Is there any way to project multiple values for an root entity object using Criteria?
Assume we have these classes (With the proper mappings):
class Boss {
private String name;
private List<Employee> employees;
// setters and getters and more stuff
}
class Employee {
private String name;
// setters and getters and more stuff
}
Then i am trying to do this :
public void test() {
Criteria criteria = this.getSession().createCriteria(Boss.class);
criteria.createAlias("employees","employees");
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.property("name"), "name");
projectionList.add(Projections.property("employees.name"), "subordinatesNames");
criteria.setProjection(projectionList);
criteria.setResultTransformer(new AliasToBeanResultTransformer(BossBean.class));
List<BossBean> results = criteria.list(); // fails here
for (BossBean bossBean : results) {
System.out.println (bossBean);
}
}
This is how the Bean looks like (nothign special, just for grouping values) :
public static class BossBean {
private String name;
private List<Strings> subordinatesNames;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<Strings> getSubordinatesNames() {
return subordinatesNames;
}
public void setSubordinatesNames(List<Strings> subordinatesNames) {
this.subordinatesNames = subordinatesNames;
}
}
The exception is this :
2014-06-06 13:37:38 [main] ERROR org.hibernate.property.BasicPropertyAccessor - expected type: java.util.List, actual value: java.lang.String.
I Guess is trying to fit the String returned from Boss(root object) -> (A)Employee(association) ->name(value) into a List.
I want to auto magically get all inserted in the List. Is there a way to achieve this using Criteria? If not, how i can achieve it?
Thanks in advance!
Grettings
Víctor
Related
I try to map my DTO objects to my JPA entities. I have a Collection of children in my ParentEntity. They can be added addChild(). Using the Adder is supported by Mapstruct via the CollectionMappingStrategy (http://mapstruct.org/documentation/dev/reference/html/#collection-mapping-strategies).
This works fine if I create new entities, but fails to clear the children on updating before adding the new children.
The Mapstruct manual says (http://mapstruct.org/documentation/dev/reference/html/#updating-bean-instances):
Collection- or map-typed properties of the target bean to be updated will be cleared and then populated with the values from the corresponding source collection or map.
What am I missing? Is there an additional option I have to set? There is a full example with test case to reproduce the problem at https://github.com/davidfuhr/mapstruct-jpa-child-parent
Here are the classes:
public class ParentEntity {
private String name;
private List<ChildEntity> children = new ArrayList<>();
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<ChildEntity> getChildren() {
return children;
}
public void addChild(ChildEntity child) {
children.add(child);
child.setMyParent(this);
}
public void removeChild(ChildEntity child) {
children.remove(child);
child.setMyParent(null);
}
}
public class ChildEntity {
private String name;
private ParentEntity myParent;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public ParentEntity getMyParent() {
return myParent;
}
public void setMyParent(ParentEntity myParent) {
this.myParent = myParent;
}
}
public class ParentDto {
private String name;
private List<ChildDto> children;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<ChildDto> getChildren() {
return children;
}
public void setChildren(List<ChildDto> children) {
this.children = children;
}
}
public class ChildDto {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
#Mapper(collectionMappingStrategy = CollectionMappingStrategy.ADDER_PREFERRED)
public interface SourceTargetMapper {
SourceTargetMapper MAPPER = Mappers.getMapper(SourceTargetMapper.class);
ParentEntity toEntity(ParentDto s);
ParentEntity updateEntity(ParentDto s, #MappingTarget ParentEntity e);
#Mapping(target = "myParent", ignore = true)
ChildEntity toEntity(ChildDto s);
}
The text in the documentation need to be rephrased. The problem is that especially for collections, there's no good way to handle this out of the box in MapStruct. I'm currently writing some new text for the documentation.
Consider this (when thinking what MapStruct should do for updating collections in general):
What if there's no match: should the non-matching elements be removed?
Should the non matching source elements be added?
What exactly constitutes to a match: equals? hashcode? comparator==0?
Can there be more than one match (Lists, but also depending on what is considered a match.)
How should the resulting collection be sorted?
Should a newly created object be added to a persistence context?
What about JPA child-parent relations?
About the latter one, Dali (Eclipse) also generates remove methods. So should MapStruct call these in the light of the above?
At this moment it works like this: whenever the user wants a collection update method, MapStruct generates a regular call to element mappings (in stead of an update call), because it is the only sensible thing to do. All the remainder is highly dependent on the use-case. If you need to clear the collection at before hand, use the #BeforeMapping to clear it.
