package com.discursive.dao.generic.hibernate;
import java.io.Serializable;
import java.lang.reflect.Method;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import org.apache.commons.lang.NotImplementedException;
import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.Query;
import org.hibernate.ScrollableResults;
import org.hibernate.Session;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Example;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
import com.discursive.dao.generic.GenericDao;
import com.discursive.dao.generic.spring.FinderIntroductionInterceptor;
@SuppressWarnings("unchecked")
public class GenericHibernate<T, ID extends Serializable> extends HibernateDaoSupport implements GenericDao<T, ID>,
FinderExecutor {
@SuppressWarnings("unchecked")
private Class persistentClass;
@SuppressWarnings("unchecked")
public GenericHibernate(Class persistentClass) {
this.persistentClass = persistentClass;
}
@SuppressWarnings("unchecked")
public T byId(ID id) {
return byId(id, false);
}
@SuppressWarnings("unchecked")
public T byId(ID id, boolean lock) {
T entity;
if (lock) {
entity = (T) getHibernateTemplate().get(getPersistentClass(), id, org.hibernate.LockMode.UPGRADE);
} else {
entity = (T) getHibernateTemplate().get(getPersistentClass(), id);
}
if( entity != null ) {
getHibernateTemplate().refresh(entity);
}
return entity;
}
@SuppressWarnings("unchecked")
public List<T> all() {
return getHibernateTemplate().loadAll(getPersistentClass());
}
@SuppressWarnings("unchecked")
public List<T> byExample(T exampleInstance, String... excludeProperty) {
HibernateCallback callback = generateExampleCallback(exampleInstance, excludeProperty);
return (List) getHibernateTemplate().execute(callback);
}
HibernateCallback generateExampleCallback(final T exampleInstance, final String... excludeProperty) {
HibernateCallback callback = new HibernateCallback() {
public Object doInHibernate(Session session) throws HibernateException, SQLException {
// Using Hibernate, more difficult with EntityManager and EJB-QL
Criteria crit = session.createCriteria(getPersistentClass());
Example example = Example.create(exampleInstance);
for (String exclude : excludeProperty) {
example.excludeProperty(exclude);
}
crit.add(example);
return crit.list();
}
};
return callback;
}
@SuppressWarnings("unchecked")
public T oneByExample(T exampleInstance, String... excludeProperty) {
HibernateCallback callback = generateOneByExampleCallback(exampleInstance, excludeProperty);
return (T) getHibernateTemplate().execute(callback);
}
HibernateCallback generateOneByExampleCallback(final T exampleInstance, final String... excludeProperty) {
HibernateCallback callback = new HibernateCallback() {
public Object doInHibernate(Session session) throws HibernateException, SQLException {
// Using Hibernate, more difficult with EntityManager and EJB-QL
Criteria crit = session.createCriteria(getPersistentClass());
Example example = Example.create(exampleInstance);
for (String exclude : excludeProperty) {
example.excludeProperty(exclude);
}
crit.add(example);
return crit.uniqueResult();
}
};
return callback;
}
@SuppressWarnings("unchecked")
public T makePersistent(T entity) {
return (T) getHibernateTemplate().merge(entity);
}
public T makeTransient(T entity) {
getHibernateTemplate().delete(entity);
return entity;
}
public Collection<T> makeTransient(Collection<T> entities) {
getHibernateTemplate().deleteAll(entities);
return entities;
}
public Class getPersistentClass() {
return persistentClass;
}
/**
* Use this inside subclasses as a convenience method.
*/
@SuppressWarnings("unchecked")
List<T> findByCriteria(final Criterion... criterion) {
HibernateCallback callback = generateCriteriaCallback(criterion);
return (List) getHibernateTemplate().execute(callback);
}
HibernateCallback generateCriteriaCallback(final Criterion... criterion) {
HibernateCallback callback = new HibernateCallback() {
public Object doInHibernate(Session session) throws HibernateException, SQLException {
Criteria crit = session.createCriteria(getPersistentClass());
for (Criterion c : criterion) {
crit.add(c);
}
return crit.list();
}
};
return callback;
}
/**
* Use this inside subclasses as a convenience method.
