Hibernate persist Map <String, String> without reference to other tables

Question

Could you help me save a line map using Hibernate?

Map values ​​come from the client and are random, so I don’t want to keep a separate table for map values

Exception

Called: org.hibernate.AnnotationException: related class not found: java.lang.String

code

@Entity public class UserConfig { @Id @SequenceGenerator(sequenceName = "CONFIG_SEQ", name = "ConfigSeq", allocationSize = 1) @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "ConfigSeq") private Long id; @ElementCollection(targetClass = String.class) @CollectionTable(name = "MAP") @MapKey(name="key") @Column(name="value") private Map<String, String> map; 

Update

Could you also explain how to persist Map<MyEnum, String> if MyEnum is a MyEnum -mapped class?

Answer 1

According to the specification, you should annotate the following map:

  @ElementCollection(targetClass = String.class) @CollectionTable(name = "MAP") @MapKeyColumn(name="key") @Column(name="value") private Map<String, String> map; 

So @MapKeyColumn instead of @MapKey .

So you should annotate the map if it is defined as:

 private Map<Basic, Basic> map; // (ie Map<String, String>) 

You use the @MapKey annotation when you have a map defined as:

 private Map<Basic, Entity> map; // (ie Map<String, User>) 

And finally, you use the @MapKeyEnumerated annotation when you have a specific map declaration defined:

 private Map<Enumeration, Basic> map; // (ie Map<MyEnum, String>)