Note: I just fixed an issue that handles also adders in this fashion in stead of the vague error message you get now.
If you want a nice way to handle child/parent relations and integrate them with JPA.. have a look at the examples.
Hi Spring and Hibernate experts!
Can any one say if it is possible to use SQL IN-clause in custom #Query in CrudRepository while the Arraylist or set of strings is passed as parameter?
I am relatively new to Spring and do not quite figure out why I get the following Spring error:
"java.lang.IllegalArgumentException: Parameter value [d9a873ed-3f15-4af5-ab1b-9486017e5611] did not match expected type [IoTlite.model.Device (n/a)]"
In this post (JPQL IN clause: Java-Arrays (or Lists, Sets...)?) the subject is discussed pretty closely but I cannot make the suggested solution to work in my case with custom #Query.
My demo repository as part of the spring boot restful application is the following:
#Repository
public interface DeviceRepository extends JpaRepository<Device, Long> {
#Query("SELECT d FROM Device d WHERE d IN (:uuid)")
List<Device> fetchUuids(#Param("uuid") Set<String> uuid);
}
And the model-class is the following:
#Entity
#SequenceGenerator(sequenceName = "device_seq", name = "device_seq_gen", allocationSize = 1)
#JsonIgnoreProperties(ignoreUnknown = true)
public class Device implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "device_seq_gen")
#JsonIgnore
private Integer id;
#Column(unique=true, length=36)
#NotNull
private String uuid = UUID.randomUUID().toString();
#Column(name="name")
private String name;
#JsonInclude(JsonInclude.Include.NON_NULL)
private String description;
#OneToMany(
mappedBy="device",
cascade = CascadeType.ALL,
orphanRemoval = true
)
private List<Sensor> sensors = new ArrayList<>();
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
#JsonIgnore
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getDeviceUuid() {
return uuid;
}
public void setDeviceUuid(String deviceUuid) {
this.uuid = deviceUuid;
}
public List<Sensor> getSensors() {
return sensors;
}
public void addSensor(Sensor sensor){
sensor.setDevice(this);
sensors.add(sensor);
}
}
An here is the relevant part of the service calling the fetchUuids-custom-method with set-list of strings as parameter (service naturally being called by the relevant restcontroller):
#Service
public class DeviceService implements IDeviceService {
#Autowired
private DeviceRepository deviceRepository;
...
#Override
public List<Device> listDevices(Set<String> clientIds) {
return deviceRepository.fetchUuids(clientIds);
}
...
}
Quick fix
You have WHERE d IN (:uuid) in the custom query. You cannot match d, which is an alias for Device entity with :uuid parameter, which is a collection of Strings.
WHERE d.uuid IN (:uuid) would fix the query - it matches a String with Strings.
What you should do instead
It's rather misleading to name the method fetchUuids and return a list of Device instances. It's also unnecessary to write a custom query to do that. You can benefor from repository method name conventions and let Spring Data Jpa framework generate the query for you:
List<Device> findByUuidIn(Set<String> uuids);
You can write in this way
#Query(value = "select name from teams where name in :names", nativeQuery = true)
List<String> getNames(#Param("names") String[] names);
and call the function in service and pass an array of String as arguments.like this
String[] names = {"testing team","development team"};
List<String> teamtest = teamRepository.getNames(names);
Yes is possible to using collection in JPA query parameters.
Your query is wrong, it should be like this:
#Query("SELECT d FROM Device d WHERE d.uuid IN :uuid")
I have got two immutable bean classes for which I am using Orika mapping to copy the values from one to other.
