Inject another Sling model from Sling Model - aem

2 Sling Models are given and I want to inject one of them. Is this possible with an annotation or do I need to create a PostContruct method as a workaround?
Example:
Model A
#Model(adaptables = Resource.class)
public class ModelA {
#ValueMapValue(name = "jcr:title", injectionStrategy = InjectionStrategy.OPTIONAL)
private String title;
#Inject // Not working!
private ModelB modelB;
}
Model B
#Model(adaptables = Resource.class)
public class ModelB {
#ValueMapValue(injectionStrategy = InjectionStrategy.OPTIONAL)
private String text;
}

Since 1.1.0 version of Sling Models you can use #Self annotation to inject models which can be adapted from current adaptable. In this case from Resource of ModelA.
Injects the adaptable object itself (if the class of the field matches or is a supertype). If the #Self annotation is present it is tried to adapt the adaptable to the field type.
#Model(adaptables = Resource.class)
public class ModelA {
#ValueMapValue(name = "jcr:title", injectionStrategy = InjectionStrategy.OPTIONAL)
private String title;
#Inject // This should works
#Self
private ModelB modelB;
}

You wont be able to inject ModelB into ModelA, what you can do is get the resource instance in ModelA and adapt it to ModelB
#Model(adaptables = SlingHttpServletRequest.class, defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL)
public class ModelA {
#Inject
#Via("resource")
#Named("jcr:title")
private String title;
#Inject
private Resource resource;
#PostConstruct
public void init() {
final ModelB modelb = resource.adaptTo(ModelB.class);
}
}

Related

Dynamic injection using #SpringBean in wicket

I have a form that based on collected information generates a report. I have multiple sources from which to generate reports, but the form for them is the same. I tried to implement strategy pattern using an interface implementing report generator services, but that led to wicket complaining about serialization issues of various parts of the report generator. I would like to solve this without duplicating the code contained in the form, but I have not been able to find information on dynamic injection with #SpringBean.
Here is a rough mock up of what I have
public class ReportForm extends Panel {
private IReportGenerator reportGenerator;
public ReportForm(String id, IReportGenerator reportGenerator) {
super(id);
this.reportGenerator = reportGenerator;
final Form<Void> form = new Form<Void>("form");
this.add(form);
...
form.add(new AjaxButton("button1") {
private static final long serialVersionUID = 1L;
#Override
protected void onSubmit(AjaxRequestTarget target)
{
byte[] report = reportGenerator.getReport(...);
...
}
});
}
}
If I do it this way, wicket tries to serialize the concrete instance of reportGenerator. If I annotate the reportGenerator property with #SpringBean I receive Concrete bean could not be received from the application context for class: IReportGenerator
Edit: I have reworked implementations of IRerportGenerator to be able to annotate them with #Component and now I when I use #SpringBean annotation I get More than one bean of type [IReportGenerator] found, you have to specify the name of the bean (#SpringBean(name="foo")) or (#Named("foo") if using #javax.inject classes) in order to resolve this conflict. Which is exactly what I don't want to do.
I think the behavior you're trying to achieve can be done with a slight workaround, by introducing a Spring bean that holds all IReportGenerator instances:
#Component
public class ReportGeneratorHolder {
private final List<IReportGenerator> reportGenerators;
#Autowired
public ReportGeneratorHolder(List<IReportGenerator> reportGenerators) {
this.reportGenerators = reportGenerators;
}
public Optional<IReportGenerator> getReportGenerator(Class<? extends IReportGenerator> reportGeneratorClass) {
return reportGenerators.stream()
.filter(reportGeneratorClass::isAssignableFrom)
.findAny();
}
}
You can then inject this class into your Wicket page, and pass the desired class as a constructor-parameter. Depending on your Spring configuration you might need to introduce an interface for this as well.
public class ReportForm extends Panel {
#SpringBean
private ReportGeneratorHolder reportGeneratorHolder;
public ReportForm(String id, Class<? extends IReportGenerator> reportGeneratorClass) {
super(id);
IReportGenerator reportGenerator = reportGeneratorHolder
.getReportGenerator(reportGeneratorClass)
.orElseThrow(IllegalStateException::new);
// Form logic omitted for brevity
}
}
As far as I am able to find, looking through documentation and even the source for wicket #SpringBean annotation, this isn't possible. The closest I got is with explicitly creating a proxy for a Spring bean based on class passed. As described in 13.2.4 Using proxies from the wicket-spring project chapter in Wicket in Action.
public class ReportForm extends Panel {
private IReportGenerator reportGenerator;
private Class<? extends IReportGenerator> classType;
private static ISpringContextLocator CTX_LOCATOR = new ISpringContextLocator() {
public ApplicationContext getSpringContext() {
return ((MyApplication)MyApplication.get()).getApplicationContext();
}
};
public ReportForm(String id, Class<? extends IReportGenerator> classType) {
super(id);
this.classType = classType;
final Form<Void> form = new Form<Void>("form");
this.add(form);
...
form.add(new AjaxButton("button1") {
private static final long serialVersionUID = 1L;
#Override
protected void onSubmit(AjaxRequestTarget target)
{
byte[] report = getReportGenerator().getReport(...);
...
}
});
}
private <T> T createProxy(Class<T> classType) {
return (T) LazyInitProxyFactory.createProxy(classType, new
SpringBeanLocator(classType, CTX_LOCATOR));
}
private IReportGenerator getReportGenerator() {
if (reportGenerator = null) {
reportGenerator = createProxy(classType);
}
return reportGenerator;
}
}

