I use Stripes framework with Stripersist.
I want my webapp to use two different databases : in my persistence.xml, I want two different persistence-unit.
How can I do that ? Is it possible ?
Finally we removed Stripersist and build our own stack. We don't try the solution proposed by Kdeveloper.
First we wrote a Stripe interceptor :
#Intercepts({LifecycleStage.RequestInit, LifecycleStage.RequestComplete})
public class HibernateTxInterceptor implements net.sourceforge.stripes.controller.Interceptor {
private SessionFactory getUserSessionFactory(ExecutionContext context) {
return (SessionFactory) context.getActionBeanContext().getServletContext().getAttribute(MyInitListener.CTX_SESSION_USERS);
}
private SessionFactory getDocumentSessionFactory(ExecutionContext context) {
return (SessionFactory) context.getActionBeanContext().getServletContext().getAttribute(MyInitListener.CTX_SESSION_DOCUMENTS);
}
public Resolution intercept(ExecutionContext context) throws Exception {
LifecycleStage stage = context.getLifecycleStage();
if (stage == LifecycleStage.RequestInit) {
// Init transactions
Transaction userTx = getUserSessionFactory(context).getCurrentSession().beginTransaction();
Transaction documentTx = getDocumentSessionFactory(context).getCurrentSession().beginTransaction();
} else if (stage.equals(LifecycleStage.RequestComplete)) {
// Commit Transactions
Transaction userTx = getUserSessionFactory(context).getCurrentSession().getTransaction();
userTx.commit();
...
// Idem for documentTx...
}
}
And we created a servlet listener to inject the two Hibernate session factories using Spring :
public class Reef4iInitListener implements ServletContextListener {
public static final String CTX_SESSION_USERS = "user";
public static final String CTX_SESSION_DOCUMENTS = "document";
private ServletContext servletContext;
public void contextInitialized(ServletContextEvent e) {
servletContext = e.getServletContext();
final WebApplicationContext springContext = WebApplicationContextUtils.getWebApplicationContext(e.getServletContext());
SessionFactory usersSessionFactory = (SessionFactory) springContext.getBean("usersSessionFactory");
... // do the same with for document factory
}
public void contextDestroyed(ServletContextEvent e) {
SessionFactory userTx = (SessionFactory) e.getServletContext().getAttribute(CTX_SESSION_USERS);
userTx.close();
.... // do the same for document factory
}
You can use multiple peristence units with Stripersist. Although you can no longer use the getEntityManager() method:
Stripersist.getEntityManager()
You need to use one of these:
Stripersist.getEntityManager("Your PU name")
Or:
Stripersist.getEntityManager(YourEntity.class)
Related
I am running a Spring Boot application with a PostConstruct method to populate a POJO before application initialization. This is to ensure that the database isn't hit by multiple requests to get the POJO content after it starts running.
I'm able to pull the data from Oracle database through Hibernate query and store it in my POJO. The problem arises when I try to access the stored data. The dataset contains a list of objects that contain strings and numbers. Just trying to print the description of the object at the top of the list raises a class cast exception. How should I mitigate this issue?
