问题
I am working on the project which is based on hibernate and spring. I have spent two days but can't figure out why the "lazy exception" error is coming when i call this piece of code:
public MemberUser SendEmail(MemberUser user) throws MailSendingException {
// Check if password will be sent by mail
// Hibernate.initialize(user);
user = fetchService.fetch(user, FETCH);
// user = userDao.load(user.getId(), FETCH);
final MemberGroup group = user.getMember().getMemberGroup();
final boolean sendPasswordByEmail = group.getMemberSettings().isSendPasswordByEmail();
String newPassword = null;
if (sendPasswordByEmail) {
// If send by mail, generate a new password
newPassword = generatePassword(group);
}
// Update the user
user.setPassword(hashHandler.hash(user.getSalt(), newPassword));
user.setPasswordDate(null);
userDao.update(user);
if (sendPasswordByEmail) {
// Send the password by mail
mailHandler.sendResetPassword(user.getMember(), newPassword);
}
return user;
}
This code is basically sending the email to the user for reset password after getting the user information from the db. Exception comes at "user= fetchService.fetch(user, FETCH)", while FETCH is :
private static final Relationship FETCH = RelationshipHelper.nested(User.Relationships.ELEMENT,
Element.Relationships.GROUP);
This is the code of the fetch function ,when the fetch is called this is executed:
@Override
public <E extends Entity> List<E> fetch(final Collection<E> entities, final Relationship... fetch) {
if (entities == null) {
return null;
}
final List<E> result = new ArrayList<E>(entities.size());
for (E entity : entities) {
entity = fetch(entity, fetch);
result.add(entity);
}
return result;
}
These are hibernate classes but I don't have a grip on these .
public class HibernateHelper {
*/
public static class QueryParameter {
private final Object value;
private final String operator;
public QueryParameter(final Object value, final String operator) {
this.value = value;
this.operator = operator;
}
public String getOperator() {
return operator;
}
public Object getValue() {
return value;
}
}
private static Map<Class<? extends Entity>, Set<String>> directPropertiesCache = new HashMap<Class<? extends Entity>, Set<String>>();
public static void addInElementsParameter(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final Entity value) {
if (value != null && value.isPersistent()) {
final String parameterName = getParameterName(namedParameters, path);
hql.append(" and :").append(parameterName).append(" in elements(").append(path).append(") ");
namedParameters.put(parameterName, value);
}
} public static void addInParameterToQuery(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final Collection<?> values) {
if (values != null && !values.isEmpty()) {
final String parameterName = getParameterName(namedParameters, path);
hql.append(" and ").append(path).append(" in (:").append(parameterName).append(") ");
namedParameters.put(parameterName, values);
}
}
/**
* Adds an "in" operator parameter to the HQL query, if the given value is not empty, appending the values to the named parameters map
*/
public static void addInParameterToQuery(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final Object... values) {
if (values != null && values.length > 0) {
addInParameterToQuery(hql, namedParameters, path, Arrays.asList(values));
}
}
/**
* Adds a 'path like %value%' parameter to the HQL query if the given value is not empty, appending the value to the named parameters map
*/
public static void addLikeParameterToQuery(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final String value) {
doAddLike(hql, namedParameters, path, value, false);
}
/**
* Adds a equals parameter to the HQL query, if the given value is not empty, appending the value to the named parameters map
*/
public static void addParameterToQuery(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final Object value) {
addParameterToQueryOperator(hql, namedParameters, path, "=", value);
}
/**
* Adds a custom parameter to the HQL query, if the given parameter is not empty, appending the value to the named parameters map
*/
public static void addParameterToQuery(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final QueryParameter parameter) {
if (parameter != null) {
addParameterToQueryOperator(hql, namedParameters, path, parameter.getOperator(), parameter.getValue());
}
}
/**
* Adds a custom operator parameter to the HQL query, if the given value is not empty, appending the value to the named parameters map
*/
public static void addParameterToQueryOperator(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final String operator, final Object value) {
if (value != null && !"".equals(value)) {
final String parameterName = getParameterName(namedParameters, path);
hql.append(" and ").append(path).append(" ").append(operator).append(" :").append(parameterName).append(" ");
namedParameters.put(parameterName, value);
}
}
/**
* Adds a period test to the HQL query, if the given period is not empty, appending the value to the named parameters map. See {@link Period}, as
* it controls whether the begin and end dates are inclusive / exclusive.
