java - Way to use @Convert to convert key of a Map (JPA)? -

i using java.time.localdate of java 8, , want convert sql date can persisted. here converter:

@converter(autoapply = true) public class localdatepersistenceconverter implements     attributeconverter<localdate, date> {          @override         public date converttodatabasecolumn(localdate attribute) {         return java.sql.date.valueof(attribute);         }          @override         public localdate converttoentityattribute(date dbdata) {         return dbdata.tolocaldate();         }  } 

here how getting used:

@entity @access(accesstype.field) public class mutualfund implements serializable {      @id     private final string schemename;      @convert(attributename="key",converter=localdatepersistenceconverter.class)     @elementcollection     private map<localdate, price> nav;      //other fields , methods } 

when try persist mutualfund object, following exception:

java.lang.illegalstateexception: @convert placed on map attribute [mypackage.mutualfund.nav] must define attributename of 'key' or 'value' 

what wrong in code? please help. thanks.

your mapping of map not completed getting exception.

there 2 options map mapping, not sure 1 trying achieve.

a) localdate key of nav map field of price object:

@embeddable public class price implements serializable {     @convert(converter=localdatepersistenceconverter.class)      //you don't need @convert if annotated @converter(autoapply = true)     public localdate mark;     public double price; } 

then in collection mapping need specify key field used:

@elementcollection @mapkey(name="mark") public map<localdate, price> nav; 

b) key element of nav not part of price object, need explicity map column:

@embeddable public class price implements serializable {     public double price; } 

and map annotation:

@convert(converter=localdatepersistenceconverter.class) @elementcollection @mapkeycolumn(name="mark") public map<localdate, price> nav; 

edit turned out hibernate demanding eclipselink

with @converter(autoapply = true) works without pointing converter both explicit , implicit key column.

@elementcollection @mapkeycolumn(name="mark") //this annotation can omitted key column called nav_key public map<localdate, price> nav; 

i not make work without autoapply. persistence context build if converter declared attributename="key.":

@convert(attributename="key.", converter=localdatepersistenceconverter.class) @elementcollection public map<localdate, price> nav = new hashmap<>(); 

but converter not correctly apllied. during schema generation key column tried generated blob (and failed no length given) , serializaton instead of conversion triggered during insert/fetching. not find way fix it.