I have been very impressed with Javers. Unfortunately, I am currently on a project that features poorly designed legacy code. I seek guidance in the application of JaversAuditable, JaversAuditableDelete, and JaversAuditableConditionalDelete annotations under the following scenarios:
Suppose my DAOs are using hibernate's update and merge methods. Should I adorn these DAO methods with any of the above annotations?
Suppose now that I have malformed DAO methods like the following:
public Group createNewGroup(String title, String desc, String color, int type) {
Group group = new Group();
group.setGroupTitle(title);
group.setGroupDesc(desc);
group.setGroupColor(color);
group.setType(type);
group.setCategory(Group.CATEGORY_GROUP);
getHibernateTemplate().save(group);
return group;
}
or
public void updateAlerts(Long userId) {
final String hqlUpdate = "update Alert a set a.acknowleged = true where a.systemUser.systemUserId = ?0";
try {
getHibernateTemplate().bulkUpdate(hqlUpdate, userId);
} catch(Exception e){
throw new RuntimeException(e);
}
}
are any of the annotations applicable to these methods?
I expect from examination of the JaversCommitAdvice class that the aforementioned annotations will not work. I would like to know what I can do short of manually calling Javers.commit() in each of these malformed DAO methods.
Related
I have a Spring Boot project which has multiple Model class
I want to use multiple model classes in my DAO implementation.
Can someone please explain how can I use HQL queries here.
Most of the examples i saw uses CRUDRepository. But in my understanding this limits us to one model class (please correct me if my understanding is wrong).
Secondly using CRUDRepository limits me to very specific methods. But HQL queries I need could be more complex like:
Query query = session.createQuery(from Employee where name=:name and place=:place and phone=:phone and gender=:gender);
Is it standard practice to use CRUDRepository even for HQL queries like this.
Otherwise how can I use such HQL queries. (If possible please also add what all dependencies and annotations i will need to add). I am using Hibernate and postgres.
If you wish to execute dynamic HQL queries without using repositories, etc, this works for me really nicely:
#Autowired
EntityManager entityManager;
#RequestMapping("/query")
#ResponseBody
public String testQuery() {
Query query = entityManager.createQuery("select u from User u");
List<User> users = query.getResultList();
users.forEach(u -> System.out.println(u.getFirstname()));
return "See Console";
}
The nice thing about it is that if you're quickly wanting to test a query, and you're using something like Spring LiveReload, JRebel, DCEVM or HotSwap with Hybris, you can change the query and save and refresh.
CRUD repositories are the standard way to write a DAO. If you look at the documentations, you will see that you can have complex queries that uses the fields of the entity (which can be pretty complex, I encourage you to look here at the query methods part - 4.3), and if you want even more complex methods, you can use the annotation #Query over a method:
#Repository
interface MyRepo implements JpaRepository<MyEntity,Long> {
#Query("your custom query here")
MyEntity findByFeature(String a)
}
Now you can insert you query and access you String a inside the query (like Select u where u.name="blabla" where blabla is your input string)
The #Query comes with the same dependency as the repositories (I think that spring-boot-starter-data-jpa is enough)
JpaRepository is surely awesome to use, but for someone who has to use complex HQL queries (due to your organization's recommendations etc), here is how i did it:
Get Session factory by injecting following bean in your configuration:
#Bean
public SessionFactory sessionFactory(#Qualifier("entityManagerFactory") EntityManagerFactory emf)
{
return emf.unwrap(SessionFactory.class);
}
Add EntityScan and ComponentScan to your configuration class
#EntityScan(basePackages = { "com.app.persistence" })
#ComponentScan(basePackages = { "com.app" })
Go ahead and use any HQL queries:
#Autowired
SessionFactory factory;
#Override
public String check() {
Session session = null;
try {
session = factory.openSession();
Query query = session.createQuery("from Test");
List<Test> res = query.list();
Test sing = res.get(0);
return sing.getName();
} catch (Exception e) {
System.out.println("Exception in Dao");
e.printStackTrace();
throw e;
} finally {
if (session != null) {
session.close();
}
}
}
Note: I am assuming that other things like configuring DataSource and all have been taken care already.
Anyone can feel free to correct me if my understanding or way was wrong.
But it worked well for me this way!! :)
My question is about what is best way to inhibit an endpoint that is automatically provided by Olingo?
