JPA OneToOne not working -

i followed tutorial : http://www.codejava.net/frameworks/hibernate/hibernate-one-to-one-mapping-with-foreign-key-annotations-example

i have following code:

@entity @table(name = domainconstant.table_user) public class user{      @id     @column(name = domainconstant.domain_user_id)     @generatedvalue     private long userid;      private useractivationcode useractivationcode;      ///////////////////// constructor....     /// standard , set....       @onetoone(cascade = cascadetype.all)     @joincolumn(name =  domainconstant.domain_activation_link_id)     public useractivationcode getuseractivationcode() {         return useractivationcode;     } }  @entity @table(name = domainconstant.table_user_activaton_link) public class useractivationcode {      @id     @column(name = domainconstant.domain_activation_link_id)     @generatedvalue     private long useractivationcodeid;      @column(name = domainconstant.domain_activation_date)     @temporal(javax.persistence.temporaltype.date)     private date date;      @column(name = domainconstant.domain_activation_code)     private string code;      ///////////////////// constructor....     /// standard , set....  } 

when save user object not make record in useractivationcode, why?

like this:

user newuser = new user(); newuser.setuseractivationcode(new useractivationcode("this example")); userdao.save(newuser); 

i have record in user table.

can tell me why?

your problem mixing access types. in user entity have specified @id on field (private long userid) whereas have defined join mapping on property (the getter useractivationcode). if specify join mapping on field, should work is.

@entity @table(name = domainconstant.table_user) public class user{      @id     @column(name = domainconstant.domain_user_id)     @generatedvalue     private long userid;      @onetoone(cascade = cascadetype.all)     @joincolumn(name =  domainconstant.domain_activation_link_id)     private useractivationcode useractivationcode;      ///////////////////// constructor....     /// standard , set....       public useractivationcode getuseractivationcode() {         return useractivationcode;     } } 

for more information on access , access types, see access, java ee 7