Stripes, Spring, JPA, Hibernate, struggling to tie them all together

[James Elsey]

Hi,

I've got an application with the above mentioned technologies, it seems to work great using a mock DAO to display my objects on the JSPs.

I've created a form pre-populated with some mock data, and I'm trying to persist this, but this is where I'm coming across a nullpointer and I have absolutely no idea why, I've followed lots of tutorials and have spent the whole day searching for an answer

ActionBean

   public class ViewClientAction extends BaseAction
{
    @SpringBean
    ClientService clientService = new ClientService();
    private Integer clientId;

    public void setClientId(Integer clientId)
    {
        this.clientId = clientId;
    }

    public Client getClient()
    {
        Client c = clientService.getClientById(clientId);
        return c;
    }

    @DefaultHandler
    public Resolution quickView()
    {
        return new ForwardResolution("/jsp/viewClientQuickView.jsp");
    }

    public Resolution save()
    {
        Client client2 = getClient();
        clientService.persistClient(client2);
        return new ForwardResolution("/jsp/reports.jsp");
    } 

Service

   @Service
public class ClientService
{

    ClientDao clientDao = new ClientMock();

    public List<Client> fetchClients()
    {

        return clientDao.fetchClients();
    }
    public Client getClientById(Integer clientId)
    {
        return clientDao.getClientById(clientId);
    }

    public void persistClient(Client client)
    {
        clientDao.persistClient(client);
    }
} 

Dao Implementation

   @Repository("clientDao")
public class ClientMock implements ClientDao
{
...


public void persistClient(Client client)
    {
        Stripersist.getEntityManager().persist(client);
    }
...


 

persistence.xml

   <persistence xmlns="http://java.sun.com/xml/ns/persistence"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
      http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
   version="1.0" >
    <persistence-unit name="stripes" transaction-type="RESOURCE_LOCAL">
      <!-- Tell JPA to use Hibernate -->
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
      <!-- Hibernate settings -->
        <properties>
        <!-- Autodetect entity classes -->
            <property name="hibernate.archive.autodetection" value="class"/>
        <!-- Automatically create the SQL schema -->
            <property name="hibernate.hbm2ddl.auto" value="create"/>
      <!-- Tell Hibernate to use HSQLDB -->
            <property name="hibernate.dialect"
        value="org.hibernate.dialect.HSQLDialect" />
            <property name="hibernate.connection.driver_class"
        value="org.hsqldb.jdbcDriver" />
      <!-- Configure the JDBC database connection -->
            <property name="hibernate.connection.url" value="jdbc:hsqldb:mem" />
            <property name="hibernate.connection.username" value="sa"/>
            <property name="hibernate.connection.password" value=""/>
            <property name="jdbc.batch_size" value="0"/>
      <!-- Configure the connection pool -->
            <property name="hibernate.c3p0.min_size" value="5"/>
            <property name="hibernate.c3p0.max_size" value="20"/>
            <property name="hibernate.c3p0.timeout" value="300"/>
            <property name="hibernate.c3p0.max_statements" value="50"/>
            <property name="hibernate.c3p0.idle_test_period" value="3000"/>
        </properties>
    </persistence-unit>
</persistence>
 

In my MockDAO I return a list of my objects which I use to display on my JSPs, what I've done is setup a form pre-populated with one of those objects, then I'm clicking a "save" button which should (via the service) invoke the .persist() on that object.

I've got all my hibernate / HSQLDB jars etc on the classpath, but I haven't explicitly done anything with HSQLDB as I wasn't aware I need to

Where am I going wrong?

[James Elsey]

The Stripersist.getEntityManager().persist(client); on my daoImplementation is giving me a nullPointer

[David Newton]

Where's the stack trace?

[James Elsey]

  SEVERE: StandardWrapperValve[DispatcherServlet]: PWC1406: Servlet.service() for servlet DispatcherServlet threw exception
java.lang.NullPointerException
        at com.jameselsey.salestracker.mockDao.ClientMock.persistClient(ClientMock.java:274)
        at com.jameselsey.salestracker.service.ClientService.persistClient(ClientService.java:28)
        at com.jameselsey.salestracker.action.ViewClientAction.save(ViewClientAction.java:41)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:616)
        at net.sourceforge.stripes.controller.DispatcherHelper$6.intercept(DispatcherHelper.java:442)
        at net.sourceforge.stripes.controller.ExecutionContext.proceed(ExecutionContext.java:158)
        at net.sourceforge.stripes.controller.BeforeAfterMethodInterceptor.intercept(BeforeAfterMethodInterceptor.java:113)
        at net.sourceforge.stripes.controller.ExecutionContext.proceed(ExecutionContext.java:155)
        at net.sourceforge.stripes.controller.ExecutionContext.wrap(ExecutionContext.java:74)
        at net.sourceforge.stripes.controller.DispatcherHelper.invokeEventHandler(DispatcherHelper.java:440)
        at net.sourceforge.stripes.controller.DispatcherServlet.invokeEventHandler(DispatcherServlet.java:278)
        at net.sourceforge.stripes.controller.DispatcherServlet.service(DispatcherServlet.java:160)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:847)
        at org.apache.catalina.core.ApplicationFilterChain.servletService(ApplicationFilterChain.java:431)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:337)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:218)
        at net.sourceforge.stripes.controller.StripesFilter.doFilter(StripesFilter.java:247)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:250)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:218)
        at org.apache.catalina.core.StandardWrapperValve.preInvoke(StandardWrapperValve.java:460)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:139)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:186)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:719)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:657)
        at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:96)
        at com.sun.enterprise.web.PESessionLockingStandardPipeline.invoke(PESessionLockingStandardPipeline.java:98)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:187)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:719)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:657)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:651)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1030)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:142)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:719)
        at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:657)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:651)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:1030)
        at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:325)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:242)
        at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:180)
        at com.sun.grizzly.http.DefaultProcessorTask.invokeAdapter(DefaultProcessorTask.java:633)
        at com.sun.grizzly.http.DefaultProcessorTask.doProcess(DefaultProcessorTask.java:570)
        at com.sun.grizzly.http.DefaultProcessorTask.process(DefaultProcessorTask.java:827)
        at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:152)
        at com.sun.enterprise.v3.services.impl.GlassfishProtocolChain.executeProtocolFilter(GlassfishProtocolChain.java:71)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:103)
        at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:89)
        at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:76)
        at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:67)
        at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:56)
        at com.sun.grizzly.util.WorkerThreadImpl.processTask(WorkerThreadImpl.java:325)
        at com.sun.grizzly.util.WorkerThreadImpl.run(WorkerThreadImpl.java:184)  

I've set breakpoints on the .persist() and the object that its trying to persist is there and valid, so that part shouldn't be causing the nullpointer

Thanks

[David Newton]

Then I'd assume there's no entity manager, assuming that's why you included that bit of code. How does Stripes expect you to create that?

[James Elsey]

yeah, my entityManager is null, but I'm not sure how to initialise it

Thanks

[Gregg Bolinger]

Stripersist should handle creating the entitymanager for you. There is an interceptor in the library that does this and opens and commits sessions for each page request. You'd probably be better off asking Stripersist specific questions on the Stripes mailing list since that is where the project author(s) hangs out.

Now, on for a very opinionated piece of information. You're already using Spring and Hibernate. I love Stripes. But considering your stack, I feel you'd be better off using Grails if you can. It uses Spring and Hibernate as well. It just makes things TONS easier.