Failed to create a custom user type using Spring Data JPA

Question

I'm trying to create a custom user type for my database called CompanyType. I will use it to store only one unique String as an identifier for my final object (in code it is LEGAL and INDIVIDUAL).

Full class of CompanyType:

public class CompanyType implements UserType {

    private String typeId;
    private String typeName;

    public static final CompanyType LEGAL = new CompanyType("LEGAL", "Some legal type");
    public static final CompanyType INDIVIDUAL = new CompanyType("INDIVIDUAL", "Some individual type");

    public CompanyType(String typeId, String typeName) {
        this.typeId = typeId;
        this.typeName = typeName;
    }

    public String getTypeId() {
        return typeId;
    }

    public String getTypeName() {
        return typeName;
    }

    @Override
    public int[] sqlTypes() {
        return new int[]{Types.VARCHAR};
    }

    @Override
    public Class returnedClass() {
        return String.class;
    }

    @Override
    public boolean equals(Object o, Object o1) throws HibernateException {
        return o.equals(o1);
    }

    @Override
    public int hashCode(Object o) throws HibernateException {
        return o.hashCode();
    }

    @Override
    public Object nullSafeGet(ResultSet resultSet, String[] strings, SharedSessionContractImplementor sharedSessionContractImplementor, Object o) throws HibernateException, SQLException {
        if(resultSet.getString(strings[0]).equals("LEGAL")) return LEGAL;
        else return INDIVIDUAL;
    }

    @Override
    public void nullSafeSet(PreparedStatement preparedStatement, Object o, int i, SharedSessionContractImplementor sharedSessionContractImplementor) throws HibernateException, SQLException {
        preparedStatement.setString(i, this.getTypeId());
    }

    @Override
    public Object deepCopy(Object o) throws HibernateException {
        CompanyType toCopy = (CompanyType) o;
        return new CompanyType(toCopy.getTypeId(), toCopy.getTypeName());
    }

    @Override
    public boolean isMutable() {
        return true;
    }

    @Override
    public Serializable disassemble(Object o) throws HibernateException {
        return (Serializable) o;
    }

    @Override
    public Object assemble(Serializable serializable, Object o) throws HibernateException {
        return serializable;
    }

    @Override
    public Object replace(Object o, Object o1, Object o2) throws HibernateException {
        return deepCopy(o);
    }
}

And then I'm trying to use it in my entity - Contragent.java

@Entity
public class Contragent {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    private String name;
    private String INN;
    private String OGRN;

    @Type(type = "com.test.test1.CompanyType")
    private CompanyType companyType;

... other code

When I'm running my project, it prints an exception:

2021-03-15 02:15:07.831 ERROR 12824 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Unable to instantiate custom type: com.test.test1.CompanyType
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1786) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:602) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1153) ~[spring-context-5.3.4.jar:5.3.4]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:907) ~[spring-context-5.3.4.jar:5.3.4]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:582) ~[spring-context-5.3.4.jar:5.3.4]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.3.jar:2.4.3]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) ~[spring-boot-2.4.3.jar:2.4.3]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) ~[spring-boot-2.4.3.jar:2.4.3]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) ~[spring-boot-2.4.3.jar:2.4.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) ~[spring-boot-2.4.3.jar:2.4.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1311) ~[spring-boot-2.4.3.jar:2.4.3]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1300) ~[spring-boot-2.4.3.jar:2.4.3]
    at com.test.test1.Test1Application.main(Test1Application.java:11) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.4.3.jar:2.4.3]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Unable to instantiate custom type: com.test.test1.CompanyType
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:421) ~[spring-orm-5.3.4.jar:5.3.4]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.4.jar:5.3.4]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1845) ~[spring-beans-5.3.4.jar:5.3.4]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1782) ~[spring-beans-5.3.4.jar:5.3.4]
    ... 22 common frames omitted
Caused by: org.hibernate.MappingException: Unable to instantiate custom type: com.test.test1.CompanyType
    at org.hibernate.type.TypeFactory.custom(TypeFactory.java:185) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.type.TypeFactory.byClass(TypeFactory.java:78) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.type.TypeResolver.heuristicType(TypeResolver.java:126) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.mapping.SimpleValue.getType(SimpleValue.java:484) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.mapping.SimpleValue.isValid(SimpleValue.java:466) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.mapping.Property.isValid(Property.java:227) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.mapping.PersistentClass.validate(PersistentClass.java:624) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.mapping.RootClass.validate(RootClass.java:267) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.boot.internal.MetadataImpl.validate(MetadataImpl.java:354) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:298) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:468) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1259) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.4.jar:5.3.4]
    at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.4.jar:5.3.4]
    at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.4.jar:5.3.4]
    ... 26 common frames omitted
Caused by: java.lang.InstantiationException: com.test.test1.CompanyType
    at java.base/java.lang.Class.newInstance(Class.java:571) ~[na:na]
    at org.hibernate.type.TypeFactory.custom(TypeFactory.java:177) ~[hibernate-core-5.4.28.Final.jar:5.4.28.Final]
    ... 40 common frames omitted
Caused by: java.lang.NoSuchMethodException: com.test.test1.CompanyType.<init>()
    at java.base/java.lang.Class.getConstructor0(Class.java:3349) ~[na:na]
    at java.base/java.lang.Class.newInstance(Class.java:556) ~[na:na]
    ... 41 common frames omitted


Process finished with exit code 0

Answer 1

I would suggest you to use an enum for this case:

public enum CompanyType {
    LEGAL("Some legal type"),
    INDIVIDUAL("Some individual type");

    private final String name;

    CompanyType(String name)
    {
      this.name = name;
    }

    public String getCompanyName()
    {
       return name;
    }
}

and then use it in this way:

@Entity
public class Contragent {

    // ...

    @Enumerated(EnumType.STRING)
    @Column(name = "company_type")
    private CompanyType companyType;

}