NullPointerException Cannot invoke "java.lang.Integer.intValue()"

I've a controller defined like this and getting a NullPointerException Cannot invoke "java.lang.Integer.intValue()" because "this.id" is null (some stack trace shown in the end - had to shorten it as it was exceeding 10k character limit)
while processing the form using Hibernate. By processing, I mean I'm using POST. Since this is first time I'm trying to insert a record, the table is empty so not sure why it's complaining about this.id is null.


@Controller @RequestMapping("/companyNewRecord") public class CompanyNewRecordController { private CompanyManager mgr; public void setUserManager(CompanyManager companyManager) { this.mgr = companyManager; } // display the form @RequestMapping(method = RequestMethod.GET) public ModelAndView edit(ModelAndView mav) { mav.setViewName("companyNewRecord"); mav.addObject("CompanyNewRecordForm", new CompanyNewRecordForm()); return mav; } // process the form @RequestMapping(method = RequestMethod.POST) public ModelAndView process(ModelAndView mav, @ModelAttribute("CompanyNewRecordForm") CompanyNewRecordForm CompanyNewRecordForm, BindingResult result) throws Exception { Company addNewCompany = new Company();        addNewCompany.setName(CompanyNewRecordForm.getCompanyName()); addNewCompany.setComment(CompanyNewRecordForm.getComment()); mgr.saveCompany(addNewCompany); return mav; } }


Here's my Company class inside com.pending.model:

public class Company implements Serializable{ private Integer id;        private String name;        private String comment; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getComment() { return comment; } public void setComment(String comment) { this.comment = comment; } }

My Company.hbm.xml file is also inside com.pending.model

CompanyManager interface inside com.pending.service is as follows:

public interface CompanyManager { public void setCompanyDAO(CompanyDAO dao); public Company getCompany(Integer id); public void saveCompany(Company company); }

CompanyDAO inside com.pending.dao

public interface CompanyDAO { public Company getCompany(Integer id); public Company saveCompany(Company company); }


CompanyDaoHibernate in com.pending.dao.hibernate

public class CompanyDAOHibernate extends HibernateDaoSupport implements CompanyDAO { @Override public Company saveCompany(Company company) { getHibernateTemplate().saveOrUpdate(company); if (logger.isDebugEnabled()) { logger.debug("Company id is: " + company.getId()); } return company; } @Override public Company getCompany(Integer id) { Company company = (Company) getHibernateTemplate().get(Company.class, id); if (company == null) { throw new ObjectRetrievalFailureException(Company.class, id); } return company; }


CompanyManagerImpl in com.pending.service.impl


public class CompanyManagerImpl implements CompanyManager { private CompanyDAO dao; public void setCompanyDAO(CompanyDAO dao) { this.dao = dao; } public void saveCompany(Company company) { dao.saveCompany(company); } public Company getCompany(Integer id) { return dao.getCompany(id); } }


The XML file is defined inside applicationContext-hibernate.xml as follows along with other xml files (not shown below)


<bean id="sessionFactoryCOMPANYDB" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean"> <property name="dataSource"> <ref bean="dataSourceCOMPANYDB" /> </property> <property name="mappingResources"> <list> <value>com/pending/model/Company.hbm.xml</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect"> org.hibernate.dialect.SQLServer2012Dialect </prop> <prop key="hibernate.show_sql">false</prop> <prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.SingletonEhCacheRegionFactory </prop> <prop key="hibernate.cache.use_second_level_cache">true</prop> </props> </property> </bean>

And applicationContex.xml contains the following bean :

<bean id="companyManager" parent="txProxyTemplateCOMPANYDB"> <property name="target"> <bean class="com.pending.service.impl.CompanyManagerImpl"> <property name="companyDAO"> <ref bean="companyDAO" /> </property> </bean> </property> </bean>


Here's Company.hbm.xml

   <?xml version="1.0" encoding="UTF-8"?>    <!DOCTYPE hibernate-mapping PUBLIC    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">    <hibernate-mapping>    <class name="com.pending.model.Company" table="company">    <id name="id" column="id" unsaved-value="null">    <generator class="native" />    </id>    <property name="name" />    <property name="comment" />    </class>    </hibernate-mapping>

SQLServer database table design is as follows:

Column Name    Data type       Allow Nulls
id                          int        
name                    varchar(10)
comment              varchar(50)    checkmarked

