Could not instantiate collection persister

Question

Hi I am consistently getting this error in my Struts2 hibernate application. Below is the stack trace for this error

    SEVERE: Could not instantiate collection persister org.hibernate.persister.collection.BasicCollectionPersister
org.hibernate.MappingException: Could not instantiate collection persister org.hibernate.persister.collection.BasicCollectionPersister
    at org.hibernate.persister.internal.PersisterFactoryImpl.create(PersisterFactoryImpl.java:242)
    at org.hibernate.persister.internal.PersisterFactoryImpl.createCollectionPersister(PersisterFactoryImpl.java:201)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:430)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1859)
    at projectBroomKetuActionDataItrfc.dto.HibernateUtility.getSessionFactory(HibernateUtility.java:19)
    at projectBroomKetuActionDataItrfc.dto.DatabaseInteractionInterface.checkDataDuplication(DatabaseInteractionInterface.java:60)
    at projectBroomKetuAction.SignUpActionClass.validate(SignUpActionClass.java:462)
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doBeforeInvocation(ValidationInterceptor.java:251)
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:263)
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:76)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:229)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at org.apache.struts2.interceptor.DateTextFieldInterceptor.intercept(DateTextFieldInterceptor.java:125)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:253)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:244)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:564)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:81)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:409)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1044)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 0
    at org.hibernate.persister.collection.AbstractCollectionPersister.generateSelectSizeString(AbstractCollectionPersister.java:1020)
    at org.hibernate.persister.collection.AbstractCollectionPersister.<init>(AbstractCollectionPersister.java:528)
    at org.hibernate.persister.collection.BasicCollectionPersister.<init>(BasicCollectionPersister.java:77)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at org.hibernate.persister.internal.PersisterFactoryImpl.create(PersisterFactoryImpl.java:231)
    ... 66 more

Below is hibernat.cfg.xml

<?xml version='1.0' encoding='utf-8'?> <!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

    <session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.url">jdbc:mysql://127.0.0.1:3306/b#%^^DB</property>


        <property name="connection.username">****</property>

        <property name="connection.password">******</property>



       <!-- JDBC connection pool (use the built-in) -->
        <!--   
        <property name="connection.pool_size">10</property>          -->        <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>         <property name="hibernate.c3p0.min_size">1</property>
        <property name="hibernate.c3p0.max_size">15</property>
        <property name="hibernate.c3p0.timeout">300</property>
        <property name="hibernate.c3p0.max_statements">50</property>
        <property name="hibernate.c3p0.idle_test_period">30</property>

                <!--  Connection testing settings -->

        <property name="hibernate.c3p0.validate">false</property>
        <property name="hibernate.c3p0.automaticTestTable">conTestTable</property> 

        <!--  
        <property name="hibernate.c3p0.timeout">600</property>
        <property name="hibernate.c3p0.maxIdleTimeExcessConnections">20</property>      -->
        <!--  Connection testing settings -->
        <!--
        <property name="hibernate.c3p0.validate">false</property>
        <property name="hibernate.c3p0.idle_test_period">30</property>
        <property name="hibernate.c3p0.automaticTestTable">conTestTable</property>
        -->
        <!-- SQL dialect -->
        <property name="dialect">projectBroomKetuDataClass.dto.ImprovedMySQLDialect</property>

        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

         <!-- Drop and re-create the database schema on startup -->         <property name="hbm2ddl.auto">update</property>         <mapping class="projectBroomKetuDataClass.dto.HouseHoldDetails"/>       <mapping class="projectBroomKetuDataClass.dto.MaidsDetails"/>       <mapping class="projectBroomKetuDataClass.dto.HouseHoldServiceReqMap"/>         <mapping class="projectBroomKetuDataClass.dto.MaidWeekTimeMap"/>        <mapping class="projectBroomKetuDataClass.dto.VerificationToken"/>      <mapping class="projectBroomKetuDataClass.dto.Services"/>       <mapping class="projectBroomKetuDataClass.dto.ServicesOffered"/>
                <mapping class="staff.CoordinatorDataClass.dto.CoordinatorDetails"/>        <mapping class="resource.dataClasses.dto.HouseKeeperDetails"/>      <mapping class="resource.dataClasses.dto.ElederCareTakerDetails"/>      <mapping class="resource.dataClasses.dto.DriverDetails"/>       <mapping class="resource.dataClasses.dto.CookDetails"/>         <mapping class="resource.dataClasses.dto.BabySitterDetails"/>
                <mapping class="services.dataClass.dto.BabySittingService"/>        <mapping class="services.dataClass.dto.CookingService"/>        <mapping class="services.dataClass.dto.DriverService"/>         <mapping class="services.dataClass.dto.ElderlyCareService"/>        <mapping class="services.dataClass.dto.HouseKeepingService"/>
    </session-factory>

</hibernate-configuration>

Below is the code snippet of my HibernateUtil class

public static final SessionFactory getSessionFactory() {
    if(null == sessionFactory)
    {
        //try{
            Configuration configuration = new Configuration();
            configuration.configure();
            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(
               configuration.getProperties()).build();

            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        //}
    //  catch(HibernateException ex){
        //  System.err.println("Initial SessionFactory creation failed." + ex);
         //  return null;
      // }     
     }
            return sessionFactory;
    }
}    

Please can anyone help me with this. I tried to find out why I am getting a

java.lang.ArrayIndexOutOfBoundsException: 0 at org.hibernate.persister.collection.AbstractCollectionPersister.generateSelectSizeString

But could not guess anything.

Edit:

I again looked into the source of exception and it is this code snippet.

protected String generateSelectSizeString(boolean isIntegerIndexed) {
        String selectValue = isIntegerIndexed ?
                "max(" + getIndexColumnNames()[0] + ") + 1" : // lists, arrays
                "count(" + getElementColumnNames()[0] + ")"; // sets, maps, bags
        return new SimpleSelect( dialect )
                .setTableName( getTableName() )
                .addCondition( getKeyColumnNames(), "=?" )
                .addColumn( selectValue )
                .toStatementString();
    }

now from the point where function generateSelectSizeString(boolean isIntegerIndexed) is called is this

 sqlSelectSizeString = generateSelectSizeString( collection.isIndexed() && !collection.isMap() );

Here isIndexed and isMap both always return false. So going back to method defination

protected String generateSelectSizeString(boolean isIntegerIndexed)

isIntegerIndexed = false

Hence the array out of bound exception is happening at this line

String selectValue = "count(" + getElementColumnNames()[0] + ")";

Again getElementColumnNames() returns a protected final String array elementColumnNames. which is alloted memory from inside the constructor of org.hibernate.persister.collection.AbstractCollectionPersister

at this line

int elementSpan = collection.getElement().getColumnSpan();
elementColumnNames = new String[elementSpan];

I am unable to see how getColumnSpan() works but it is definitely returning 0 and that is why when we access elementColumnNames[0] we get a array Out of bound exception. Does anyone know how the getColumnSpan() work.? I have again checked my code I don't think there is anything that hasn't been taken care of

Answer 1

Ok Solved It I had not written any field in one of the embeddable class because of which the column span was coming out to be 0. Which cause array index out of bound exception.` earlier it was like this

import javax.persistence.Embeddable;

@Embeddable
public class HouseKeeperSuggested {


}

Then I added a field

import javax.persistence.Embeddable;

@Embeddable
public class HouseKeeperSuggested {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

And problem solved