Dart using getter method to get private field value from class - dart

in this below class I have a private constructor with getter, unfortunately, I cant use this getter as userDao from outside of class, I get this error:
Instance member 'userDao' can't be accessed using static access.
class MydbModel {
UserDao _userDao;
MydbModel._(this._userDao);
static Future<MydbModel> create() async => MydbModel._(await fn());
static fn() {
MyDatabase myDatabase = MyDatabase();
myDatabase.initialDatabase();
return myDatabase.getUserDao();
}
UserDao get userDao=>_userDao;
}
for example:
final UserDao userDao = MydbModel.userDao;
this implementation means i use await on this constructor without create new instance from that to use and define this codes:
MyDatabase myDatabase = MyDatabase();
myDatabase.initialDatabase();
return myDatabase.getUserDao();
for example:
class MyDatabase {
AppDatabase db;
UserDao userDao;
Future<void> initialDatabase() async {
db = await $FloorAppDatabase.databaseBuilder('flutter_database.db').build();
}
UserDao getUserDao() {
return db.userDao;
}
}

final UserDao userDao = MydbModel.userDao;
You're trying to access an instance getter through the class. Either your getter and the private member need to be static or your need to construct an instance of MydbModel first.

Related

How do I mock an OAuth2Authentication Object in Spring Test

I would like to test my rest controller in spring. In my the service, a user requires to pass an authentication token. I use a token utils class that decodes the token and get an organization id. I then use the id for several processes. How do I do a mock of this in Spring? I have followed this documentation but am getting a 404 on running the test.
TodoController
#RequestMapping("todos")
class TodoController {
#Autowired
lateinit var todoService: TodoService
#Autowired
lateinit var tokenUtils: TokenUtils
#GetMapping
fun getAllTodos(authentication: OAuth2Authentication): ResponseEntity<List<Todo>> {
tokenUtils.init(authentication);
val organizationId = tokenUtils.organizationId
return ResponseEntity.ok(todoService.findAll(organizationId))
}```
I am a bit new to spring tests and will appreciate any help accorded
First you need to create a mock Authentication class that implements Authentication interface. Most of following code is auto generated. Override any method you you need (in this case, I only override getPrincipal method).
import java.util.Collection;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
public class MockPrincipal implements Authentication {
public MockPrincipal() {}
#Override
public String getName() {
// TODO Auto-generated method stub
return null;
}
#Override
public Collection<? extends GrantedAuthority> getAuthorities() {
// TODO Auto-generated method stub
return null;
}
#Override
public Object getCredentials() {
// TODO Auto-generated method stub
return null;
}
#Override
public Object getDetails() {
// TODO Auto-generated method stub
return null;
}
#Override
public Object getPrincipal() {
// TODO Auto-generated method stub
return "mock user";
}
#Override
public boolean isAuthenticated() {
// TODO Auto-generated method stub
return false;
}
#Override
public void setAuthenticated(boolean isAuthenticated) throws IllegalArgumentException {
// TODO Auto-generated method stub
}
}
After that you can mock up an OAuth2Authentication object like this:
MockPrincipal mockUser = new MockPrincipal();
OAuth2Authentication mockOAuth2Object = new OAuth2Authentication(null, mockUser);

