Develop Reference

Boolean defaultValue MapStruct

I'm trying to set a defaultValue for a boolean field using MapStruct, but the generated code simply ignores it.
My code:
public class CreateEventRequest {
#NotNull
#JsonProperty
private Boolean isPrivate;
#JsonProperty
private Boolean friendCanInviteFriends;
#JsonProperty
private boolean showGuestList;
public boolean isPrivate() {
return isPrivate;
}
public String getDescription() {
return description;
}
public boolean isFriendCanInviteFriends() {
return friendCanInviteFriends;
}
public boolean isShowGuestList() {
return showGuestList;
}
}
My mapper:
#Mapper(componentModel = "spring")
public interface CreateEventRequestMapper {
#Mapping(target = "showGuestList", source = "showGuestList", defaultExpression = "java(true)")
#Mapping(target = "friendCanInviteFriends", source = "friendCanInviteFriends", defaultValue = "true")
Event map(CreateEventRequest request);
}
The generated code:
public class CreateEventRequestMapperImpl implements CreateEventRequestMapper {
#Override
public Event map(CreateEventRequest request) {
if ( request == null ) {
return null;
}
Event event = new Event();
event.setShowGuestList( request.isShowGuestList() );
event.setFriendCanInviteFriends( request.isFriendCanInviteFriends() );
event.setPrivate( request.isPrivate() );
return event;
}
}
As you can see, I've tried using primitive/non-primitive type but it simply ignores the defaultValue.
Am I missing something here?
Thanks!

The problem is that the return type of your getter methods in the source object is always primitive which can't be null, you need to return Boolean.
MapStruct doesn't support direct private field access which requires reflection.

Storing Enum custom Values with JPA

I have an enum:
public enum NotificationType {
OPEN("open"),
CLOSED("closed");
public String value;
NotificationType(String value) {
this.value = value;
}
}
I want to pass the custom string open or closed rather than OPEN or CLOSED to entity. Currently, I've mapped it in the entity as follows:
#Enumerated(EnumType.STRING)
private NotificationType notificationType;
Which is the best way to store/ fetch enum value?

You can create a custom converter like this:
#Converter(autoApply = true)
public class NotificationTypeConverter implements AttributeConverter<NotificationType, String> {
#Override
public String convertToDatabaseColumn(NotificationType notificationType) {
return notificationType == null
? null
: notificationType.value;
}
#Override
public NotificationType convertToEntityAttribute(String code) {
if (code == null || code.isEmpty()) {
return null;
}
return Arrays.stream(NotificationType.values())
.filter(c -> c.value.equals(code))
.findAny()
.orElseThrow(IllegalArgumentException::new);
}
}
And perhaps you'll need to remove annotation from your notificationType field so that this converter takes effect.

Yes, basically you have to develop a custom converter for that but I suggest you use Optional to avoid dealing with null and exceptions.
Add in NotificationType:
public static Optional<NotificationType> getFromValue(String value) {
return Optional.ofNullable(value)
.flatMap(dv -> Arrays.stream(NotificationType.values())
.filter(ev -> dv.equals(ev.value))
.findFirst());
}
Create the required converter:
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
#Converter(autoApply = true)
public class NotificationTypeConverter implements AttributeConverter<NotificationType, String> {
#Override
public String convertToDatabaseColumn(NotificationType notificationType) {
return null == notificationType ? null : notificationType.value;
}
#Override
public NotificationType convertToEntityAttribute(String databaseValue) {
return NotificationType.getFromValue(databaseValue)
.orElse(null);
}
}
And now, you only have to modify your model:
#Entity
#Table
public class MyEntity {
#Convert(converter=NotificationTypeConverter.class)
private NotificationType notificationType;
}

Null columns are created on either tables when accessing data using Spring Data JPA

