"/>
</property>
</bean>

<!-- Spring Data Access Exception Translator Defintion -->
<bean id="jdbcExceptionTranslator" class="org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator">
<property name="dataSource"><ref bean="dataSource"/></property>
</bean>

<!-- Hibernate Template Defintion -->
<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
<property name="sessionFactory"><ref bean="sessionFactory"/></property>
<property name="jdbcExceptionTranslator"><ref bean="jdbcExceptionTranslator"/></property>
</bean>


<bean id="PolicyDao" class="com.chenoa.lrs.model.dao.hibernate.PolicyDaoHibernateImpl">
<property name="hibernateTemplate"><ref bean="hibernateTemplate"/></property>
</bean>

<bean id="ScheduleInforceDao" class="com.chenoa.lrs.model.dao.hibernate.ScheduleInforceDaoHibernateImpl">
<property name="hibernateTemplate"><ref bean="hibernateTemplate"/></property>
</bean>

<bean id="ScheduleExpiredDao" class="com.chenoa.lrs.model.dao.hibernate.ScheduleExpiredDaoHibernateImpl">
<property name="hibernateTemplate"><ref bean="hibernateTemplate"/></property>
</bean>


<!-- ========================= Start of SERVICE DEFINITIONS ========================= -->

<!-- Hibernate Transaction Manager Definition -->
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory"><ref local="sessionFactory"/></property>
</bean>

<!-- For policy service -->
<bean id="policyServiceTarget" class="com.chenoa.lrs.model.service.impl.CachedPolicyServiceImpl" init-method="init">
<property name="policyDao"><ref local="PolicyDao"/></property>
<property name="scheduleInforceDao"><ref local="ScheduleInforceDao"/></property>
<property name="scheduleExpiredDao"><ref local="ScheduleExpiredDao"/></property>
</bean>

<!-- Transactional proxy for the Policy Service -->
<bean id="policyService" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="transactionManager"><ref local="transactionManager"/></property>
<property name="target"><ref local="policyServiceTarget"/></property>
<property name="transactionAttributes">
<props>
<prop key="get*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="save*">PROPAGATION_REQUIRED</prop>
<prop key="update*">PROPAGATION_REQUIRED</prop>
<prop key="delete*">PROPAGATION_REQUIRED</prop>
</props>
</property>
</bean>

</beans>

Hi All,

I have a doubt related to inheritance in Java.
I have a Class DBOperation.java extends Scema.java.
Schema.java is created runtime and it has all the info about the tables and its

columns and field types, etc.
As more no of tables in the database size of Schema.java is getting bigger &

bigger which is creating problem at the time of compilation.

So i wrote a code which will create two files at runtime like Schema1.java which will have info of first 50 table and Schema2.java which will have info of next 50 tables.
But the problem here is DBOperation is extending Schema.java class so now which class it should extend?

I tried like this:

DBOperation extends Schema2

Schema2 extends Schema1

DBOperation call getTableInfo(tableName) method of its superclass which return HashMap with all the info of the table which is passed to that method.

public HashMap getTableInfo(tableName) is present in both Schema1.java as well Schema2.java.

but then it is giving NullPointer Exception when DBOpereation getting information of tables which is not in Schema2 but present in Schema1.

If it is getting null from Schema2 then it must check it in Schema1.java
How inheritance will help in this case?

Is there any other way to do it?

How to solve this problem?
Please help me.....

Thanks a lot,
Lynette Dawson
It really helped me and issue is resolved now.

Once again thanks for your help.