Injecting HttpService into a Mule 4 Custom Configuration Properties Provider

I'm working on making a custom properties provider to load the contents of a Spring cloud config server at startup. I need to make a single call at the initialization of the provider to fetch these properties, and would like to use the Mule HttpService in order to make the http client for this call, instead of creating my own. Unfortunately, whenever I try this, it seems the HttpService hasn't been created yet and so throws an NPE once it's referenced.
CustomConfigurationPropertiesProviderFactory.java
public class CustomConfigurationPropertiesProviderFactory implements ConfigurationPropertiesProviderFactory {
public static final String EXTENSION_NAMESPACE = "custom-properties";
public static final String CONFIGURATION_PROPERTIES_ELEMENT = "config";
public static final ComponentIdentifier CUSTOM_CONFIGURATION_PROPERTIES =
builder().namespace(EXTENSION_NAMESPACE).name(CONFIGURATION_PROPERTIES_ELEMENT).build();
#Inject
HttpService httpService;
#Override
public ComponentIdentifier getSupportedComponentIdentifier() {
return CUSTOM_CONFIGURATION_PROPERTIES;
}
#Override
public ConfigurationPropertiesProvider createProvider(ConfigurationParameters parameters,
ResourceProvider externalResourceProvider) {
String url = parameters.getStringParameter("url");
return new CustomConfigurationPropertiesProvider(url, httpService);
}
}
CustomConfigurationPropertiesProvider.java
public class CustomConfigurationPropertiesProvider implements ConfigurationPropertiesProvider {
private final static String PREFIX = "custom::";
private Properties properties = null;
public CustomConfigurationPropertiesProvider(String url, HttpService httpService) {
HttpClientConfiguration.Builder builder = new HttpClientConfiguration.Builder();
builder.setName("customProperties");
HttpClient client = httpService.getClientFactory().create(builder.build()); //NPE here
client.start();
// proceed to create and execute request, then load into properties
}
#Override
public Optional<ConfigurationProperty> getConfigurationProperty(String configurationAttributeKey) {
if (configurationAttributeKey.startsWith(PREFIX)) {
String effectiveKey = configurationAttributeKey.substring(PREFIX.length());
if (properties != null && !properties.isEmpty()) {
return Optional.of(new ConfigurationProperty() {
#Override
public Object getSource() {...}
#Override
public Object getRawValue() { return properties.getProperty(effectiveKey); }
#Override
public String getKey() { return effectiveKey; }
});
}
}
return Optional.empty();
}
}
What do I need to change to properly inject this service?
I've been following the advice from these two bits of documentation, for reference:
https://docs.mulesoft.com/mule-runtime/4.2/custom-configuration-properties-provider
https://docs.mulesoft.com/mule-sdk/1.1/mule-service-injection

How to inject a bean into custom argument resolver?

Hello i use spring boot 1.3.2 version. I have a custom argument resolver which's name is ActiveCustomerArgumentResolver. Everything is great, resolveArgument method works fine but i can't initialize my service component which is of my custom arg. resolver. Is there a problem with lifecycle process? Here is my code:
import org.springframework.beans.factory.annotation.Autowired;
//other import statements
public class ActiveCustomerArgumentResolver implements HandlerMethodArgumentResolver {
#Autowired
private CustomerService customerService;
#Override
public boolean supportsParameter(MethodParameter parameter) {
if (parameter.hasParameterAnnotation(ActiveCustomer.class) && parameter.getParameterType().equals(Customer.class))
return true;
else
return false;
}
#Override
public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
Principal userPrincipal = webRequest.getUserPrincipal();
if (userPrincipal != null) {
Long customerId = Long.parseLong(userPrincipal.getName());
return customerService.getCustomerById(customerId).orNull(); //customerService is still NULL here, it keeps me getting NullPointerEx.
} else {
throw new IllegalArgumentException("No user principal is associated with the current request, yet parameter is annotated with #ActiveUser");
}
}
}
Let the Spring create the resolver for you by making it a Component:
#Component
public class ActiveCustomerArgumentResolver implements HandlerMethodArgumentResolver {...}
Then inject the resolver into your WebConfig instead of simply using the new, like following:
#EnableWebMvc
#Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
#Autowired private ActiveCustomerArgumentResolver activeCustomerArgumentResolver;
#Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
argumentResolvers.add(activeCustomerArgumentResolver);
}
}
This is how i've solved the problem, not a generic one but helps me a lot:
#Configuration
#EnableAutoConfiguration
#ComponentScan
public class Application extends WebMvcConfigurerAdapter {
private static final Logger logger = LoggerFactory.getLogger(Application.class);
#Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
argumentResolvers.add(activeCustomerArgumentResolver());
}
#Bean
public ActiveCustomerArgumentResolver activeCustomerArgumentResolver() {
return new ActiveCustomerArgumentResolver();
}
}

