I want to generate java class.
I create a template with velocity
#Repository
public class $className extends BaseRepository<$bean, $searchDto> {
#PersistenceContext
private EntityManager em;
#Autowired
public $className(EntityManager em) {
super($bean.class, em);
}
}
If I pass this value
className=UsersRepositoryImpl
bean=Users
searchDto=UsersSearch
I get
#Repository
public class UsersRepositoryImpl extends BaseRepository<Users, UsersSearch> {
#PersistenceContext
private EntityManager em;
#Autowired
public UsersRepositoryImpl(EntityManager em) {
super(class java.lang.String, em);
}
}
seem like a issue with $bean.class
tried "$bean.class" but get same issue
Edit
put {} around work
${bean}
You need to call
${bean}.class
which tells the velocity processor that ${bean} is the velocity variable and .class is just static text of the template. Othherwise he will interpret $bean.class as one expression, your $bean is a String and $bean.class is therefore printed using the toString method of the String's Class object.
Related
I have the following Repository:
public class TestRepository : WebCaller<Data>, ITestRepository
{
string connString = this.GetConnectionString();
.... some code here
}
In my Repository I can do Dependency Injection to the constructor without a problem.
In my abstract class WebCaller I need to get access to HttpContext somehow, I was reading that you can Inject IHttpContextAccessor to get access to the context, but because this is an Abstract class, that also lives outside the Web project, I can't have a constructor.
I was trying to do this:
public abstract class WebCaller<T> : WebRequest, IDisposable
{
//[Inject]
public ITestRepository TestRepo
{
get
{
return this.HttpContext.RequestServices.GetRequiredService<ITestRepository >();
}
}
..... more code here
}
Was trying to use Inject attribute but was reading that is no longer available, so should be other way to pass HttContext to the abstract class.
You can have a constructor on your abstract class. Just inject IHttpContextAccessor to it. Then any derived class will also take IHttpContextAccessor and pass it to its base constructor (your abstract class constructor). You can make the abstract class constructor protected.
Like:
public abstract class WebCaller<T> : WebRequest, IDisposable
{
protected WebCaller(IHttpContextAccessor contextAccessor)
{
}
}
public class TestRepository : WebCaller<Data>, ITestRepository
{
public TestRepository(IHttpContextAccessor contextAccessor) : base(contextAccessor)
{
}
string connString = this.GetConnectionString();
.... some code here
}
I have a Junit 5 non static parameterized test where I am using #MethodSource to get the test data.
The Method Source arguments are getting the data from other methods as below code. I made the #MethodSource non static by having a
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
The fullDomain parameter in the #MethodSource is derived from the method getFullDomain() in the registrationPage which is also non static . I #Autowired the RegistrationPage in the BaseTest and using it by extending in my Junit5SampleTest Class
When I run the test the fullDomain is returning null. Is there a way to fix this or can I use any others like #ArgumentSource to fix this.
I will need to get the Arguments.of("Successful Regisration", fullDomain) data from different classes and its methods.
Base Test:
public class BaseTest {
#Autowired
protected RegistrationPage registrationPage;
}
Test Class:
#TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class Junit5SampleTest extends BaseTest {
String fullDomain = registrationPage.getFullDomain();
Stream<Arguments> registrationInputParameters() {
return Stream.of(
Arguments.of("Successful Regisration", fullDomain)
}
#ParameterizedTest()
#MethodSource("registrationInputParameters")
public void junit5(String testName, String fullDomain){
System.out.println(testName);
open(fullDomain);
}
}
I'm new to OSGI framework and I'm trying to access the 'Derived' Class variable 'publicVariable' from another class 'Derived2' like "Derived.publicVariable" but publicVariable is always shows null. I really appreciate if someone can help me out with this.