However, when I am trying to copy the unmodifiableList through Orika mapping, it fails by throwing below exception:
java.lang.UnsupportedOperationException
at ma.glasnost.orika.ExceptionUtility.newMappingException(ExceptionUtility.java:55)
at ma.glasnost.orika.impl.MapperFacadeImpl.map(MapperFacadeImpl.java:681)
at ma.glasnost.orika.impl.MapperFacadeImpl.map(MapperFacadeImpl.java:650)
at com.myproject.OrikaTest.testEmployeeMapping
I have provided the code below with which you can replicate the same issue:
EmployeeDto class:
public final class EmployeeDto {
private final int id;
private final String name;
private final List<String> previousGrades;
public EmployeeDto(int id, String name, List<String> previousGrades) {
this.id = id;//validations removed
this.name = name;//validations removed
//Commented unmodifiableList as it does not work
//this.previousGrades = Collections.unmodifiableList(previousGrades);
this.previousGrades = previousGrades;
}
public int getId() {
return id;
}
public String getName() {
return name;
}
public List<String> getPreviousGrades() {
//tried like this, even this does not work
return Collections.unmodifiableList(previousGrades);
}
}
Employee class:
public final class Employee {
//ditto AS EmployeeDto
}
OrikaTest class:
public class OrikaTest {
private static final MapperFactory mapperFactory =
new DefaultMapperFactory.Builder().build();
private static final MapperFacade mapperFacade =
mapperFactory.getMapperFacade();
#Test
public void testEmployeeMapping() {
List<String> employeeGrades = Arrays.asList("A", "B");
Employee employee = new Employee(1234, "John", employeeGrades);
EmployeeDto employeeDto = mapperFacade.map(employee, EmployeeDto.class);
//tests using assertEquals
Assert.assertEquals(employeeGrades, employeeDto.getPreviousGrades());
}
}
I could find a link here on this subject, but it was not that clear as alternatives were not explained properly.
So, can you help with an example or any workaround on how to copy the unmodifiableList through Orika mapping?
If the case is that Orika must be able to mutate the list components of the mapped objects then the following could be a work around:
Add a freeze method to your objects. When the objects are created they are in a mutable state. After freeze has been called it is no longer possible to mutate the objects.
It could be implemented like this:
public final class EmployeeDto {
private final int id;
private final String name;
private List<String> previousGrades;
public EmployeeDto(int id, String name, List<String> previousGrades) {
this.id = id;//validations removed
this.name = name;//validations removed
this.previousGrades = previousGrades;
}
public void freeze() {
previousGrades = Collections.unmodifiableList(previousGrades)
}
public List<String> getPreviousGrades() {
return previousGrades;
}
}
i want to update/replace document using id field only, i am using mongoTemplate.save(p, collection) method but i am getting DuplicateKeyException: error code 11000 and error message 'E11000'
public class MongoDAO {
#Autowired
#Qualifier("mongoTemplate")
private MongoTemplate mongoTemplate;
private static final String PERSON_COLLECTION = "person";
public MongoTemplate getMongoTemplate() {
return mongoTemplate;
}
public void update(Object p) {
this.mongoTemplate.save(p, PERSON_COLLECTION);
}
}
This is my person DAO
public class PersonDAO{
#Autowired
MongoDAO mongoDAO;
public void updatePerson(){
//read
Person p1 = mongoDAO.readById("1234");
//update
p1.setName("David");
mongoDAO.update(p1);
}
}
Person.java class
package com.mongo.andy;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Field;
public class Person {
#Id
private String id;
#Field
private String name;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
I simply want to get the object from mongodb change the values and update the document based on _id
Using mongooperation.save() or mongotemplate.save() i am getting below error
com.mongodb.DuplicateKeyException: Write failed with error code 11000 and error message 'E11000 duplicate key error collection: Person.person index: _id_ dup key: { : "5996f1d43b6af5c797a1cf4g" }'
at com.mongodb.operation.BaseWriteOperation.convertBulkWriteException(BaseWriteOperation.java:236)
at com.mongodb.operation.BaseWriteOperation.access$300(BaseWriteOperation.java:60)
at com.mongodb.operation.BaseWriteOperation$1.call(BaseWriteOperation.java:146)
at com.mongodb.operation.BaseWriteOperation$1.call(BaseWriteOperation.java:133)
at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:230)
at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:221)
at com.mongodb.operation.BaseWriteOperation.execute(BaseWriteOperation.java:133)
at com.mongodb.operation.BaseWriteOperation.execute(BaseWriteOperation.java:60)
at com.mongodb.Mongo.execute(Mongo.java:781)
at com.mongodb.Mongo$2.execute(Mongo.java:764)
at com.mongodb.DBCollection.executeWriteOperation(DBCollection.java:333)
at com.mongodb.DBCollection.insert(DBCollection.java:328)
at com.mongodb.DBCollection.insert(DBCollection.java:319)
at com.mongodb.DBCollection.insert(DBCollection.java:289)
at com.mongodb.DBCollection.insert(DBCollection.java:255)
at com.mongodb.DBCollection.insert(DBCollection.java:192)
at org.springframework.data.mongodb.core.MongoTemplate$9.doInCollection(MongoTemplate.java:1051)
at org.springframework.data.mongodb.core.MongoTemplate.execute(MongoTemplate.java:479)
at org.springframework.data.mongodb.core.MongoTemplate.insertDBObject(MongoTemplate.java:1046)
at org.springframework.data.mongodb.core.MongoTemplate.doInsert(MongoTemplate.java:855)
at org.springframework.data.mongodb.core.MongoTemplate.doSaveVersioned(MongoTemplate.java:1001)
at org.springframework.data.mongodb.core.MongoTemplate.save(MongoTemplate.java:985)
at com.mcmcg.dia.account.metadata.dao.MongoDAO.update(MongoDAO.java:105)
at com.mcmcg.dia.account.metadata.service.AccountOALDService.mongotestapi(AccountOALDService.java:265)
at com.mcmcg.dia.account.metadata.service.AccountOALDService$$FastClassBySpringCGLIB$$7f85f843.invoke(<generated>)
Please provide the solution and suggest if there is any other way to update/replace documents in mongodb using spring-data on the basis of id field only. I have large custom object and not interesting writing any queries for update.