I am new to Spring Data JPA and Hibernate. By looking at different examples I built a working model for CRUD operations on one entity, I am having trouble in joining two tables to extract AF_NAME using AF_ID from another table which is Foreign key. A null column is created with the names of and while accessing, null is returned.please check if I am following preocedure for joins and point me to any tutorial know.
I followed this solution and still there is no progress.
#Entity
#Configuration
#EnableAutoConfiguration
#Table(name = "AFF_CONFIG")
public class AFF_CONFIG implements Serializable {
#Id
#Column(name = "AFF_CONFIG_ID")
private String AFF_CONFIG_ID;
#Column(name = "AFF_ID")
private String AFF_ID;
#Column(name = "CH_ID")
private String CH_ID;
#Column(name = "M_ID")
private Long M_ID;
#Column(name = "KEY")
private String KEY;
#Column(name = "VALUE")
private String VALUE;
#Column(name = "SYSTEM")
private String SYSTEM;
private AFF aff;
#LazyCollection(LazyCollectionOption.TRUE)
#ManyToOne
#JoinColumn(name = "AFF_ID")
public AFF getAff() {
return aff;
}
public void setAffiliate(AFF aff) {
this.aff = aff;
}
public String getAFF_CONFIG_ID() {
return AFF_CONFIG_ID;
}
public void setAFF_CONFIG_ID(String aFF_CONFIG_ID) {
AFF_CONFIG_ID = aFF_CONFIG_ID;
}
public String getAFF_ID() {
return AFF_ID;
}
public void setAFF_ID(String aFF_ID) {
AFF_ID = AFF_ID;
}
public String getCH_ID() {
return CH_ID;
}
public void setCHANNEL_ID(String cH_ID) {
CH_ID = cH_ID;
}
public Long getM_ID() {
return M_ID;
}
public void setM_ID(Long m_ID) {
M_ID = m_ID;
}
public String getKEY() {
return KEY;
}
public void setKEY(String kEY) {
KEY = kEY;
}
public String getVALUE() {
return VALUE;
}
public void setVALUE(String vALUE) {
VALUE = vALUE;
}
public String getSYSTEM() {
return SYSTEM;
}
public void setSYSTEM(String sYSTEM) {
SYSTEM = sYSTEM;
}
Second entity is:
#Entity
#Table(name = "AFF")
public class AFF implements Serializable {
#Column(name = "AFF_NAME")
private String AFF_NAME;
#Column(name = "AFF_CODE")
private String AFF_CODE;
#Id
#Column(name = "AFF_ID")
private String AFF_ID;
private Set<AFF_CONFIG> someAff = new HashSet<AFF_CONFIG>();
#LazyCollection(LazyCollectionOption.TRUE)
#OneToMany(cascade = CascadeType.ALL, mappedBy = "aff")
public Set<AFF_CONFIG> getSomeAff() {
return someAff;
}
public void setSomeAff(Set<AFF_CONFIG> someAff) {
this.someAff = someAff;
}
public String getAFF_ID() {
return AFF_ID;
}
public void setAFF_ID(String aFF_ID) {
AFF_ID = aFF_ID;
}
public String getAFF_NAME() {
return AFF_NAME;
}
public void setAFF_NAME(String aFF_NAME) {
AFF_NAME = aFF_NAME;
}
public String getAFF_CODE() {
return AFF_CODE;
}
public void setAFF_CODE(String aFF_CODE) {
AFF_CODE = aFF_CODE;
}
Since this is many to one relation I created set type in one and object type in another as defined in other places.Created a repository by extending crud and added a query. Excise the bunch of different annotations, I included them in hoping to solve the null entry.
#Repository
public interface MarketRepository extends CrudRepository<AFF_CONFIG,String> {
Page<AFF_CONFIG> findAll(Pageable pageable);
#Query("Select a,b from AFF_CONFIG a, AFF b where a.AFF_ID = b.AFF_ID" )
public List<AFF_CONFIG> getAffData();
}
the applicatoin is working fine even after some tinkering until I Included these annotations. Now there is this error:
Caused by: org.hibernate.MappingException: Could not determine type for: java.util.Set, at table: aff.

I solved the issue with the help of my Supervisor. Looks like we have to follow naming specifications for Class and variables. And one more correction is to remove collection type object and change it to just object (removed set in aff class).I will post the corrected later, to compare and contrast.