InvalidDefinitionException: Cannot construct instance of `com.vehicle.datatransferobject.VehicleDTO`

In the REST endpoint I'm building in Spring Boot, I'm trying to pass my vehicleDTO to my controller. But before it reaches my controller, there is an error.
InvalidDefinitionException: Cannot construct instance of
com.vehicle.datatransferobject.VehicleDTO (no Creators, like default
construct, exist): cannot deserialize from Object value (no delegate-
or property-based Creator)
vehicleDTO
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.myvehicle.EngineType;
#JsonInclude(JsonInclude.Include.NON_NULL)
public class VehicleDTO {
#JsonIgnore
private Long id;
#NotNull(message = "vehiclenumber can not be null!")
private String vehiclenumber;
#Min(2)
#NotNull(message = "Seat count can not be less than 2!")
private Integer vehicleseatcount;
#NotNull(message = "Engine Type can not be null!")
private EngineType enginetype;
#Max(5)
private Integer vehiclerating;
private VehicleDTO(Long id, String vehiclenumber, Integer vehicleseatcount, EngineType enginetype,Integer vehiclerating){
this.vehiclenumber=vehiclenumber;
this.vehicleseatcount=vehicleseatcount;
this.enginetype=enginetype;
this.vehiclerating=vehiclerating;
this.id=id;
}
public static VehicleDTOBuilder newBuilder()
{
return new VehicleDTOBuilder();
}
#JsonProperty
public Long getId() {
return id;
}
public String getvehiclenumber() {
return vehiclenumber;
}
public Integer getvehicleseatcount() {
return vehicleseatcount;
}
public EngineType getEnginetype() {
return enginetype;
}
public Integer getvehiclerating() {
return vehiclerating;
}
public static class VehicleDTOBuilder{
private Long id;
private String vehiclenumber;
private Integer vehicleseatcount;
private EngineType enginetype;
private Integer vehiclerating;
public VehicleDTOBuilder setId(Long id) {
this.id = id;
return this;
}
public VehicleDTOBuilder setvehiclenumber(String vehiclenumber) {
this.vehiclenumber = vehiclenumber;
return this;
}
public VehicleDTOBuilder setvehicleseatcount(Integer vehicleseatcount) {
this.vehicleseatcount = vehicleseatcount;
return this;
}
public VehicleDTOBuilder setEnginetype(EngineType enginetype) {
this.enginetype = enginetype;
return this;
}
public VehicleDTOBuilder setvehiclerating(Integer vehiclerating) {
this.vehiclerating = vehiclerating;
return this;
}
public VehicleDTO createVehicleDTO()
{
return new VehicleDTO(id, vehiclenumber, vehicleseatcount, enginetype,vehiclerating);
}
}
}
My DTO has an Enum type called EngineType
public enum EngineType {
ELECTRIC, DIESEL
}
My controller looks like this
#PostMapping
#ResponseStatus(HttpStatus.CREATED)
public VehicleDTO addvehicle(#Valid #RequestBody VehicleDTO vehicleDTO)
{
VehicleDO vehicleDO = Mapper.VehicleDO(vehicleDTO);
return Mapper.makeVehicleDTO(Service.addvehicle(vehicleDO));
}
This exception :
InvalidDefinitionException: Cannot construct instance of
com.vehicle.datatransferobject.VehicleDTO (no Creators, like default
construct, exist): cannot deserialize from Object value (no delegate-
or property-based Creator)
means that Jackson didn't find a way to instantiate VehicleDTO that is the default constructor (no arg constructor) or a JsonCreator.
As you use a builder pattern you will configure the VehicleDTO class to make Jackson to instantiate VehicleDTO with the VehicleDTOBuilder such as :
