Table Players:
ID | name | email | age | ...
1 | 'bob' | null | 23 | ...
This table is where instances of class Player are persisted (one row per instance, no composition etc.).
Having a Hibernate Session, how do I get the row (say with id - the PK - equal to 1) as a Java Map (key = column name, value = cell value) ?
Example usage:
Map<String,String> row = getPlayerByIdAsMap(1);
Use a query with AliasToEntityMapResultTransformer; is verbose but should works with Hibernate property definition and not with JavaBean definition (they can differ).
Map<String,Object> aliasToValueMap =
session.createCriteria(User.class)
.add(Restrictions.idEq(userID))
.setProjection(Projections.projectionList()
.add(Projections.id().as("id"))
// Add others properties
)
.setResultTransformer(AliasToEntityMapResultTransformer.INSTANCE)
.uniqueResult();
A worse approch can be write a custom ResultTransformer that introspect ClassMetadata and try to extract values...
class IntrospectClassMetadata extends BasicTransformerAdapter {
PassThroughResultTransformer rt = PassThroughResultTransformer.INSTANCE;
public Object transformTuple(Object[] tuple, String[] aliases) {
final Object o = rt.transformTuple(tuple, aliases);
ClassMetadata cm = sf.getClassMetadata(o.getClass());
List<String> pns = new ArrayList<String>(Arrays.asList(cm.getPropertyNames()));
Map<String, Object> m = new HashMap<String, Object>();
for(String pn : pns) {
m.put(pn, cm.getPropertyValue(o, pn));
}
m.put(cm.getIdentifierPropertyName(), cm.getIdentifier(o));
return m;
}
}
and use
Map<String,Object> aliasToValueMap =
session.createCriteria(User.class)
.add(Restrictions.idEq(userID))
.setResultTransformer(new IntrospectClassMetadata())
.uniqueResult();
Last chance:
Map<String,Object> map = (Map<String,Object>)s.createSQLQuery("select * from user where id = :id")
.setParameter("id",p.id)
.setResultTransformer(AliasToEntityMapResultTransformer.INSTANCE)
.uniqueResult();
but this doesn't map list,bags and other mapped object, but only raw column names and values...
Map? Could you complete the example with a couple of keystrokes so it's cristal-clear how to use?Map to a table? See stackoverflow.com/questions/21904041/… pleaseMap<String, Player> rather than List<Map<String,Object>>.. and the key to that map is this, lol.
You can use HQL and do a query for selecting the result as a new Map
select new Map(p.id as ID, p.name as name, p.email as email, p.age as age)
from Player p
It will return you a collection of maps, being each one of the maps a row in the query result.
You can use BeanUtils and do something like this:
User user = (User) session.get(User.class, userID);
Map map = BeanUtils.describe(user);
describe adds the class property and reports nested objects as .. objects (I use @Embedded on them) and not as a set of their properties.
