vavr add nested validations with validations combine - java

I have an input object as
class Person {
private String name;
private String email;
private String phone;
private Address address;
public static class Address {
private String city;
private String pincode;
private String street;
private AddrDetails details;
public static class AddrDetails {
private String state;
private String country;
}
}
}
I am using vavr Validations to validate the input
public static Validation<Seq<ConstraintViolation>, PersonDetailsModel> validatePerson(PersonDetailsRequest request) {
Validation
.combine(
validateName("name", request.getName()),
validateEmail("email", request.getEmail()),
validatePhone("phone", request.getPhone()),
validateAddress(request.getAddress())
).ap((name, email, phone, address) -> new PersonDetailsModel(name, email, phone, address);
}
public static Validation<Seq<ConstraintViolation>, Person.Address> validateAddress(
Person.Address request) {
return Validation
.combine(..
).ap((..) -> new Person.Address(..);
}
In the second function, it returns Seq of ConstraintViolation while validatePerson expects only ConstraintViolation which is why it is failing although I have to add one more level of nesting of validations for AddrDetails. How to handle nested objects validations with this approach.
I am not sure about how shall I go ahead?

In our project we call .mapError(Util::flattenErrors) after .ap. I have the feeling that there is a better way, but this at least solves the nesting.
The method in the Util class looks like this :
public static Seq<ConstraintViolation> flattenErrors(final Seq<Seq<ConstraintViolation>> nested) {
return nested
.flatMap(Function.identity())
.distinct(); // duplicate removal
}

Related

Jackson: remove some values from json and keep some null values

I have a model like this:
public class Employee {
#JsonProperty("emplyee_id")
private Integer id;
#JsonProperty("emplyee_first_name")
private String firstName;
#JsonProperty("emplyee_last_name")
private String lastName;
#JsonProperty("emplyee_address")
private String address;
#JsonProperty("emplyee_age")
private Byte age;
#JsonProperty("emplyee_level")
private Byte level;
//getters and setters
}
now I need to create two JSONs using this (only) model.
the first one must like this for example:
{
"employee_id":101,
"employee_first_name":"Alex",
"employee_last_name":"Light",
"employee_age":null,
"employee_address":null
}
and the second one must like this for example:
{
"employee_id":101,
"employee_level":5
}
by the way, I already tested #JsonIgnore and #JsonInclude(JsonInclude.Include.NON_NULL).
the problem of the first one (as much as I know) is, those fields can't be included in other JSONs (for example if level get this annotation, it won't be included in the second JSON)
and the problem of the second one is, null values can't be included in JSON.
so can I keep null values and prevent some other property to be included in JSON without creating extra models? if the answer is yes, so how can I do it? if it's not I really appreciate if anyone gives me the best solution for this state.
thanks very much.
it could be useful for you using #JsonView annotation
public class Views {
public static class Public {
}
public static class Base {
}
}
public class Employee {
#JsonProperty("emplyee_id")
#JsonView({View.Public.class,View.Base.class})
private Integer id;
#JsonProperty("emplyee_first_name")
#JsonView(View.Public.class)
private String firstName;
#JsonProperty("emplyee_last_name")
#JsonView(View.Public.class)
private String lastName;
#JsonProperty("emplyee_address")
private String address;
#JsonProperty("emplyee_age")
private Byte age;
#JsonProperty("emplyee_level")
#JsonView(View.Base.class)
private Byte level;
//getters and setters
}
in your json response add #JsonView(Public/Base.class) it will return based on jsonview annotations
//requestmapping
#JsonView(View.Public.class)
public ResponseEntity<Employee> getEmployeeWithPublicView(){
//do something
}
response:
{
"employee_id":101,
"employee_first_name":"Alex",
"employee_last_name":"Light",
"employee_age":null,
"employee_address":null
}
for the second one
//requestmapping
#JsonView(View.Base.class)
public ResponseEntity<Employee> getEmployeeWithBaseView(){
//do something
}
response
{
"employee_id":101,
"employee_level":5
}

Gson - Read a value with two different keys

In my Android project I have two types of response where both response are identical except two keys.
Response 1
{"fullName":"William Sherlock Scott Holmes","address":"221B Baker Street, London, England, UK","downloads":642,"rating":3,"repos":["https://link1","https://link2","https://link3"]}
Response 2
{"name":"Sherlock","city":"London","downloads":642,"rating":3,"repos":["https://link1","https://link2","https://link3"]}
If you see the responses only two key names are changing fullName/name and address/city
I don't want to create one more pojo for other response. My question is: is it possible to use only one Pojo to read both responses?
public class AccountInfo {
private String name;
private String city;
//other objects
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
//other setters and getters
}
Any help will be appreciated...
You can annotate the members to accept values from two different json names using the #SerializedName annotation:
#SerializedName(value = "name", alternate = {"fullName"})
private String name;
#SerializedName(value = "city", alternate = {"address"})
private String city;
Either named element can then be placed into the members that are annotated like this.
UPDATED :
#SerializedName alternate names when deserializing is added in Version 2.4
Yes, you can totally use one POJO class for deserializing both responses. Your POJO class will contain keys from both responses.
public class Response {
private String name;
private String city;
private String fullName;
private String address;
private Integer downloads;
private Integer rating;
private List<String> repos ;
}
But when using the Response class, be careful that for first response, the name and city will be null, and for the second one, the address and fullname.
Yeah you can do that in a single POJO. Try this:
public class POJO {
#SerializedName("name")
public String name;
#SerializedName("city")
public String city;
#SerializedName("fullName")
public String fullName;
#SerializedName("address")
public String address;
#SerializedName("downloads")
public Integer downloads;
#SerializedName("rating")
public Integer rating;
#SerializedName("repos")
public List<String> repos = new ArrayList<String>();
}
While parsing you have to check values for null. For eg -
While Parsing Response 1: name and city variables will be null
While Parsing Response 2: fullname and address will be null
Note : Try checking values for null before using else you'll get nullpointerexception
Define all possible fields in your POJO Class like
public class AccountInfo {
private String name;
private String city;
private String fullname;
private String address;
}
While performing operation check for null in those feilds