#JsonDeserialize(builder = VehicleDTO.VehicleDTOBuilder.class)
public class VehicleDTO {
...
}
And annotate your builder with JsonPOJOBuilder as :
#JsonPOJOBuilder(buildMethodName = "createVehicleDTO", withPrefix = "set")
public static class VehicleDTOBuilder{
...
}
According to the javadoc, JsonPOJOBuilder is :
used to configure details of a Builder class: instances of which are
used as Builders for deserialized POJO values, instead of POJOs being
instantiated using constructors or factory methods. Note that this
annotation is NOT used to define what is the Builder class for a POJO:
rather, this is determined by JsonDeserialize.builder() property of
JsonDeserialize.
I faced this error when I used Lombok's #Builder and #Data annotations together on a POJO class that is used for connecting to an API (either for consuming or for providing response)
I removed the #Builder annotation and then it is working fine
In my case:
InvalidDefinitionException: Cannot construct instance of com.vehicle.datatransferobject.VehicleDTO (no Creators, like default construct, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
for the above exception, I just write Default Constructor which instantiates class and solved the problem.
Default Constructor:
public VehicleDTO() {
super();
// TODO Auto-generated constructor stub
}
If you are using Lombok - the best thing is to add these annotations to your DTO:
#AllArgsConstructor
#RequiredArgsConstructor
#Data
#Builder (optional)
In addition to davidxxx`s answer. I used Lombok. And in my case it looked like this:
#Data
#JsonDeserialize(builder = SomeClass.SomeClassBuilder.class)
#Builder(builderClassName = "SomeClassBuilder")
public class SomeClass {
// ...
#JsonPOJOBuilder(withPrefix = "")
public static class SomeClassBuilder {
}
}

Json custom deserializer not called in Websphere

I have simple class and field id is annotated with custom deserializer.
public class TestRequest implements Serializable {
#NotNull
#Pattern(regexp = "^[a-zA-Z0-9=+]*$")
#JsonDeserialize(using = StringDeserializer.class)
#JsonProperty
private String id;
//getter
//setter
}
and the custom deserializer class :
public class StringDeserializer extends JsonDeserializer<String> {
#Override
public String deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) {
Iterator<String> iterator = jsonParser.readValuesAs(String.class);
String id = iterator.next();
return id + "0000";
}
}
When i test with with Jersey REST test, the deserilizer is called and works as expected. But with websphere it does not called. Any idea why its not called.
I am using jaxrs 1.1
You may need to add the #Provider annotation to your StringDeserializer class, otherwise the JAX-RS runtime will not recognize the class as a provdier.
Even though your class extends JsonDeserializer<String>, which itself is probably annotated with #Provider, the JAX-RS runtime will not scan libraries for annotations, as doing negatively impacts performance.
I made it working in Websphere by moving the annotation #JsonDeserialize(using = StringDeserializer.class) to setter method of the class
public class TestRequest implements Serializable {
#NotNull
#Pattern(regexp = "^[a-zA-Z0-9=+]*$")
#JsonProperty
private String id;
#JsonDeserialize(using = StringDeserializer.class)
public setId(String id){
this.id=id;
}
//getter
//setter
}

Morphia: inheritance not handled properly?