*
*/
public static void addPeriodParameterToQuery(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final Period period) {
addParameterToQuery(hql, namedParameters, path, getBeginParameter(period));
addParameterToQuery(hql, namedParameters, path, getEndParameter(period));
}
/**
* Adds a 'path like value%' parameter to the HQL query if the given value is not empty, appending the value to the named parameters map
*/
public static void addRightLikeParameterToQuery(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, final String value) {
doAddLike(hql, namedParameters, path, value, true);
}
/**
* Appends the join portion on the query to fetch the specified relationships, when appliable
*/
public static void appendJoinFetch(final StringBuilder hql, final Class<? extends Entity> entityType, final String entityAlias, final Collection<Relationship> fetch) {
if (fetch != null) {
final Set<String> directRelationships = getDirectRelationshipProperties(entityType, fetch);
for (final String directRelationship : directRelationships) {
hql.append(" left join fetch ").append(entityAlias).append(".").append(directRelationship).append(" ");
}
}
}
/**
* Appends the order by portion, with the given path lists (with an optional direction, ie: "e.date desc", "e.name", "x.name")
*/
public static void appendOrder(final StringBuilder hql, final Collection<String> paths) {
if (CollectionUtils.isNotEmpty(paths)) {
hql.append(" order by " + StringUtils.join(paths.iterator(), ","));
}
}
/**
* Appends the order by portion, with the given path lists (with an optional direction, ie: "e.date desc", "e.name", "x.name")
*/
public static void appendOrder(final StringBuilder hql, final String... paths) {
if (paths != null && paths.length > 0) {
appendOrder(hql, Arrays.asList(paths));
}
}
/**
* Returns the begin date of the given period, handling null
*/
public static QueryParameter getBeginParameter(final Period period) {
if (period == null) {
return null;
}
Calendar begin = period.getBegin();
if (begin == null) {
return null;
}
// We must consider the time when explicitly set
if (!period.isUseTime()) {
// Truncate the begin date
begin = DateHelper.truncate(begin);
}
String operator = period.isInclusiveBegin() ? ">=" : ">";
return new QueryParameter(begin, operator);
}
/**
* Returns the end date of the given period, handling null
*/
public static QueryParameter getEndParameter(final Period period) {
if (period == null) {
return null;
}
Calendar end = period.getEnd();
if (end == null) {
return null;
}
// We must consider the time when explicitly set
if (!period.isUseTime()) {
// Truncate the end date and set the next day
end = DateHelper.getDayEnd(end);
}
String operator = period.isInclusiveEnd() ? "<=" : "<";
return new QueryParameter(end, operator);
}
/**
* Returns a StringBuilder containing the begin of a single entity select HQL
* @param entityType The entity type to search
* @param entityAlias The entity alias on the query
* @return The StringBuiler
*/
public static StringBuilder getInitialQuery(final Class<? extends Entity> entityType, final String entityAlias) {
return getInitialQuery(entityType, entityAlias, null);
}
/**
* Returns a StringBuilder containing the begin of a single entity select HQL, with the especified fetch relationships, when appliable
* @param entityType The entity type to search
* @param entityAlias The entity alias on the query
* @param fetch The relationships to fetch
* @return The StringBuiler
*/
public static StringBuilder getInitialQuery(final Class<? extends Entity> entityType, final String entityAlias, final Collection<Relationship> fetch) {
final StringBuilder hql = new StringBuilder(" from ").append(entityType.getName()).append(" ").append(entityAlias).append(" ");
appendJoinFetch(hql, entityType, entityAlias, fetch);
hql.append(" where 1=1 ");
return hql;
}
private static void doAddLike(final StringBuilder hql, final Map<String, Object> namedParameters, final String path, String value, final boolean rightOnly) {
value = StringUtils.trimToNull(value);
if (value == null) {
return;
}
// Remove any manually entered '%'
value = StringUtils.trimToNull(StringUtils.replace(value, "%", ""));
if (value == null) {
return;
}
// Assuming the default database collation is case insensitive, we don't need to perform case transformations
if (rightOnly) {
value += "%";
} else {
value = "%" + value + "%";
}
addParameterToQueryOperator(hql, namedParameters, path, "like", value);
}
/**
* Returns a set of properties that will be fetched directly on the HQL
*/
private static Set<String> getDirectRelationshipProperties(final Class<? extends Entity> entityType, final Collection<Relationship> fetch) {
// Populate the direct properties cache for this entity if not yet exists
Set<String> cachedDirectProperties = directPropertiesCache.get(entityType);
if (cachedDirectProperties == null) {
cachedDirectProperties = new HashSet<String>();
final PropertyDescriptor[] propertyDescriptors = PropertyUtils.getPropertyDescriptors(entityType);
// Scan for child -> parent relationships
for (final PropertyDescriptor descriptor : propertyDescriptors) {