I am playing with a simple app based on Spring boot and using Apache Olingo.On short, this is my servlet registration:
#Configuration
public class CxfServletUtil{
#Bean
public ServletRegistrationBean getODataServletRegistrationBean() {
ServletRegistrationBean odataServletRegistrationBean = new ServletRegistrationBean(new CXFNonSpringJaxrsServlet(), "/user.svc/*");
Map<String, String> initParameters = new HashMap<String, String>();
initParameters.put("javax.ws.rs.Application", "org.apache.olingo.odata2.core.rest.app.ODataApplication");
initParameters.put("org.apache.olingo.odata2.service.factory", "com.olingotest.core.CustomODataJPAServiceFactory");
odataServletRegistrationBean.setInitParameters(initParameters);
return odataServletRegistrationBean;
} ...
where my ODataJPAServiceFactory is
#Component
public class CustomODataJPAServiceFactory extends ODataJPAServiceFactory implements ApplicationContextAware {
private static ApplicationContext context;
private static final String PERSISTENCE_UNIT_NAME = "myPersistenceUnit";
private static final String ENTITY_MANAGER_FACTORY_ID = "entityManagerFactory";
#Override
public ODataJPAContext initializeODataJPAContext()
throws ODataJPARuntimeException {
ODataJPAContext oDataJPAContext = this.getODataJPAContext();
try {
EntityManagerFactory emf = (EntityManagerFactory) context.getBean(ENTITY_MANAGER_FACTORY_ID);
oDataJPAContext.setEntityManagerFactory(emf);
oDataJPAContext.setPersistenceUnitName(PERSISTENCE_UNIT_NAME);
return oDataJPAContext;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
...
My entity is quite simple ...
#Entity
public class User {
#Id
private String id;
#Basic
private String firstName;
#Basic
private String lastName;
....
Olingo is doing its job perfectly and it helps me with the generation of all the endpoints around CRUD operations for my entity.
My question is : how can I "inhibit" some of them? Let's say for example that I don't want to enable the delete my entity.
I could try to use a Filter - but this seems a bit harsh. Are there any other, better ways to solve my problem?
Thanks for the help.
As you have said, you could use a filter, but then you are really coupled with the URI schema used by Olingo. Also, things will become complicated when you have multiple, related entity sets (because you could navigate from one to the other, making the URIs more complex).
There are two things that you can do, depending on what you want to achieve:
If you want to have a fined grained control on what operations are allowed or not, you can create a wrapper for the ODataSingleProcesor and throw ODataExceptions where you want to disallow an operation. You can either always throw exceptions (i.e. completely disabling an operation type) or you can use the URI info parameters to obtain the target entity set and decide if you should throw an exception or call the standard single processor. I have used this approach to create a read-only OData service here (basically, I just created a ODAtaSingleProcessor which delegates some calls to the standard one + overridden a method in the service factory to wrap the standard single processor in my wrapper).
If you want to completely un-expose / ignore a given entity or some properties, then you can use a JPA-EDM mapping model end exclude the desired components. You can find an example of such a mapping here: github. The mapping model is just an XML file which maps the JPA entities / properties to EDM entity type / properties. In order for olingo to pick it up, you can pass the name of the file to the setJPAEdmMappingModel method of the ODataJPAContext in your initialize method.
In my application, I need to retrieve the lists of new, updated and removed entities per each transaction. Like this:
// useful functionality
#Transactional
public void createNewBlogPost(int userId, String title, String text) {
Post post = new Post();
post.title = title; // "hello"
post.text = text; // "there"
postRepository.save(post);
// more work with JPA repositories here
}
...
// gets called right after createNewBlogPost()
public void onTransaction(UnitOfWork uow) {
List<?> newEntities = uow.getNewEntities();
assertEquals(1, newEntities.size()); // 1 new entity
Object firstNewEntity = newEntities.get(0);
assertTrue(firstNewEntity instanceof Post); // this new entity
// is a Post
Post newPost = (Post)firstNewEntity;
assertEquals("hello", newPost.title);
assertEquals("there", newPost.text);
}
The most relevant thing I managed to find was an audit functionality that Spring provides with annotations like #CreatedBy, #CreatedDate, #LastModifiedBy, #LastModifiedDate. Though it's technically very close, yet it's not exactly what I want to achieve.
Does Spring Data JPA provide a mechanism to retrieve data changes per every single transaction?
Since your use case is Hibernate and JPA specific, you should take a look at Hibernate Envers and Spring Data Envers. They might give you some ideas, but be careful re: the projects themselves, I'm not sure if they're active.
I've spent some time for the research and managed to find a relatively straightforward Hibernate-specific solution. There are basically 2 problems to resolve:
Intercept data change events.