I have a class that implements an interface. Why are the arraylist contents not stored in the database? Here is some code to illustrate the problem.
The class
#Entity
public class MyClass implements MyInterface {
#Id
#Indexed
public String id;
public String someField;
public MyClass(String id, String someField){
this.id = id;
this.someField = someField;
}
}
The interface
public interface MyInterface {
#Embedded
public List<String> mylist = new ArrayList<String>();
}
Test code
#Test
public void test() {
testInheritance();
}
public void testInheritance() {
MyClass myClass = new MyClass("test", "someField");
myClass.myList.add("wow");
MyClassDao dao = new MyClassDao();
dao.save(myClass);
}
public class MyClassDao extends BasicDAO<MyClass, ObjectId> {
public MyClassDao() {
super(MyClass.class, MorphiaManager.getMongoClient(), MorphiaManager.getMorphia(), MorphiaManager.getDB().getName());
}
}
Result in DB
{
"_id" : "test",
"className" : "gr.iti.mklab.simmo.util.MyClass",
"someField" : "someField"
}
Interfaces can only declare method signatures and constants (static final variables). What you want to use is an abstract base class from which you inherit.
Additional observations from your code:
The id should be ob the type ObjectId and is automatically indexed, you don't need the #Indexed
Attributes should be private or protected and you need to provide getters and setters for them
You need a default no-arg constructor in your entity class

How to edit a Set<? extends EntityProxy> with GWT Editor framework?

for sake of simplicity:
public class Person
{
String name;
Set<Address> addresses;
}
public class Address
{
String city;
String street;
}
with and matching
public interface PersonProxy extends EntityProxy
{
public String getName();
public Set<AdressProxy> getAddresses();
}
and
public interface AdressProxy extends EntityProxy
{
public String getCity();
public String getStreet();
}
I got UiBuinder classes to edit AddressProxy
and it clear to me how to use ListEditor in case if I got List but data is Set in the Person class
how do I use Editor Framework to edit them?
Or may be how do I convert Set to List when it becomes PersonProxy?
I did an attempt to put a kind of adapter Editor class that would implement
LeafValueEditor<Set<AddressProxy>>
and then inside of the LeafValueEditor.setValue() move to a List and start a new driver.edit() on a separate Editor hierarchy that takes care of List editing but with now luck.
You should create a CompositeEditor<Set<AddressProxy>, AddressProxy, AddressEditor>, similar to a ListEditor but handling a Set instead of a List.
I suppose you could somehow delegate to a ListEditor though I'm really not sure.
I've done it with Points and Routes (one Route contains N Points):
Route (Composite):
#UiField
TextBox name;
#Ignore
#UiField
FlexTable listPoints;
PointsEditor pointsEditor = new PointsEditor();
....
pointsEditor.add(String id);
PointsEditor:
public class PointsEditor implements HasRequestContext<List<PointProxy>>, ValueAwareEditor<List<PointProxy>> {
List<PointProxy> points = new ArrayList<PointProxy>();
public void add(String id) {
PointProxy point = ctx.create(PointProxy.class);
point.setId(id);
points.add(point);
}
Route (server side):
#Embedded
private List<Point> points = new ArrayList<Point>();
RouteProxy
public interface RouteProxy extends EntityProxy {
abstract List<PointProxy> getPoints();
abstract void setPoints(List<PointProxy> points);
PointProxy
public interface PointProxy extends ValueProxy {
...
}