Twitter bootstrap - updating value in junction table is troublesome spring data JPA

ArshadAli
October 14, 2015
256 views
0 votes
2 Answers

I have two Entities one as

@Entity    
public class Job {  

    @Id
    @GeneratedValue
    private Integer id;

    @Size(min = 5,max = 50, message = "Valid title is 5-50 chars")
    private String title;       

    @ManyToMany(cascade = {CascadeType.MERGE})
    @JoinTable(name = "jobs_categories",
                joinColumns = @JoinColumn(name = "jobs_id"),
                inverseJoinColumns = @JoinColumn(name = "categories_id"))
    private List<Category> categories;
    // omitting setters/getters
}

and other as

@Entity
public class Category {    

    @Id
    @GeneratedValue
    private Integer id;

    @Size(min = 5,max = 15, message = "Valid name is 5-15 chars")
    private String name;

    @ManyToMany(mappedBy = "categories", cascade = {CascadeType.MERGE}) 
    private List<Job> jobs; 
    // omitting setters/getters
    }

I want to implement CRUD operations on those two,
I save one job with some categories as

Job title - Fullstack JavaScript CSS3 / HTML5 / Developer
Categories - AngularJS, Backbone.js, CSS, CSS3, Graphic design, HTML, HTML5,
             JavaScript, MongoDB Node.js, twitter bootstrap, Web design.

then if I want to update the job by adding or removing categories from above saved Job, it is never updating (e.g, adding/removing) categories.

for updating Job I have method in JobService as

@Service
public class JobService{

    @Autowired
    private JobRepository jobRepository;

    @Autowired
    private CategoryRepository categoryRepository;

    @Autowired
    private LocalContainerEntityManagerFactoryBean entityManagerFactory;

    private Session session;

    Logger logger = LoggerFactory.getLogger(JobService.class);      

    public void updateJobCategory(Job job) {                
    EntityManager entityManager = entityManagerFactory.getObject().createEntityManager();
    session= entityManager.unwrap(org.hibernate.Session.class);
    logger.info("got Job ID as  ==> " + String.valueOf(job.getId()));
    Job jobObj = (Job) session.get(Job.class, job.getId());
    jobObj.getCategories().clear();     
    logger.info("got Job ID as  ==> " + String.valueOf(jobObj.getId()));

    if (!job.getCategories().isEmpty()) {
        logger.info("got job.getCategories() as not Null");
        List<Category> categories = job.getCategories();
        for (Category category : categories) {              
            logger.info("Good job.getCategories() to update ==> " + category.getName());
        }
        logger.info("adding job.getCategories() to update ==> ");
        jobObj.setCategories(job.getCategories());      

    }else {
        logger.info("got job.getCategories() as Null");
    }
    session.update(jobObj); 

    }
    public void update(Job job) {
        jobRepository.update(job.getId(), job.getTitle());
        updateJobCategory(job);
    }
}

I get log

logger.info("Got job.getCategories() to update" + category.getName());

I’m getting updated (new added/old removed) list of all categories,

Hibernate: update job set title=? where id=?
INFO : com.rhcloud.jobsnetwork.service.JobService - got Job ID as  ==> 1
Hibernate: select job0_.id as id1_1_0_, job0_.title as title7_1_0_ from job job0_ where job0_.id=?
Hibernate: select categories0_.jobs_id as jobs_id1_1_0_, categories0_.categories_id as categori2_2_0_, category1_.id as id1_0_1_, category1_.name as name2_0_1_ from jobs_categories categories0_ inner join category category1_ on categories0_.categories_id=category1_.id where categories0_.jobs_id=?
INFO : com.rhcloud.jobsnetwork.service.JobService - got Job ID as  ==> 1
INFO : com.rhcloud.jobsnetwork.service.JobService - got job.getCategories() as not Null
INFO : com.rhcloud.jobsnetwork.service.JobService - Good job.getCategories() to update ==> iOS App Dev
INFO : com.rhcloud.jobsnetwork.service.JobService - Good job.getCategories() to update ==> Android App Dev
INFO : com.rhcloud.jobsnetwork.service.JobService - adding job.getCategories() to update

but when I see details of Job I get the categories listed which were added on the creation of job not updated ones, I guess it is not updating categories id values in junction table jobs_categories.
No idea of Updating categories related to job?