Jersey #Context scope

I have a hard time understanding the injection mechanism of Jersey. The JAX-RS Specification (http://jsr311.java.net/nonav/releases/1.1/spec/spec3.html#x3-520005) states that injection via #Context is possible in Application subclasses, root resource classes and providers.
I now have a class that is instantiated at startup and has a method which is called on every request. Inside the method I need access to the current UriInfo object. The problem is, that this method is not called from my code. So I can't pass UriInfo directly to the method.
I actually want to do something like this:
public class MyClass implements ThirdPartyInterface {
// not possible because class is no Application subclass, root resource class or provider
#Context
private UriInfo uriInfo;
public void methodCallebByThirdPartyCode() {
Uri requestUri = uriInfo.getRequestUri();
// do something
}
}
I tried this. Obviously with no success:
public class MyClass implements ThirdPartyInterface {
private UriInfo uriInfo;
public MyClass(UriInfo uriInfo) {
this.uriInfo = uriInfo;
}
public void methodCallebByThirdPartyCode() {
Uri requestUri = uriInfo.getRequestUri();
// do something
}
}
#Provider
#Produces(MediaType.WILDCARD)
public class MyBodyWriter implements MessageBodyWriter<MyView> {
#Context
private UriInfo uriInfo;
private MyClass myClass;
private ThirdPartyClass thirdPartyClass;
public MyBodyWriter() {
// uriInfo is null at this time :(
myClass = new MyClass(uriInfo);
thirdPartyClass = new ThirdPartyClass();
thirdPartyClass.register(myClass);
}
public void writeTo(final MyView view, final Class<?> type, /* and so on */) throws IOException, WebApplicationException {
// execute() calls MyClass#methodCallebByThirdPartyCode()
thirdPartyClass.execute();
}
}
The only workaround I can think of is this. I don't think it's very clean:
public class MyClass implements ThirdPartyInterface {
private UriInfo uriInfo;
public void setUriInfo(final UriInfo uriInfo) {
this.uriInfo = uriInfo;
}
public void methodCallebByThirdPartyCode() {
Uri requestUri = uriInfo.getRequestUri();
// do something
}
}
#Provider
#Produces(MediaType.WILDCARD)
public class MyBodyWriter implements MessageBodyWriter<MyView> {
#Context
private UriInfo uriInfo;
private MyClass myClass;
private ThirdPartyClass thirdPartyClass;
public MyBodyWriter() {
myClass = new MyClass();
thirdPartyClass = new ThirdPartyClass();
thirdPartyClass.register(myClass);
}
public void writeTo(final MyView view, final Class<?> type, /* and so on */) throws IOException, WebApplicationException {
myClass.setUriInfo(uriInfo);
// execute() calls MyClass#methodCallebByThirdPartyCode()
thirdPartyClass.execute();
myClass.setUriInfo(null);
}
}
I hope there is a better solution, but maybe I'm completely on the wrong track.
Thanks!
Late answer, but a good question ... so lets go:
You can use a org.glassfish.hk2.api.Factory and javax.inject.Provider for injections. I don't know since which version this is available, so maybe you have to upgrade your jersery version. For the following samples i used jersey 2.12.
First you have to implement and register/bind a Factory for your MyClass:
MyClassFactory:
import javax.inject.Inject;
import javax.ws.rs.core.UriInfo;
import org.glassfish.hk2.api.Factory;
// ...
public class MyClassFactory implements Factory<MyClass> {
private final UriInfo uriInfo;
// we will bind MyClassFactory per lookup later, so
// the constructor will be called everytime we need the factory
// meaning, uriInfo is also per lookup
#Inject
public MyClassFactory(final UriInfo uriInfo) {
this.uriInfo = uriInfo;
}
#Override
public MyClass provide() {
return new MyClass(uriInfo)
}
#Override
public void dispose(UriInfo uriInfo) {
// ignore
}
}
Registration via ResourceConfig:
import org.glassfish.hk2.api.PerLookup;
import org.glassfish.hk2.utilities.binding.AbstractBinder;
import org.glassfish.jersey.server.ResourceConfig;
// ...
public class MyResourceConfig extends ResourceConfig {
public MyResourceConfig() {
register(new AbstractBinder() {
#Override
protected void configure() {
bindFactory(MyClassFactory.class).to(MyClass.class).in(PerLookup.class);
// ... bind additional factories here
}
});
// ...
}
}
Now you are able to inject MyClass per lookup to providers, resources etc.
But Attention: Afaig there are two approaches and only one will work as eventually aspected for providers ...
import javax.inject.Inject;
import javax.ws.rs.Produces;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
// ...
#Provider
#Produces("application/foo-bar")
public class MyBodyWriter implements MessageBodyWriter<MyView> {
// first approache - don't do it!
// will only injected once, cause MyBodyWriter is only instantiated once
#Inject
private MyClass myClass;
// second approache - works fine!
private final javax.inject.Provider<MyClass> provider;
// MyBodyWriter instantiate once
// get an inject provider here
#Inject
public MyBodyWriter(javax.inject.Provider<MyClass> myClassProvider) {
this.provider = myClassProvider;
}
#Override
public boolean isWriteable(Class<?> t, Type g, Annotation[] a, MediaType m) {
return t == MyView.class;
}
#Override
public long getSize(MyView t, Class<?> c, Type g, Annotation[] a, MediaType m) {
// deprecated by JAX-RS 2.0 and ignored by Jersey runtime
return 0;
}
#Override
public void writeTo(MyView v, Class<?> c, Type t, Annotation[] a, MediaType m, MultivaluedMap<String, Object> s, OutputStream o) throws IOException, WebApplicationException {
// attention: its not per lookup !!!
MyClass myClassDirectInjected = myClass;
System.out.println(myClassDirectInjected); // same instance everytime
// but this is ;)
MyClass myClassFromProvider = provider.get();
System.out.println(myClassFromProvider); // it's a new instance everytime
// ...
}
}
Hope this was somehow helpfull.