I was able to do so in couchbase db using upsert(), finding similar way in mongodb.
Instead of this.mongoTemplate.save(p, PERSON_COLLECTION); try with:
public void update(Object p) {
BasicDBObject dbObject = new BasicDBObject();
mongoTemplate.getConverter().write(p, dbObject);
mongoTemplate.upsert(new Query(Criteria.where("_id").is(((Person) p).getId())),
Update.fromDBObject(dbObject, "_id"), PERSON_COLLECTION);
}
The solution is similar to how the upsert method it is implemented in MongoTemplate.
I have a Base Class.
#Data
class BaseDocument{
String id;
String name;
//Other fields
}
Say I have many classes that extends BaseDocument one below.
class NoteDocument extends BaseDocument{
String description;
Long lastModifiedDate;
//etc
}
It does not make sense to me to send entire document to UI in some cases. Most of the cases I need only id and name.
So for every document I have a VO class.
#Data
class BaseVO {
private String id;
private String name;
}
#Data
class NoteVO extends BaseVO{
//Nothing here now
}
And in NoteDocument I have.
public NoteVO getVo(){
Assert.notNull(getId());
NoteVO noteVo = new NoteVO();
noteVo.setName(getName());
noteVo.setId(getId());
return noteVo;
}
Now I have to copy this method in all the classes that extends BaseDocument.
Instead, I changed my BaseDocument like below.
#Data
class BaseDocument<V extends BaseVO>{
String id;
String name;
public V getVo(Class className) {
Assert.notNull(getId());
V vo = null;
try {
vo = (V) className.newInstance();
vo.setName(getName());
vo.setId(getId());
} catch (IllegalAccessException|InstantiationException e){
e.printStackTrace();
}
Assert.notNull(vo);
return vo;
}
}
I am new to generics. My first question, is this a good practice. Are there any problems in using reflection to create instance, any performance issues? Is there any better way to do achieve (write less code) this.
Edit: Suppose I need to display note in UI, Along with note I need to display name of the User who created note. I am using mongodb, when I save the note I also save UserVO in note, which will have user id and name of the user. If I save only user id while saving the note, I will have to do one more query to get the name of user while displaying. I want to avoid this.
Do not use reflection; use inheritance and maybe covariant return types instead. It will be faster, clearer, more precise, and easier to maintain. You may also find it useful to add methods to populate your VOs incrementally. I didn't come up with a clean way to apply generics to this situation, but I don't think you need them:
class BaseVO {
String id;
String name;
void setId(String id) {
this.id = id;
}
void setName(String name) {
this.name = name;
}
}
class NoteVO extends BaseVO {
// ...
}
#Data
class BaseDocument {
String id;
String name;
//Other fields
protected void populateBaseVO(BaseVO vo) {
vo.setId(id);
vo.setName(name);
}
public BaseVO getVO() {
BaseVO vo = new BaseVO();
populateBaseVO(vo);
return vo;
}
}
#Data
class NoteDocument extends BaseDocument {
String description;
Long lastModifiedDate;
// ....
protected void populateNoteVO(NoteVO vo) {
populateBaseVO(vo);
// ...
}
public NoteVO getVO() {
NoteVO vo = new NoteVO();
populateNoteVO(vo);
return vo;
}
}