Java trouble serializing a field of an object

I'm trying to learn about serialization and encountered the following problem:
I have an implementation of a customer that looks somewhat like this.
private static customerCount = 0;
private String customerID;
private String name;
private String street;
private String city;
private String postcode;
private String type;
I'm trying to serialize / deserialize an Arraylist
In the constructor, the ID will be created like this:
private Customer(...){
this.customerID = "ID" + customerCount;
customerCount++;
}
The serialization process works, however, all the IDs are set to ID0 when I deserialize.
Can anyone help resolve this problem?
Update: Alright, I just found out that static fields wont be serialized. How can I "model" the ID of a customer so I can serialize it? I need to have a unique value to create IDs for customers.
Here's a solution that combines the factory with the list that keeps track of customer count.
The customer class has a protected constructor, forcing you to build them through another means within the same package.
public class Customer implements Serializable {
private String customerID;
private String name;
private String street;
private String city;
private String postcode;
private String type;
protected Customer(String customerID,
String name,
String street,
String city,
String postcode,
String type) {
this.customerID = customerID;
this.name = name;
this.street = street;
this.city = city;
this.postcode = postcode;
this.type = type;
}
}
Now within the package, create a list wrapper like this:
public class CustomerList {
private int customerCount = 0;
private List<Customer> customers = new ArrayList<>();
public boolean addCustomer(String name,
String street,
String city,
String postcode,
String type) {
Customer customer = new Customer("ID" + customerCount++,
name,
street,
city,
postcode,
type);
return customers.add(customer);
}
}
This class then takes care of constructing the new customer, and provides a unique ID.
Edit: Just noticed that you now also have the upside of making the CustomerList class serializable as well. Then you can load it and still have an accurate customer count for adding additional uniquely ID-ed customers.
Usually, you would like to serialize only attributes and their values, not the logic from the class. Logic should happen before serialization or after deserialization.

ModelMapper mapping from multi flat object to hierarchy object

I have a situation, where I need to map multi objects (in a flat structure) into one object (an hierarchy object) in Java using ModelMapper.
For example,
class Person{
String name;
int age;
}
class Address{
int streetSumber;
String streetName;
String city;
}
class Phone{
String type;
String number;
}
What I want to get out from the model mapper is something like
class PersonDTO{
String name;
int age;
class AddressDTO{
int streetSumber;
String streetName;
String city;
}
class PhoneDTO{
String type;
String number;
}
}
Is there a way to simple achieve this?
Thanks
You must create a PersonWrapper
class PersonWrapper {
Person person;
Address address;
Phone phone;
}
and map PersonWrapper to PersonDTO, for example
PropertyMap<PersonWrapper, PersonDTO> orderMap = new PropertyMap<Order, OrderDTO>() {
protected void configure() {
map().setName(source.getPerson().getName());
....
}
};

Is there any way to avoid duplicating attributes in this code?

Hi i want to know if exist a way to avoid duplicate code in this code. Now i have an action class named CustomerAction this class handle the behaviour of the request (it's like a controller) and i have a CustomerPOJO with attributes like id, name, last_name etc. Now i have to add attributes to CustomerAction to handle the data submited from the form. Is there any way to bypass the action with my CustomerPOJO ?
public class CustomerAction {
private String nombre;
private String apellido;
private String dni;
private String fechaNac;
private String obraSocial;
private String nroAsociado;
private String plan;
private String password;
private String email;
private String telParticular;
private String telCelular;
private static final Log log = LogFactory
.getLog(CustomerAction.class);
public String execute() throws Exception {
if ("cancelar".equals(this.getAccion())) {
log.debug("Executing 'cancelar' action");
return "login";
}
if ("registro".equals(accion)) {
log.debug("Executing 'registro' action");
IReferenceDataBusinessDelegate ud = new ReferenceDataBusinessDelegate();
ud.signCustomer(this.getNombre(), this.getApellido(),
this.getDni(), this.getCorreo(), this.getContrasena());
return "login";
}
}
public class Customers implements java.io.Serializable {
private long id;
private String dni;
private String name;
private String lastName;
private String email;
private String password;
private String phone;
private String cellphone;
private Date birthDate;
private Date creationDate;
private Date lastAccessDate;
private byte active;
private Set<Profesionales> profesionaleses = new HashSet<Profesionales>(0);
private Set<Pacientes> pacienteses = new HashSet<Pacientes>(0);
public Customers() {
}
}
Yes, use ModelDriven, and use a Customers as the model.
http://struts.apache.org/2.x/docs/model-driven.html
You'll need to make sure the "modelDriven" interceptor is in your stack.
How/where to initialize the model depends on your particular usage scenario; you can do it in a getter as shown in the docs, in a prepare() method if you need to reload it from the DB, etc.
I'm not sure what you mean by "bypass the action."
Please note that the ad-hoc dispatch mechanism implemented here with the accion parameter duplicates functionality provided by Struts 2 using the method attribute of the action configuration. I don't recommend using ad-hoc dispatch mechanisms as it makes understand program flow more difficult than necessary.

Categories