Populate child bean with Transformers.aliasToBean in Hibernate

Question

I have the next couple of beans:

Address { String name; String number; String zipcode; String town; } MyEntity { Address address; String value1; String value2; }

I'm trying to do the next Hibernate query:

private final List<String> propertiesDistinct = Arrays.asList("address.name"); private final List<String> properties = Arrays.asList("address.number", "address.zipcode", "address.town") ProjectionList projectionList = Projections.projectionList(); if (propertiesDistinct != null) { ProjectionList projectionListDistinct = Projections.projectionList(); for (String propertyDistinct : propertiesDistinct) projectionListDistinct.add(Projections.property(propertyDistinct).as(propertyDistinct)); projectionList.add(Projections.distinct(projectionListAgrupar)); } if (properties != null) for (String property : properties) projectionList.add(Projections.property(property).as(property)); criterio.setProjection(projectionList); // MORE FILTERS ON MyEntity FIELDS //... criterio.add(Restrinctions...); // I want to recover the results on my bean MyEntity so I don't have to create a new one criterio.setResultTransformer(Transformers.aliasToBean(MyEntity.class));

Problem:

Caused by: org.hibernate.PropertyNotFoundException: Could not find setter for address.name on class com.entities.MyEntity

I understand that Hibernate is looking for something like:

public String getAddressName() {} // This should be in MyEntity

Instead of:

public String getName() {} // In my Address bean

Ideas about how can I fix this without creating a new bean?

Thanks!

Do you have setAddress(Address address) in MyEntity and all other setters in all beans? — Luca Basso Ricci
– Luca Basso Ricci, Commented Sep 10, 2013 at 7:49

Sami Andoni · Accepted Answer · 2013-09-11 01:20:14Z

22

I wrote a ResultTransformer that can fix your problem. It's name is AliasToBeanNestedResultTransformer, check it out on github.

answered Sep 11, 2013 at 1:20

Sami Andoni

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2 Comments

maqjav Over a year ago

Sami Andoni this is exactly what I was looking for! Thank you very much. Great Transformer :)

sarwar026 Over a year ago

@Sami Andoni: can you give some guideline to develop it for collection (OneToMany relationship)?

Vicky Thakor · Accepted Answer · 2016-03-04 06:05:02Z

Code provided in Github works fine but there is change in import for new versions of hibernate. Its as follow.

org.hibernate.property.PropertyAccessor replaced byorg.hibernate.property.access.spi.PropertyAccess

and

org.hibernate.property.PropertyAccessorFactory replaced by org.hibernate.property.access.internal.PropertyAccessStrategyBasicImpl

So you'll have change the code from

PropertyAccessor accessor = PropertyAccessorFactory.getPropertyAccessor("property"); accessor.getSetter(resultClass, (String)subclassToAlias.get(subclass).get(2)).set(root, subObject, null);

to

PropertyAccess propertyAccess = PropertyAccessStrategyBasicImpl.INSTANCE.buildPropertyAccess(resultClass, (String)subclassToAlias.get(subclass).get(2)); propertyAccess.getSetter().set(root, subObject, null);

Ronny Shibley · Accepted Answer · 2016-05-03 06:40:58Z

AliasToBeanNestedResultTransformer does not handle Nested Multi Level DTOs, so I rewrote one that handles n-level dtos.

Hope this helps.