#Autowired
private TaskDescrBean taskBean;
#PostConstruct
public void loadDescriptions() {
TaskDataLoader taskData = new TaskDataLoader(taskBean.acquireDataSourceParams());
List<TaskDescription> taskList = tdf.getTaskDescription();
taskBean.setTaskDescriptionList(taskList);
System.out.println("Task description size: " + taskBean.getTaskDescriptionList().get(0).getTaskDescription());
}
My POJO class:
#Component
public class TaskDescrBean implements ApplicationContextAware {
#Resource
private Environment environment;
protected List<TaskDescription> taskDescriptionList;
public Properties acquireDataSourceParams() {
Properties dataSource = new Properties();
dataSource.setProperty("hibernate.connection.driver_class", environment.getProperty("spring.datasource.driver-class-name"));
dataSource.setProperty("hibernate.connection.url", environment.getProperty("spring.datasource.url"));
dataSource.setProperty("hibernate.connection.username", environment.getProperty("spring.datasource.username"));
dataSource.setProperty("hibernate.connection.password", environment.getProperty("spring.datasource.password"));
return dataSource;
}
public List<TaskDescription> getTaskDescriptionList() {
return taskDescriptionList;
}
public void setTaskDescriptionList(List<TaskDescription> taskDescriptionList) {
this.taskDescriptionList = taskDescriptionList;
}
public ApplicationContext getApplicationContext() {
return applicationContext;
}
public void setApplicationContext(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
}
My DAO class:
public class TaskDataLoader {
private Session session;
private SessionFactory sessionFactory;
public TaskDataLoader(Properties connectionProperties) {
Configuration config = new Configuration().setProperties(connectionProperties);
config.addAnnotatedClass(TaskDescription.class);
sessionFactory = config.buildSessionFactory();
}
#SuppressWarnings("unchecked")
public List<TaskDescription> getTaskDescription() {
List<TaskDescription> taskList = null;
session = sessionFactory.openSession();
try {
String description = "from TaskDescription des";
Query taskDescriptionQuery = session.createQuery(description);
taskList = taskDescriptionQuery.list();
System.out.println("Task description fetched. " + taskList.getClass());
} catch (Exception e) {
e.printStackTrace();
} finally {
session.close();
}
return taskList;
}
TaskDescription Entity:
#Entity
#Table(name="TASK_DESCRIPTION")
#JsonIgnoreProperties
public class TaskDescription implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#Column(name="TASK_DESCRIPTION_ID")
private Long taskDescriptionId;
#Column(name="TASK_DESCRIPTION")
private String taskDescription;
public Long getTaskDescriptionId() {
return taskDescriptionId;
}
public void setTaskDescriptionId(Long taskDescriptionId) {
this.taskDescriptionId = taskDescriptionId;
}
public String getTaskDescription() {
return taskDescription;
}
public void setTaskDescription(String taskDescription) {
this.taskDescription = taskDescription;
}
}
StackTrace
Instead of sending the List in the return statement, I transformed it into a JSON object and sent its String representation which I mapped back to the Object after transforming it using mapper.readValue()
I have a HsqldbReconciler (for "work" with a HSQLDB database) which I autowired, like:
#Autowired
HsqldbReconciler hsqldbReconciler;
In Future there will be a OracleReconciler, MssqlReconciler, etc. I will need to use them accordingly to the type of connection a user has chosen.
How should I implement this? Usually I would have a kind of factory, which returns only the needed Reconciler. The only way in spring, I can currently imagine, is to Autowire an instance of each Reconciler, then use one of them in the code. Is there a better way?
make a Factory Class that will contain all your beans, e.g
#Component
class Factory{
#Autowired HsqldbReconciler hsqldb;
#Autowired OracleReconciler oracle;
#Autowired MssqlReconciler mssql;
public Object getInstance(String type){
switch(type){
case "mssql" : return mssql;
case "oracle" : return oracle;
// and so on
default : return null;
}
}
}
Now use this Factory as follows
class SomeClass{
#Autowired private Factory factory;
public Object someMethod(){
Object reconciler = factory.getInstance("mssql");
((MssqlReconciler)reconciler).someMethod();
}
}
Define them in your Config with the same name, but different conditions:
#Bean(name = "dbReconciler")
#Conditional(HsqldbReconcilerEnabled.class)
public ReconcilerBase getHsqldbReconciler() {
return new HsqldbReconciler();
}
#Bean(name = "dbReconciler")
#Conditional(OracleReconcilerEnabled.class)
public ReconcilerBase getOracleReconciler() {
return new OracleReconciler();
}
#Bean(name = "dbReconciler")
#Conditional(MssqlReconcilerEnabled.class)
public ReconcilerBase getMssqlReconciler() {
return new MssqlReconciler();
}
create conditions reading from app.properties:
HsqldbReconciler.enabled=true
OracleReconciler.enabled=false
MssqlReconciler.enabled=false
like this:
public class HsqldbReconcilerEnabled implements Condition {
private static final String PROP_ENABLED = "HsqldbReconciler.enabled";
#Override
public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
String property = context.getEnvironment().getProperty(PROP_ENABLED);
return Boolean.parseBoolean(property);
}
}
// etc...
use like:
#Autowired
#Qualifier("dbReconciler")
ReconcilerBase dbReconsiler;
ensure you're not enabling multiple beans at the same time.