UPDATE

When I use

public void persistJob(Job newJob) {
         em.persist(newJob);
       }

       public void saveJob(Job job) {
          em.merge(job);
       }
       public void persistCategory(Category newcat) {
         em.persist(newcat);
       }

without @Transactional at every method I get expception

javax.persistence.TransactionRequiredException: No transactional EntityManager available
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:275)
    at com.sun.proxy.$Proxy167.persist(Unknown Source)
    at com.rhcloud.jobsnetwork.service.JobService.persistJob(JobService.java:29)
    at com.rhcloud.jobsnetwork.service.JobService$$FastClassBySpringCGLIB$$53974ce3.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:649)
    at com.rhcloud.jobsnetwork.service.JobService$$EnhancerBySpringCGLIB$$c08e8d16.persistJob(<generated>)
    at com.rhcloud.jobsnetwork.controllers.JobController.addJobDetail(JobController.java:86)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

After adding @Transactional it works got rid of above exception, I save new job using

@RequestMapping(value = "/add-job", method = RequestMethod.POST)
    public String addJobDetail(@ModelAttribute("job") Job job) {            
        jobService.persistJob(job); 
        return "redirect:/";
    }

I get all the things working perfect, but when I use saveJob in JobController as

@RequestMapping(value = "/updated", method = RequestMethod.POST)
    public String updateJob(@ModelAttribute("job") Job job) {           
        jobService.saveJob(job);
        return "redirect:/";
    }

there is no any category(no earlier added no updated ones) saved in updated job, any suggestions in this case.

Update – 2

As per your suggestion I added logger to

 @Transactional
   public void saveJob(Job job) {
       logger.error("got job.getCategories() of " + job.getCategories().size());
      em.merge(job);         
   }

at this point I get NullPointerException at

 logger.error("got job.getCategories() of " + job.getCategories().size() + " size");

log/trace is

java.lang.NullPointerException
    at com.rhcloud.jobsnetwork.service.JobService.saveJob(JobService.java:37)
    at com.rhcloud.jobsnetwork.service.JobService$$FastClassBySpringCGLIB$$53974ce3.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
    at com.rhcloud.jobsnetwork.service.JobService$$EnhancerBySpringCGLIB$$41dc2ac2.saveJob(<generated>)
    at com.rhcloud.jobsnetwork.controllers.JobController.updateJob(JobController.java:109)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:745)

Answers

You have wrong mapping.
Try this:

@Entity
public class Category {    

@Id
@GeneratedValue
private Integer id;

@Size(min = 5,max = 15, message = "Valid name is 5-15 chars")
private String name;

@ManyToMany(cascade = CascadeType.ALL,orphanRemoval = true) 
@JoinColumn(name = "jobs_id",referencedColumnName = "jobs_id")
private List<Job> jobs; 
// omitting setters/getters
}

and second entity:

@Entity    
public class Job {  

@Id
@GeneratedValue
private Integer id;

@Size(min = 5,max = 50, message = "Valid title is 5-50 chars")
private String title;       

@ManyToMany(cascade = CascadeType.ALL,orphanRemoval = true)
@JoinColumn(name = "categories_id",referencedColumnName = "categories_id")
private List<Category> categories;
// omitting setters/getters
}

P.s. edit column names as in table;

In your case, you have two entities, that can each exist on their own – category is fine without a job, and a job can have no categories assigned. orphanRemoval is used in OnetoMany or OneToOne, if you would like to perform a delete operation on the related entity that is no longer referenced from the parent entity(think composition), which isn’t the case here. I believe you merely want to remove the link between the job and a the particular Category(think association).

You mapping is correct (bidirectional manytomany with Job as the relationship owner), I would suggest only minor modifications:
Use java.util.Set(improve performance with delete on join table, prevent ‘can not fetch multiple bags’ exception) for you collections and override equals method(to make collection operations easier).

Here we go:

@Entity    
public class Job { 
@Id
@GeneratedValue
private Integer id;

private String title;

@ManyToMany(fetch=FetchType.EAGER,cascade = { CascadeType.MERGE })
@JoinTable(name = "jobs_categories", joinColumns = @JoinColumn(name = "jobs_id") , inverseJoinColumns = @JoinColumn(name = "categories_id") )
private Set<Category> categories = new HashSet<Category>();

And Category

@Entity
public class Category {

@Id
@GeneratedValue
private Integer id;

private String name;

@ManyToMany(mappedBy = "categories", cascade = { CascadeType.MERGE })
private List<Job> jobs;

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Category other = (Category) obj;
    if (id == null) {
        if (other.id != null)
            return false;
    } else if (!id.equals(other.id))
        return false;
    return true;
}

One of the issues in your update function is that you override a reference to the collection in the Job entity.

jobObj.setCategories(job.getCategories());

You should always modify the original collection, never assign a new collection.