How to use Ninject to create instances in child classes?

I am learning how to use nInject for a new application I am developing, and I have created the following sample code that can be copied/pasted into a simple console app. It successfully returns an instance of IFoo, but I have a question about it.
How would I modify the code to have the FooManager class create an instance of the Foo object without doing a 'new'. Does the kernal have to be injected as well? But if the kernal is injected and I change the line to read var foo = _kernel.Get<IFoo>(), isn't that introducing a service locator anti-pattern?
namespace IOCTest
{
class Program
{
static void Main(string[] args)
{
using (IKernel kernel = new StandardKernel(new StandardModule()))
{
// do something with the kernal
var mgr = kernel.Get<IFooManager>();
var foo = mgr.GetById(1);
}
}
}
public class StandardModule : Ninject.Modules.NinjectModule
{
public override void Load()
{
Bind<IDatabase>()
.To<Database>()
.InTransientScope();
Bind<IFooManager>()
.To<FooManager>()
.InTransientScope();
}
}
//******************************************************
public interface IDatabase
{
object[] GetScalar(int id);
}
public class Database : IDatabase
{
public object[] GetScalar(int id)
{
return new object[] { "RowName" };
}
}
//******************************************************
public interface IFooManager
{
IFoo GetById(int id);
}
public class FooManager : IFooManager
{
private IDatabase _db;
public FooManager(IDatabase db) { _db = db; }
public IFoo GetById(int id)
{
var results = _db.GetScalar(id);
var foo = new Foo(); // <-- HOW DO I ELIMINATE THIS DEPENDENCY?
foo.Name = results[0].ToString();
return foo;
}
}
//******************************************************
public interface IFoo
{
string Name { get; set; }
}
public class Foo : IFoo
{
public string Name { get; set; }
}
//******************************************************
}
First you have to think about the purpose of Foo. Is this some kind of a datacontainer or some service?
In the first case your code is perfect like it is. Datacontainers have no dependencies and shouldn't be created by the IoC container.
In the second case read about Ninject.Extensions.Factory.
http://www.planetgeek.ch/2011/12/31/ninject-extensions-factory-introduction/
https://github.com/ninject/ninject.extensions.factory/wiki
There are a couple ways to eliminate that dependency. You could do the same thing you did with the Database dependency and use constructor injection. You could do property injection (https://github.com/ninject/ninject/wiki/Injection-Patterns). Another way, and perhaps what you are looking for, would be service location. To do that you can update your FooManager ctor to require an IKernel. This will be resolved automatically and you can then use the kernel that is passed in to get Foo.
public class FooManager : IFooManager
{
private IDatabase _db;
private IKernel _kernel;
public FooManager(IDatabase db, IKernel kernel) { _db = db; _kernel = kernel;}
public IFoo GetById(int id)
{
var results = _db.GetScalar(id);
// var foo = new Foo(); // <-- HOW DO I ELIMINATE THIS DEPENDENCY?
var foo = kernel.Get<IFoo>(); // Like this perhaps
foo.Name = results[0].ToString();
return foo;
}
}

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