How to map multiple parameter names to POJO when binding spring mvc command objects

My question is actually a spin-off of this question as seen here... so it might help to check that thread before proceeding.
In my Spring Boot project, I have two entities Sender and Recipient which represent a Customer and pretty much have the same fields, so I make them extend the base class Customer;
Customer base class;
#MappedSuperclass
public class Customer extends AuditableEntity {
#Column(name = "firstname")
private String firstname;
#Transient
private CustomerRole role;
public Customer(CustomerRole role) {
this.role = role;
}
//other fields & corresponding getters and setters
}
Sender domain object;
#Entity
#Table(name = "senders")
public class Sender extends Customer {
public Sender(){
super.setRole(CustomerRole.SENDER);
}
}
Recipient domain object;
#Entity
#Table(name = "recipients")
public class Recipient extends Customer {
public Recipient(){
super.setRole(CustomerRole.RECIPIENT);
}
}
NOTE - Sender and Recipient are exactly alike except for their roles. These can be easily stored in a single customers Table by making the Customer base class an entity itself, but I intentionally separate the entities this way because I have an obligation to persist each customer type in separate database tables.
Now I have one form in a view that collects details of both Sender & Recipient, so for example to collect the firstname, I had to name the form fields differently as follows;
Sender section of the form;
<input type="text" id="senderFirstname" name="senderFirstname" value="$!sender.firstname">
Recipient section of the form;
<input type="text" id="recipientFirstname" name="recipientFirstname" value="$!recipient.firstname">
But the fields available for a customer are so many that I'm looking for a way to map them to a pojo by means of an annotation as asked in this question here. However, the solutions provided there would mean that I have to create separate proxies for both domain objects and annotate the fields accordingly e.g
public class SenderProxy {
#ParamName("senderFirstname")
private String firstname;
#ParamName("senderLastname")
private String lastname;
//...
}
public class RecipientProxy {
#ParamName("recipientFirstname")
private String firstname;
#ParamName("recipientLastname")
private String lastname;
//...
}
So I got very curious and was wondering, is there a way to map this Proxies to more than one #ParamName such that the base class for example can just be annotated as follows?;
#MappedSuperclass
public class Customer extends AuditableEntity {
#Column(name = "firstname")
#ParamNames({"senderFirstname", "recipientFirstname"})
private String firstname;
#Column(name = "lastname")
#ParamNames({"senderLastname", "recipientLastname"})
private String lastname;
#Transient
private CustomerRole role;
public Customer(CustomerRole role) {
this.role = role;
}
//other fields & corresponding getters and setters
}
And then perhaps find a way to select value of fields based on annotation??