You might also consider removing the Merge cascade altogether from your ManyToMany as it will make the code workflow easier to understand – categories will be managed separately and you only add already saved categories to the new Job instance(but this is just a suggestion, we will make it work even with the cascade 🙂 ).

Now for some test code. I am using plain JPA, not Spring repositories, to make it simple to understand.

JobService(in your case it will be split into multiple classes, repositories..):

public class JobService {

   @PersistenceContext
   EntityManager em;

   public void persistJob(Job newJob) {
     em.persist(newJob);
   }

   public Job getJob(Integer jobId) {
     return em.find(Job.class, jobId);
   }

   public void saveJob(Job job) {
      em.merge(job);
   }

   public void persistCategory(Category newcat) {
     em.persist(newcat);
   }

   public List<Category> getAllCategories() {
     return em.createQuery("from Category", Category.class).getResultList();
   }  
}

And lets test it:

Job job = new Job();
job.setTitle("Web developer");
Category catJS = new Category();
catJS.setName("javascript");
Category catCSS = new Category();
catCSS.setName("CSS");
Category catNG = new Category();
catNG.setName("AngualrJS");
Category catHTML = new Category();
catHTML.setName("HTML5");
//persist categories separately
jobservice.persistCategory(catNG);
jobservice.persistCategory(catCSS);
jobservice.persistCategory(catHTML);
jobservice.persistCategory(catJS);
//at this point, we have 4 categories as managed entities
//add the saved categories to a new job instance
job.getCategories().add(catHTML);
job.getCategories().add(catJS);

//save job in DB
jobservice.persistJob(job);
//we do not need to set Job references in Category objects, because Job is the relationship owner - it will correctly update the FKs in join table
assertNotNull("job should be saved", job.getId());
Job fromDb = jobservice.getJob(job.getId());//reload from DB
assertNotNull("job should be stored in DB", fromDb);
assertTrue("job should have 2 categories", fromDb.getCategories().size() == 2);
//great si far so good  

//remove one of the assigned categories from Job(this is where you need that **equals** method in Category )
fromDb.getCategories().remove(catHTML);
assertTrue("job should not have only one category in Memory", fromDb.getCategories().size() ==1);
jobservice.saveJob(fromDb);
//we do not want to delete the *HTML* category from DB, just remove it from the particular job
Job fromDbAfterUpdate = jobservice.getJob(job.getId());
assertTrue("job should not have only one category in BD", fromDbAfterUpdate.getCategories().size() ==1);
List<Category> allCategories = jobservice.getAllCategories();
assertTrue("there should still be 4 categories in DB", allCategories.size() == 4);


//now lets test the Merge cascade
Category unsavedCategory = new Category();
unsavedCategory.setName("jquery");
fromDbAfterUpdate.getCategories().add(unsavedCategory );
//we have added an unsaved category to an  existing job. As Job has cascade merge on it categories, the *unsavedCategory* will be saved and then linked to job via job_category join table
jobservice.saveJob(fromDbAfterUpdate);
fromDbAfterUpdate = jobservice.getJob(fromDbAfterUpdate.getId());
assertTrue("job should now have 2 categories", fromDbAfterUpdate.getCategories().size() ==2);


// one more test, add and remove at the same time
fromDbAfterUpdate.getCategories().remove(catJS);
fromDbAfterUpdate.getCategories().add(catHTML);
fromDbAfterUpdate.getCategories().add(catCSS);
jobservice.saveJob(fromDbAfterUpdate);
fromDbAfterUpdate = jobservice.getJob(fromDbAfterUpdate.getId());
assertTrue("job should now have 3 categories", fromDbAfterUpdate.getCategories().size() ==3);
allCategories = jobservice.getAllCategories();
assertTrue("there should be 5 categories in DB", allCategories.size() == 5);

TL;DR

Keep your update method simple – you do not need to fetch the object from DB and move things between managed and detached object, let JPA merge do its thing
Never change a reference to a collection of managed entities – perform operations directly on the collection
Omit any cascades until you really need them

For more info, please consult JPA Spec

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Twitter bootstrap – updating value in junction table is troublesome spring data JPA

Update – 2

Answers