Where, id is set to primary key

Here is the stacktrace:
[INFO] [talledLocalContainer] org.springframework.orm.hibernate5.HibernateSystemException: Exception occurred inside getter of com.pending.model.Company.id; nested exception is org.hibernate.PropertyAccessException: Exception occurred inside getter of com.pending.model.Company.id [INFO] [talledLocalContainer]   at org.springframework.orm.hibernate5.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:267) [INFO] [talledLocalContainer]   at java.base/java.lang.Thread.run(Thread.java:833) [INFO] [talledLocalContainer] Caused by: org.hibernate.PropertyAccessException: Exception occurred inside getter of com.pending.model.Company.id [INFO] [talledLocalContainer]   at org.hibernate.property.access.spi.GetterMethodImpl.get(GetterMethodImpl.java:45) [INFO] [talledLocalContainer] Caused by: java.lang.reflect.InvocationTargetException [INFO] [talledLocalContainer]   at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [INFO] [talledLocalContainer]   ... 130 more [INFO] [talledLocalContainer] Caused by: java.lang.NullPointerException: Cannot invoke "java.lang.Integer.intValue()" because "this.id" is null [INFO] [talledLocalContainer]   at com.pending.model.Company.getId(Company.java:15) [INFO] [talledLocalContainer]   ... 135 more [INFO] [talledLocalContainer]

Is your Company class annotated with @Entity in your code?
Reference https://www.baeldung.com/jpa-entities

Himai Minh wrote:Is your Company class annotated with @Entity in your code?
Reference https://www.baeldung.com/jpa-entities

Nope. Annotations are not used here. I believe the code I'm working on belongs to the time when annotations weren't there. I've included my Company class above as well reference.

It started working. My table was not setup for autoincrement and hence I was getting errors.

There you go. Don't you hate it when you provide copious documentation and then the problem is somewhere else? Anyway, good to hear the problem is located and solved.

Paul Clapham wrote:There you go. Don't you hate it when you provide copious documentation and then the problem is somewhere else? Anyway, good to hear the problem is located and solved.

Yeah, not sure what happened now but it only seems to be working with save() method and not with saveOrUpdate(). With saveOrUpdate it is giving me same error as I got at the start.

[INFO] [talledLocalContainer] Caused by: java.lang.NullPointerException: Cannot invoke "java.lang.Integer.intValue()" because "this.id" is null [INFO] [talledLocalContainer]   at com.pending.model.Company.getId(Company.java:14)

Completely confused as why it is happening and same thing worked in the morning.

Hi, Jack,
Save is fine because the id can be auto generated. But update is not fine. That gives you a clue that the id is not found.
Do you provide the right id to look up in the DB first?

Himai Minh wrote:Hi, Jack,
Save is fine because the id can be auto generated. But update is not fine. That gives you a clue that the id is not found.
Do you provide the right id to look up in the DB first?

Hi Himai,
Thanks for your response. So I am only doing an insert so could you tel me why update is coming into picture here? Also, what id it is looking to find - I am not understanding this part. Since I'm just inserting the records, I am not providing any id since it's autogenerated in my SQL server table as I've set it as an Identity.

Pease let me know if I can answer any questions.

Hi, Jack,
To my understanding, your issue comes from saveOrUpdate(). I believe  you are trying to update a record while that record has not even existed yet.

Himai Minh wrote:Hi, Jack,
To my understanding, your issue comes from saveOrUpdate(). I believe  you are trying to update a record while that record has not even existed yet.

Hmm, that part is still confusing me as I'm just sending name and comment from the form, and in this case saveOrUpdate() should act as save(). So not sure why it is looking at an update.

If the name and comment are new data, then try to use save instead of saveOrUpdate.

Himai Minh wrote:If the name and comment are new data, then try to use save instead of saveOrUpdate.

Yeah, that's what I am doing right now until I figure this out. But I was hoping saveOrUpdate should hand handed that such that I won't have to use saveOrUpdate once I go for updating something.

But when you need to update a comment, you should first retrieve the comment ID and then update the comment.

Yes, Thanks Minh.

Good news is that I created a separate table and then new classes and mapping files and it works fine now with saveOrHibernate. Not sure why above code was creating issues but I didn't bother to spend more time on it as my new attempt worked.

Hi Jack,
So, what is your new approach?
Do you separate the save and update operations ?
For example, the save operation is for creating a new comment.
The update is for updating an existing comment.

Himai Minh wrote:Hi Jack,
So, what is your new approach?
Do you separate the save and update operations ?
For example, the save operation is for creating a new comment.
The update is for updating an existing comment.

I'm still using saveOrHibernate(). The only things that I changed are the new table with new column names. Based on that I modified the code.

Hi Jack,
I read this article https://www.digitalocean.com/community/tutorials/hibernate-session-merge-vs-update-save-saveorupdate-persist-example
I don't see saveOrHibernate() method.

Himai Minh wrote:Hi Jack,
I read this article https://www.digitalocean.com/community/tutorials/hibernate-session-merge-vs-update-save-saveorupdate-persist-example
I don't see saveOrHibernate() method.

Sorry, I meant saveOrUpdate() - just like I have shown in my code