public class AliasToBeanNestedMultiLevelResultTransformer extends AliasedTupleSubsetResultTransformer { private static final long serialVersionUID = -8047276133980128266L; public boolean isTransformedValueATupleElement(String[] aliases, int tupleLength) { return false; } private boolean initialized; private Class<?> resultClass; private Map<String,Class<?>> clazzMap = new HashMap<>(); private Map<String,Setter> settersMap = new HashMap<>(); public AliasToBeanNestedMultiLevelResultTransformer(Class<?> resultClass) { this.resultClass = resultClass; } public Object transformTuple(Object[] tuples, String[] aliases) { Map<String,Object> nestedObjectsMap = new HashMap<>(); Object result; try { result = resultClass.newInstance(); if (!initialized){ initialized = true; initialize(aliases); } for (int a=0;a<aliases.length;a++){ String alias = aliases[a]; Object tuple = tuples[a]; Object baseObject = result; int index = alias.lastIndexOf("."); if(index>0){ String basePath = alias.substring(0, index); baseObject = nestedObjectsMap.get(basePath); if (baseObject == null){ baseObject = clazzMap.get(basePath).newInstance(); nestedObjectsMap.put(basePath, baseObject); } } settersMap.get(alias).set(baseObject, tuple,null); } for (Entry<String,Object> entry:nestedObjectsMap.entrySet()){ Setter setter = settersMap.get(entry.getKey()); if (entry.getKey().contains(".")){ int index = entry.getKey().lastIndexOf("."); String basePath = entry.getKey().substring(0, index); Object obj = nestedObjectsMap.get(basePath); setter.set(obj, entry.getValue(), null); } else{ setter.set(result, entry.getValue(), null); } } }catch ( InstantiationException | IllegalAccessException e) { throw new HibernateException( "Could not instantiate resultclass: " + resultClass.getName() ); } return result; } private void initialize(String[] aliases) { PropertyAccessor propertyAccessor = new ChainedPropertyAccessor( new PropertyAccessor[] { PropertyAccessorFactory.getPropertyAccessor( resultClass, null ), PropertyAccessorFactory.getPropertyAccessor( "field" ) } ); for (int a=0;a<aliases.length;a++){ String alias = aliases[a]; Class<?> baseClass = resultClass; if (alias.contains(".")){ String[] split = alias.split("\\."); StringBuffer res = new StringBuffer(); for (int i=0;i<split.length;i++){ if (res.length()>0) res.append("."); String item = split[i]; res.append(item); String resString = res.toString(); if (i==split.length-1){ clazzMap.put(resString,baseClass); settersMap.put(resString, propertyAccessor.getSetter(baseClass, item)); break; } Class<?> clazz = clazzMap.get(resString); if (clazz==null){ clazz = propertyAccessor.getGetter(baseClass,item).getReturnType(); settersMap.put(resString, propertyAccessor.getSetter(baseClass, item)); clazzMap.put(resString,clazz); } baseClass = clazz; } } else{ clazzMap.put(alias, resultClass); settersMap.put(alias, propertyAccessor.getSetter(resultClass, alias)); } } }

}

you can add after Object tuple = tuples[a]; if (tuple == null) continue;

Olivier Tonglet · Accepted Answer · 2017-07-26 08:20:42Z

My solution is very basic. It's not as clean as a proper result transformer but it's useful when you just need to do a quick projection for a few properties.

If you get Could not find setter for address.name on class com.entities.MyEntity

It doesn't mean Hibernate is looking for public String getAddressName() {}. Instead it looks for a setter with the impossible "setAddress.name" name.

Instead of .add(Projections.property("address.name"),"address.name")) type a proper setter name as second argument to the .add() method as follows .add(Projections.property("address.name"),"addressName"))

Then, just add a setter on your "MyEntity" root object: "setAddressName".

public void setAddressName(String addressName) { this.address= (this.address==null) ? new Address() : address; this.address.setName(addressName); }

The drawback is that it "dirties" your object with extra methods.

Also posted here.

I tried this approach and it fails with: javax.persistence.PersistenceException: org.hibernate.PropertyNotFoundException: Could not resolve PropertyAccess for addressName on class <class>. It works if I also define a public String getAddressName(), but I do not want to have the getter. I'm using Hibernate 5.3.18.

Ean V · Accepted Answer · 2013-09-10 08:16:08Z

1

Try creating an alias like criterio.createAlias("address", "add"); and then edit your properties to be like Arrays.asList("add.number","add.zipcode", "add.town").

Hope this helps.

answered Sep 10, 2013 at 8:16

Ean V

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4 Comments

maqjav Over a year ago

I tried your solution but I got the next exception:

org.hibernate.QueryException: Criteria objects cannot be created directly on components. Create a criteria on owning entity and use a dotted property to access component property: address

Ean V Over a year ago

Try createCriteria instead of createAlias. I can't test myself.

Ean V Over a year ago

Are you adding your projections to new criteria? Note that createCriteria returns an instance of Criteria. You should set your projections to this new one.

maqjav Over a year ago

Ean thanks for your help, I sholved it with Sami Andoni transformer. Thank you anyway for your time :)

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