I need to create an unmodifiable map generated from data obtained by querying a database. How, or can I, or is there a better way to do this using spring annotations?
I ran into a problem when creating a singleton for my Regions class and then trying to #Autowire in a RegionService to grab the object from the DAO. The problem is that spring can't instantiate the RegionService because it needs to instantiate the static singleton class Regions which needs to get data from the database as shown below in the constructor.
Please see me classes below (I've removed multiple unneeded methods that don't pertain to this question):
public final class Region {
private static final String DEFAULT_SEPERATOR = "-";
private final Integer key;
private final String description;
public Region(Integer pKey, String pDescription) {
this.key = pKey;
this.description = pDescription;
}
public Integer getKey() {
return this.key;
}
public String getValue() {
return this.description;
}
}
Here is my singleton:
public final class Regions {
private static Regions regionsInstance = null;
#Autowired
private RegionService regionService;
static Map<Integer, Region> regions;
private Regions() {
final Map<Integer, Region> tempRegions = new HashMap<Integer, Region>();
for (final Region region : this.regionService.retrieveAll()) {
tempRegions.put(region.getKey(), region);
}
regions = Collections.unmodifiableMap(tempRegions);
}
public static synchronized Regions getRegionsInstance() {
if (regionsInstance == null) {
regionsInstance = new Regions();
}
return regionsInstance;
}
public Region getRegion(final Integer pKey) {
return regions.get(pKey);
}
public List<Region> getRegions() {
return (List<Region>) regions.values();
}
}
My DAO and Service are just interfaces, no need to post those, here are my Impls:
#Service
public class RegionServiceImpl implements RegionService {
#Autowired
private RegionDAO regionDao;
#Override
public List<Region> retrieveAll() {
return this.regionDao.retrieveAll();
}
}
My DAOImpl (tested and works, just posting to give you the full picture):
#Repository
public class RegionDAOImpl implements RegionDAO {
private static final String SQL_RETRIEVE_REGIONS = "some random SQL";
#Autowired
private JdbcTemplate jdbcTemplate;
#Override
public List<Region> retrieveAll() {
try {
return this.jdbcTemplate.query(SQL_RETRIEVE_REGIONS, new ResultSetExtractor<List<Region>>() {
#Override
public List<Region> extractData(ResultSet rs) throws SQLException, DataAccessException {
return RegionDAOImpl.this.mapRegionData(rs);
}
});
} catch (final DataAccessException dae) {
throw new DaoException("Could not retrieve regionList from database. " + dae);
}
}
protected final List<Region> mapRegionData(ResultSet rs) throws SQLException {
final List<Region> regionList = new ArrayList<Region>();
while (rs.next()) {
regionList.add(new Region(rs.getInt("REGION_CD"), rs.getString("REGION_TXT")));
}
return Collections.unmodifiableList(regionList);
}
}
Then I run my test(I took out unneeded crap):
#..annotated with things you don't need to know
public class RetrieveRegionsTest {
#Autowired
private Regions r;
#Test
public void getAndLogRegion() {
final List<Region> regionDescriptions = new ArrayList<Region>(this.r.getRegions());
for (final Region region : regionDescriptions) {
LOGGER.info(region.getValue());
}
}
Yes my configuration and classpaths are set up properly. I can get this to work other ways, just not by accessing the Regions singleton which is what I want. Now I know I could take off the #Autowired on the RegionService in my Regions singleton and just create a new instance of RegionService, but that would defeat the purpose of springs #Autowired feature.
Any thoughts, ideas, comments?