*/
@SuppressWarnings("unchecked")
protected T findUniqueByCriteria(final Criterion... criterion) {
HibernateCallback callback = new HibernateCallback() {
public T doInHibernate(Session session) throws HibernateException, SQLException {
Criteria crit = session.createCriteria(getPersistentClass());
for (Criterion c : criterion) {
crit.add(c);
}
return (T) crit.uniqueResult();
}
};
return (T) getHibernateTemplate().execute(callback);
}
@SuppressWarnings("unchecked")
public List<T> executeFinder(Method method, final Object[] queryArgs, LockMode lockMode) {
final String queryName = queryNameFromMethod(method);
final Query namedQuery = getQuery(queryName);
for (int i = 0; i < queryArgs.length; i++) {
Object arg = queryArgs[i];
setParameter(namedQuery, i, arg);
}
namedQuery.setLockMode( "obj", lockMode );
return (List<T>) namedQuery.list();
}
@SuppressWarnings("unchecked")
public Iterator<T> executeIterator(Method method, final Object[] queryArgs, LockMode lockMode) {
final String queryName = queryNameFromMethod(method);
final Query namedQuery = getQuery(queryName);
for (int i = 0; i < queryArgs.length; i++) {
Object arg = queryArgs[i];
setParameter(namedQuery, i, arg);
}
namedQuery.setLockMode( "obj", lockMode );
return (Iterator<T>) namedQuery.iterate();
}
@SuppressWarnings("unchecked")
public Long executeCount(Method method, final Object[] queryArgs, LockMode lockMode) {
final String queryName = queryNameFromMethod(method);
final Query namedQuery = getQuery(queryName);
String qString = namedQuery.getQueryString();
if(!qString.trim().toLowerCase().startsWith("from"))
throw new NotImplementedException("GenericHibernate cannot perform count queries on NamedQueries that do NOT start with 'from'. The named query is: " + qString);
String newQuery = "select count(*) " + qString;
Query q = getSession().createQuery(newQuery);
for (int i = 0; i < queryArgs.length; i++) {
Object arg = queryArgs[i];
setParameter(q, i, arg);
}
// don't set the lock mode - we don't want to lock for counts and it causes exceptions anyway.
// q.setLockMode( "obj", lockMode );
Long count = (Long) q.iterate().next();
return count;
}
@SuppressWarnings("unchecked")
public ScrollableResults executeScroller(Method method, final Object[] queryArgs, LockMode lockMode) {
final String queryName = queryNameFromMethod(method);
final Query namedQuery = getQuery(queryName);
for (int i = 0; i < queryArgs.length; i++) {
Object arg = queryArgs[i];
setParameter(namedQuery, i, arg);
}
namedQuery.setLockMode( "obj", lockMode );
return (ScrollableResults) namedQuery.scroll();
}
@SuppressWarnings("unchecked")
public T executeUnique(Method method, final Object[] queryArgs, LockMode lockMode) {
final String queryName = queryNameFromMethod(method);
final Query namedQuery = getQuery(queryName);
for (int i = 0; i < queryArgs.length; i++) {
Object arg = queryArgs[i];
setParameter(namedQuery, i, arg);
}
namedQuery.setLockMode( "obj", lockMode );
Object result = namedQuery.uniqueResult();
return (T) result;
}
private void setParameter(final Query namedQuery, int i, Object arg) {
if( arg instanceof Object[] ) {
namedQuery.setParameterList("param"+i, (Object[]) arg);
} else if( arg instanceof Collection ) {
namedQuery.setParameterList("param"+i, (Collection) arg);
} else {
namedQuery.setParameter("param"+i, arg);
// namedQuery.setParameter(i, arg);
}
}
public String queryNameFromMethod(Method finderMethod) {
String name = finderMethod.getName();
boolean done = false;
while (!done) {
String lname = name.toLowerCase();
if(lname.startsWith(FinderIntroductionInterceptor.COUNT))
name = name.substring(FinderIntroductionInterceptor.COUNT.length());
else if(lname.startsWith(FinderIntroductionInterceptor.FIND))
name = name.substring(FinderIntroductionInterceptor.FIND.length());
else if(lname.startsWith(FinderIntroductionInterceptor.ITERATE))
name = name.substring(FinderIntroductionInterceptor.ITERATE.length());
else if(lname.startsWith(FinderIntroductionInterceptor.LOCK))
name = name.substring(FinderIntroductionInterceptor.LOCK.length());
else if(lname.startsWith(FinderIntroductionInterceptor.SCROLL))
name = name.substring(FinderIntroductionInterceptor.SCROLL.length());
else if(lname.startsWith(FinderIntroductionInterceptor.UNIQUE))
name = name.substring(FinderIntroductionInterceptor.UNIQUE.length());
else
done = true;
}
return persistentClass.getSimpleName() + "." + name;
}
Query getQuery(String queryName) {
if (queryName.toLowerCase().endsWith("all")) {
return getSession().createQuery("from " + persistentClass.getName() + " obj");
} else {
return getSession().getNamedQuery(queryName);
}
}
}