Do it on a per-request basis.
To address p.1, one can use EventListenerRegistry. Here's an example:
#Component
public class HibernateListenersConfigurer {
#Autowired
private EntityManagerFactory entityManagerFactory;
#Autowired
private HibernateListeners hibernateListeners;
#PostConstruct
public void init() {
HibernateEntityManagerFactory hibernateEntityManagerFactory =
(HibernateEntityManagerFactory)entityManagerFactory;
SessionFactoryImpl sessionFactoryImpl =
(SessionFactoryImpl)hibernateEntityManagerFactory.getSessionFactory();
EventListenerRegistry eventListenerRegistry = sessionFactoryImpl.
getServiceRegistry().
getService(EventListenerRegistry.class);
eventListenerRegistry.appendListeners(EventType.PRE_INSERT, hibernateListeners);
eventListenerRegistry.appendListeners(EventType.PRE_UPDATE, hibernateListeners);
eventListenerRegistry.appendListeners(EventType.PRE_DELETE, hibernateListeners);
}
}
hibernateListeners object gets all these events and can do whatever required to audit them. Here's an example:
#Component
public class HibernateListeners implements
PreInsertEventListener,
PreUpdateEventListener,
PreDeleteEventListener {
#Autowired
private ChangeTracker changeTracker;
#Override
public boolean onPreInsert(PreInsertEvent event) {
// event has a bunch of relevant details
changeTracker.trackChange(event);
return false;
}
...other listeners here...
Then, to address p.2, changeTracker seen above is a request-scoped bean:
#Component
#Scope(value = "request", proxyMode = ScopedProxyMode.TARGET_CLASS)
public class ChangeTracker {
// a sort of "Unit of Work"
private List<Change> changes = new ArrayList<Change>();
public void trackChange(PreInsertEvent event) {
changes.add(makeChangeFromEvent(event));
}
public void handleChanges() {
// Do whatever needed :-)
}
}
Then, there are few options available to finally call handleChanges() once request processing is complete: call it manually, use HandlerInterceptor, use filter, use AOP. HandlerInterceptors and filters, are not as great, because in my case they were getting called after response has already been sent to the client, this caused inconsistency between "business data" and "changes data". I eventually switched to AOP and it seems to work just fine.
Here's a playground: https://github.com/loki2302/spring-change-tracking-experiment
I am upgrading a working project from Spring2+Hibernate3 to Spring3+Hibernate4. Since HibernateTemplate and HibernateDAOSupport have been retired, I did the following
Before (simplified)
public List<Object> loadTable(final Class<?> cls)
{
Session s = getSession(); // was calling the old Spring getSession
Criteria c = s.createCriteria(cls);
List<Object> objects = c.list();
if (objects == null)
{
objects = new ArrayList<Object>();
}
closeSession(s);
return objects;
}
Now (simplified)
#Transactional(propagation=Propagation.REQUIRED)
public List<Object> loadTable(final Class<?> cls)
{
Session s = sessionFactory.getCurrentSession();
Criteria c = s.createCriteria(cls);
List<Object> objects = c.list();
if (objects == null)
{
objects = new ArrayList<Object>();
}
return objects;
}
I also added the transaction annotation declaration to Spring XML and removed this from Hibernate properties
"hibernate.current_session_context_class", "org.hibernate.context.ThreadLocalSessionContext"
The #Transactional annotation seems to have worked as I see this in the stacktrace
at com.database.spring.DatabaseDAOImpl$$EnhancerByCGLIB$$7d20ef95.loadTable(<generated>)
During initialization, the changes outlined above seem to work for a few calls to the loadTable function but when it gets around to loading an entity with a parent, I get the "collection with cascade="all-delete-orphan" was no longer referenced" error. Since I have not touched any other code that sets/gets parents or children and am only trying to fix the DAO method, and the query is only doing a sql SELECT, can anyone see why the code got broken?
The problem seems similar to Spring transaction management breaks hibernate cascade
This is unlikely problem of Spring, but rather issue with your entity handling / definition. When you are using deleteOrphans on a relation, the underlying PersistentSet MUST NOT be removed from the entity itself. You are allowed only to modify the set instance itself. So if you are trying to do anything clever within your entity setters, that is the cause.
Also as far as I remember there are some issues when you have deleteOrphans on both sides of the relation and/or load/manipulate both sides within one session.