A suggestion from Zhang Jie like ExtendedBeanInfo
so i do it this way
#Target(ElementType.FIELD)
#Retention(RetentionPolicy.RUNTIME)
#Documented
public #interface Alias {
String[] value();
}
public class AliasedBeanInfoFactory implements BeanInfoFactory, Ordered {
#Override
public BeanInfo getBeanInfo(Class<?> beanClass) throws IntrospectionException {
return supports(beanClass) ? new AliasedBeanInfo(Introspector.getBeanInfo(beanClass)) : null;
}
private boolean supports(Class<?> beanClass) {
Class<?> targetClass = beanClass;
do {
Field[] fields = targetClass.getDeclaredFields();
for (Field field : fields) {
if (field.isAnnotationPresent(Alias.class)) {
return true;
}
}
targetClass = targetClass.getSuperclass();
} while (targetClass != null && targetClass != Object.class);
return false;
}
#Override
public int getOrder() {
return Ordered.LOWEST_PRECEDENCE - 100;
}
}
public class AliasedBeanInfo implements BeanInfo {
private static final Logger LOGGER = LoggerFactory.getLogger(AliasedBeanInfo.class);
private final BeanInfo delegate;
private final Set<PropertyDescriptor> propertyDescriptors = new TreeSet<>(new PropertyDescriptorComparator());
AliasedBeanInfo(BeanInfo delegate) {
this.delegate = delegate;
this.propertyDescriptors.addAll(Arrays.asList(delegate.getPropertyDescriptors()));
Class<?> beanClass = delegate.getBeanDescriptor().getBeanClass();
for (Field field : findAliasedFields(beanClass)) {
Optional<PropertyDescriptor> optional = findExistingPropertyDescriptor(field.getName(), field.getType());
if (!optional.isPresent()) {
LOGGER.warn("there is no PropertyDescriptor for field[{}]", field);
continue;
}
Alias alias = field.getAnnotation(Alias.class);
addAliasPropertyDescriptor(alias.value(), optional.get());
}
}
private List<Field> findAliasedFields(Class<?> beanClass) {
List<Field> fields = new ArrayList<>();
ReflectionUtils.doWithFields(beanClass,
fields::add,
field -> field.isAnnotationPresent(Alias.class));
return fields;
}
private Optional<PropertyDescriptor> findExistingPropertyDescriptor(String propertyName, Class<?> propertyType) {
return propertyDescriptors
.stream()
.filter(pd -> pd.getName().equals(propertyName) && pd.getPropertyType().equals(propertyType))
.findAny();
}
private void addAliasPropertyDescriptor(String[] values, PropertyDescriptor propertyDescriptor) {
for (String value : values) {
if (!value.isEmpty()) {
try {
this.propertyDescriptors.add(new PropertyDescriptor(
value, propertyDescriptor.getReadMethod(), propertyDescriptor.getWriteMethod()));
} catch (IntrospectionException e) {
LOGGER.error("add field[{}] alias[{}] property descriptor error", propertyDescriptor.getName(),
value, e);
}
}
}
}
#Override
public BeanDescriptor getBeanDescriptor() {
return this.delegate.getBeanDescriptor();
}
#Override
public EventSetDescriptor[] getEventSetDescriptors() {
return this.delegate.getEventSetDescriptors();
}
#Override
public int getDefaultEventIndex() {
return this.delegate.getDefaultEventIndex();
}
#Override
public PropertyDescriptor[] getPropertyDescriptors() {
return this.propertyDescriptors.toArray(new PropertyDescriptor[0]);
}
#Override
public int getDefaultPropertyIndex() {
return this.delegate.getDefaultPropertyIndex();
}
#Override
public MethodDescriptor[] getMethodDescriptors() {
return this.delegate.getMethodDescriptors();
}
#Override
public BeanInfo[] getAdditionalBeanInfo() {
return this.delegate.getAdditionalBeanInfo();
}
#Override
public Image getIcon(int iconKind) {
return this.delegate.getIcon(iconKind);
}
static class PropertyDescriptorComparator implements Comparator<PropertyDescriptor> {
#Override
public int compare(PropertyDescriptor desc1, PropertyDescriptor desc2) {
String left = desc1.getName();
String right = desc2.getName();
for (int i = 0; i < left.length(); i++) {
if (right.length() == i) {
return 1;
}
int result = left.getBytes()[i] - right.getBytes()[i];
if (result != 0) {
return result;
}
}
return left.length() - right.length();
}
}
}

How to set enum field as Integer via Hibernate to db?

I have integer column as "status" in my db.
My enum class:
public enum MemberStatus {
PASSIVE(0),ACTIVE(1);
private int value;
private MemberStatus(int value) {
this.value = value;
}
public int getValue() {
return value;
}
}
My entity field:
#Column(name = "status", nullable = false)
#Enumerated(EnumType.ORDINAL)
private MemberStatus status;
Hibernate Log:
org.postgresql.util.PSQLException: ERROR: column "status" is of type integer but expression is of type bytea.
Hint: You will need to rewrite or cast the expression.bytea
I use PostgreSQL. How to solve this problem? Any idea?

I suggest you use a converter.
It's the cleanest solution i came to because:
you no longer have an issue with the order in which you add values to
the enum or if you refactor the enum elements name
you have more flexibility on what database type your column has
You can define the field as:
#Column(name = "status", nullable = false)
#Convert(converter = MemberStatusEnumConverter.class)
private MemberStatus status;
The enum becomes simpler:
public enum MemberStatus {
PASSIVE,
ACTIVE;
}
And your converter class MemberStatusEnumConverter:
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
#Converter
public class MemberStatusEnumConverter implements
AttributeConverter<MemberStatus,Integer>{
#Override
public Integer convertToDatabaseColumn(MemberStatus attribute) {
switch (attribute) {
case PASSIVE:
return new Integer(0);
case COUNTYLEVEL:
return new Integer(1);
default:
throw new IllegalArgumentException("Unknown" + attribute);
}
}
#Override
public MemberStatus convertToEntityAttribute(Integer dbData) {
if (dbData == 0){
return MemberStatus.PASSIVE;
} else if (dbData == 1){
return MemberStatus.ACTIVE;
}
else{
throw new IllegalArgumentException("Unknown" + dbData);
}
}
}
This article describes the solution i implemented for your example.