The Service class and my repository classes in my spring MVC set up are something like this -
public class ObjectServiceImpl implements ObjectService {
#Autowired
Temp1Repo temp1Repo;
#Autowired
Temp2Repo temp2Repo;
...
}
public interface Temp1Repo extends CrudRepository<Temp1, Integer> {
}
public interface Temp2Repo extends CrudRepository<Temp2, Integer> {
}
Now, in my service class, i am getting a object of a type Temp1, I have to call temp1Repo.save(). If I get an object of Temp2, I have to call temp2Repo.save() and so on...
How do i achieve this?
Seems fairly simple to just have an if statement:
if(object instanceof Temp1) {
temp1Repo.save((Temp1) object);
} else if(object instanceof Temp2) {
temp2Repo.save((Temp2) object);
}
Or perhaps you are looking for a more generic way?
I suppose that you want to regroup all repositories in one. Something like
#SuppressWarnings("rawtypes")
public class ObjectServiceImpl {
#Autowired
private CrudRepository[] repositories;
private Map<Class<?>, CrudRepository> repositoryMap = new HashMap<Class<?>, CrudRepository>();
#PostConstruct
public void init() {
for (CrudRepository r : repositories)
repositoryMap.put(getType(r), r);
}
private Class<?> getType(CrudRepository repository) {
Type[] types = repository.getClass().getGenericInterfaces();
for (Type t : types) {
if (t instanceof ParameterizedType)
return (Class<?>) ((ParameterizedType) t).getActualTypeArguments()[0];
}
throw new IllegalStateException("Check repositories...");
}
public void save(Object entity) {
repositoryMap.get(entity.getClass()).save(entity);
}
public <T> T get(Object id, Class<T> clazz) {
return repositoryMap.get(clazz).findOne(id);
}
....
}
Consider to use EntityManager directly, but could be useful anyway...
Following the code you wrote, Spring will rise an exception at startup time if any injection is missing.
What you want to do is a dynamic Module load, depending on a condition you omitted within your question.
You probably have to use XML configuration style and create a by condition spring context and load the correct one to be used.
Cheers
I am using declarative transactions in Spring. I have a service layer which is annotated with "Transactional". This service layer calls the DAO. I need to enable a hibernate filter in all the dao methods. I don't want to have to explicitly call teh session.enablefilter each time. So is there a way using spring transaction aop etc such that a intercepter can be called when the hibernate session is created?
My Service layer:
#Service("customerViewService")
#Transactional
public class CustomerViewServiceImpl extends UFActiveSession implements CustomerViewService {
private static final Logger log = LoggerFactory.getLogger(CustomerViewServiceImpl.class);
private CustomerDAO daoInstance = null;
private CustomerDAO getCustomerDAO() {
if (daoInstance == null)
daoInstance = DAOFactory.getDao(CustomerDAO.class);
return daoInstance;
}
#Transactional(propagation=Propagation.REQUIRED, rollbackFor=DAOException.class)
public CustomerModel getCustomerModel() throws UFClientException {
CustomerModel model = null;
try {
Customer customerTbl = getCustomerDAO().getCustomerDetail(getUserName());
if (customerTbl == null) {
log.error("DAO-02: No entry found for Customer id- " + getUserName());
throw new UFClientException("DAO-02");
}
model = DozerConverter.hibernateToDto(customerTbl, CustomerModel.class);
}
catch (DAOException e) {
log.error("DAO-01: Not able to fetch entry from database for customer.");
throw new UFClientException();
}
return model;
}
}
My Dao Layer
public class CustomerDAOImpl extends HibernateDaoSupport implements CustomerDAO {
#SuppressWarnings("unchecked")
public Customer getCustomerDetail(String email) throws DAOException {
try {
List<Customer> customers = getHibernateTemplate().find(sb.toString(), email);
if (customers.size() == 0)
return null;
return customers.get(0);
}
catch (Exception e) {
throw new DAOException(e);
}
}
Appreciate your help!!
You can create your own interceptor, and apply it to methods that havbe transactional:
#AroundInvoke("#annotation(transactional)")
public ... handle(Transactional transactional) {
...
}