Btw. I don't think "hibernate.current_session_context_class", "org.hibernate.context.ThreadLocalSessionContext" is necessary. In our project, this is the only configuration we have:
#Bean
public LocalSessionFactoryBuilder sessionFactoryBuilder() {
return ((LocalSessionFactoryBuilder) new LocalSessionFactoryBuilder(
dataSourceConfig.dataSource()).scanPackages(ENTITY_PACKAGES).
setProperty("hibernate.id.new_generator_mappings", "true").
setProperty("hibernate.dialect", dataSourceConfig.dialect()).
setProperty("javax.persistence.validation.mode", "none"));
}
#Bean
public SessionFactory sessionFactory() {
return sessionFactoryBuilder().buildSessionFactory();
}
The issue was with Session Management. The same block of transactional code was being called by other modules that were doing their own session handling. To add to our woes, some of the calling modules were Spring beans while others were written in direct Hibernate API style. This disorganization was sufficient work to keep us away from moving up to Hibernate 4 immediately.
Moral of the lesson (how do you like that English?): Use a consistent DAO implementation across the entire project and stick to a clearly defined session and transaction management strategy.
I have been going through some Spring / AOP tutorials and have somewhat familiarized myself with the related concepts.
Now coming to my requirements, I need to create an Activities Log implementation which will save the activities of a logged-in user in the DB which can range from applying for a service or creating new users in case of Admin users, etc. On invocation of any method having an annotation (say #ActivityLog), this information is to be persisted in the form of actorId, actionComment, actionTime, actedUponId, ... etc.
Now, if I create a POJO class (that maps to a ActivityLog table in the DB) and want to save this data from inside the Advice (preferably using the same transaction as the method, method uses #Transactional annotation), how do I actually populate the variables in this POJO?? I can probably get the actorId from the session object & actionTime can simply be new Date() but how about the dynamic values for actionComment / actedUponId?
Any help will be brilliant! (BTW, I have a requirement to not use Hibernate Interceptors.)
Here is a complete example:
#Aspect
#Component
public class WebMethodAuditor {
protected final Log logger = LogFactory.getLog(getClass());
public static final String DATE_FORMAT_NOW = "yyyy-MM-dd HH:mm:ss";
#Autowired
AuditRecordDAO auditRecordDAO;
#Before("execution(* com.mycontrollers.*.*(..))")
public void beforeWebMethodExecution(JoinPoint joinPoint) {
Object[] args = joinPoint.getArgs();
String methodName = joinPoint.getSignature().getName();
User principal = (User)SecurityContextHolder.getContext().getAuthentication().getPrincipal();
Timestamp timestamp = new Timestamp(new java.util.Date().getTime());
// only log those methods called by an end user
if(principal.getUsername() != null) {
for(Object o : args) {
Boolean doInspect = true;
if(o instanceof ServletRequestDataBinder) doInspect = false;
if(o instanceof ExtendedModelMap) doInspect = false;
if(doInspect) {
if(o instanceof BaseForm ) {
// only show form objects
AuditRecord ar = new AuditRecord();
ar.setUsername(principal.getUsername());
ar.setClazz(o.getClass().getCanonicalName());
ar.setMethod(methodName);
ar.setAsString(o.toString());
ar.setAudit_timestamp(timestamp);
auditRecordDAO.save(ar);
}
}
}
}
}
}
If you are looking to get the actionComment and actedUponId from arguments to the annotated method (assuming they're both strings), you can add binding terms to your #Around pointcut like this:
#Around("#annotation(ActivityLog) && args(actionComment,actedUponId)")
public Object logActivity(ProceedingJoinPoint pjp,
String actionComment, String actedUponId) throws Throwable {
// ... get other values from context, etc. ...
// ... write to log ...
pjp.proceed();
}
The args binding in a pointcut can be used in partially-specified mode, in case there are other arguments about that you aren't interested in, and since the aspect is itself a bean, it can be wired into everything else that is going on in the normal way.
Note that if you're mixing declarative transaction management on the same method calls, you've got to get the order of aspects correct. That's done in part by making the aspect bean also implement the Spring Ordered interface, and by controlling the precedence of transactions through the order attribute to <tx:annotation-driven/>. (If that's impossible, you'll be forced to do clever things with direct transaction handling; that's a vastly more painful option to get right…)
You will be getting a reference to the org.aspectj.lang.JoinPoint in your advice.You can get the name of target method being executed with toShortString().You can have a loop-up/property file with the method-name=comments entries.This comments can be populated into the POJO.actionComment.method-name can be set to POJO.actedUponId.
I hope the advice should run within the same transaction, if the data-access method is adviced and the service method uses #Transactional.