if (descriptor.getReadMethod() != null && descriptor.getWriteMethod() != null && Entity.class.isAssignableFrom(descriptor.getPropertyType())) {
// This is a child -> parent relationship. Add it to the cache
cachedDirectProperties.add(descriptor.getName());
}
}
directPropertiesCache.put(entityType, cachedDirectProperties);
}
// Build the properties to add to HQL fetch from a given relationship set
final Set<String> propertiesToAddToFetch = new HashSet<String>();
for (final Relationship relationship : fetch) {
final String name = PropertyHelper.firstProperty(relationship.getName());
if (cachedDirectProperties.contains(name)) {
propertiesToAddToFetch.add(name);
}
}
return propertiesToAddToFetch;
}
/**
* Generates a parameter name
*/
private static String getParameterName(final Map<String, Object> namedParameters, final String propertyName) {
int counter = 1;
// Transform the property in a valid identifier
final StringBuilder sb = new StringBuilder(propertyName.length());
for (int i = 0, len = propertyName.length(); i < len; i++) {
final char c = propertyName.charAt(i);
if (Character.isJavaIdentifierPart(c)) {
sb.append(c);
} else {
sb.append('_');
}
}
final String field = sb.toString();
String parameterName = field.concat("_1");
while (namedParameters.containsKey(parameterName)) {
parameterName = field.concat("_").concat(String.valueOf(++counter));
}
return parameterName;
}
}
This is the error:
org.hibernate.LazyInitializationException: could not initialize proxy - no Session
at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:167)
at nl.strohalm.cyclos.utils.hibernate.HibernateQueryHandler.initialize(HibernateQueryHandler.java:252)
at nl.strohalm.cyclos.dao.FetchDAOImpl.doFetch(FetchDAOImpl.java:80)
at nl.strohalm.cyclos.dao.FetchDAOImpl.fetch(FetchDAOImpl.java:37)
at nl.strohalm.cyclos.services.fetch.FetchServiceImpl.fetch(FetchServiceImpl.java:45)
at nl.strohalm.cyclos.services.access.AccessServiceImpl.SendEmail(AccessServiceImpl.java:1695)
at nl.strohalm.cyclos.services.access.AccessServiceImpl.resetPasswordAndSendAfterExpire(AccessServiceImpl.java:1732)
at com.omnia.payo.scheduling.task.UserLoginInfoSchedulingTask.doRun(UserLoginInfoSchedulingTask.java:43)
at nl.strohalm.cyclos.scheduling.tasks.BaseScheduledTask.run(BaseScheduledTask.java:42)
at nl.strohalm.cyclos.utils.tasks.TaskRunnerImpl$4.run(TaskRunnerImpl.java:193)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at nl.strohalm.cyclos.utils.access.LoggedUser.runAsSystem(LoggedUser.java:285)
at nl.strohalm.cyclos.utils.tasks.TaskRunnerImpl.doRunScheduledTask(TaskRunnerImpl.java:190)
at nl.strohalm.cyclos.utils.tasks.TaskRunnerImpl.doRunScheduledTask(TaskRunnerImpl.java:170)
at nl.strohalm.cyclos.utils.tasks.TaskRunnerImpl$ScheduledTaskThreads.process(TaskRunnerImpl.java:64)
at nl.strohalm.cyclos.utils.tasks.TaskRunnerImpl$ScheduledTaskThreads.process(TaskRunnerImpl.java:1)
at nl.strohalm.cyclos.utils.ParallelTask$1.process(ParallelTask.java:43)
at nl.strohalm.cyclos.utils.WorkerThreads$WorkerThread$1.call(WorkerThreads.java:53)
at nl.strohalm.cyclos.utils.WorkerThreads$WorkerThread$1.call(WorkerThreads.java:1)
at nl.strohalm.cyclos.utils.access.LoggedUser.runAsSystem(LoggedUser.java:285)
at nl.strohalm.cyclos.utils.WorkerThreads$WorkerThread.run(WorkerThreads.java:49)
Code for doFetch in FetchDAOImpl is:
private <E extends Entity> E doFetch(final E inputEntity, final Relationship... fetch) {
if (inputEntity == null || inputEntity.getId() == null) {
throw new UnexpectedEntityException();
}
E entity;
// Discover the entity real class and id
final Class<? extends Entity> entityType = EntityHelper.getRealClass(inputEntity);
final Long id = inputEntity.getId();
// Load and initialize the entity
try {
entity = (E) getHibernateTemplate().load(entityType, id);
entity = (E) hibernateQueryHandler.initialize(entity);
} catch (final ObjectRetrievalFailureException e) {
throw new EntityNotFoundException(entityType, id);
} catch (final ObjectNotFoundException e) {
throw new EntityNotFoundException(entityType, id);
}
// ... and fetch each relationship
if (!ArrayUtils.isEmpty(fetch)) {
for (final Relationship relationship : fetch) {
if (relationship == null) {
continue;
}
try {
final String name = relationship.getName();
Object bean = entity;
String first = PropertyHelper.firstProperty(name);
String nested = PropertyHelper.nestedPath(name);
while (bean != null && first != null) {
final Object value = hibernateQueryHandler.initializeProperty(bean, first);
bean = value;
first = PropertyHelper.firstProperty(nested);
nested = PropertyHelper.nestedPath(nested);
}
} catch (final PropertyException e) {
// Ok - nonexisting property. Probably fetching a relationship that only exists in one of the subclasses, and trying to use it no
// another one
} catch (final Exception e) {
throw new PropertyException(entity, relationship.getName(), e);
}
}
}
return entity;
}
please someone help me ,i'll be really thankful.
回答1:
This should be helpfull :
What is OpenSessionInViewFilter And How
and
Hibernate updating from different sessions
or this for experts
https://stackoverflow.com/a/32046337/3252285
来源：https://stackoverflow.com/questions/32200474/could-not-initialize-proxy-no-session-exception