Thanks
Manifest file - Derived2
Require-Bundle:com.xxxxxx.Derived1
Java code
abstract class Base {
protected Vector <String> supportedCommands = new Vector <String> ();
protected abstract void initialiseCommands();
}
class Derived extends Base {
private static Derived derivedPlugin = null;
public Derived()
{
derivedPlugin = this;
}
public static Derived getPlugin()
{
return derivedPlugin;
}
public String publicVariable = null;
protected void initialiseCommands()
{
publicVariable = "someData";
System.out.println("Derived" + publicVariable);
}
}
class Derived2 extends Base {
protected void initialiseCommands()
{
supportedCommands.add(Derived.getPlugin().publicVariable);
System.out.println("IMRSAUtilitiesPlugin" +supportedCommands);
}
Also referred below link, which is a similar issue but i'm not using any static variable, it is just a public variable.
how use Singleton object in different class loader....?
The code in the question will not compile. You are trying to access an instance field (publicVariable in class Derived) in a static way, i.e. Derived.publicVariable.
OSGi does not change the semantics of the Java language, and if you cannot even compile your code then OSGi will certainly not be able to run it.
I created a project to test the dependency injection offered by Google Guice in my Jax-rs resources, using Resteasy.
My intentions are:
Use multiple #ApplicationPath for the versions of my API. In each class annotated with #ApplicationPath I load a set of classes for the specific version.
Each resource have a #Inject (from Google Guice) in his constructor to inject some services.
I created two classes annotated with #ApplicationPath: ApplicationV1RS and ApplicationV2RS. In both I added the same resources classes (UserResource and HelloResource), only for my test.
My Module is configured like this:
public class HelloModule implements Module
{
public void configure(final Binder binder)
{
binder.bind(IGreeterService.class).to(GreeterService.class);
binder.bind(IUserService.class).to(UserService.class);
}
}
When I call http://localhost:9095/v1/hello/world or http://localhost:9095/v2/hello/world, I receive the same error:
java.lang.RuntimeException: RESTEASY003190: Could not find constructor
for class: org.jboss.resteasy.examples.guice.hello.HelloResource
Well, as I expected, this not works. The Google Guice is not "smart" to instantiate the resource classes using the construtor for me.
But I can't find a way to work. To be really honest, I'm really confuse about how the Google Guice, Jetty and Resteasy play with each other in this scenario.
If I abandon the idea of use #ApplicationPath, my resources work with Google Guice configuring my HelloModule like this:
public class HelloModule implements Module
{
public void configure(final Binder binder)
{
binder.bind(HelloResource.class);
binder.bind(IGreeterService.class).to(GreeterService.class);
binder.bind(UserResource.class);
binder.bind(IUserService.class).to(UserService.class);
}
}
But in this case, I'm passing the control to register my resources (HelloResource and UserResource) to Guice. It's not flexible for me, I can't setup my multiple #ApplicationPath.
So, what I'm missing or not understanding?
I created a project with the problemetic code. Is very easy to setup and test: https://github.com/dherik/resteasy-guice-hello/tree/so-question/README.md
Thanks!
When you have getClasses method in your Application then it tries to create instance for all the registered resources using the default constructor which is missing in our Resources class. One way is to create a default constructor and Inject the dependencies through setter Injection.
And then instead of overriding getClasses in ApplicationV1RS and ApplicationV2RS you override getSingletons. Since Resources can be Singleton.
Below are the changes that I made to make it work the way you want.
ApplicationV1RS.java
#ApplicationPath("v1")
public class ApplicationV1RS extends Application {
private Set<Object> singletons = new HashSet<Object>();
public ApplicationV1RS(#Context ServletContext servletContext) {
}
#Override
public Set<Object> getSingletons() {
Injector injector = Guice.createInjector(new HelloModule());
HelloResource helloResource = injector.getInstance(HelloResource.class);
UserResource userResource = injector.getInstance(UserResource.class);
singletons.add(helloResource);
singletons.add(userResource);
return singletons;
}
}
ApplicationV2RS.java
#ApplicationPath("v2")
public class ApplicationV2RS extends Application {
private Set<Object> singletons = new HashSet<Object>();
public ApplicationV2RS(#Context ServletContext servletContext) {
}
#Override
public Set<Object> getSingletons() {
Injector injector = Guice.createInjector(new HelloModule());
HelloResource helloResource = injector.getInstance(HelloResource.class);
UserResource userResource = injector.getInstance(UserResource.class);
singletons.add(helloResource);
singletons.add(userResource);
return singletons;
}
}
HelloResource.java
#Path("hello")
public class HelloResource {
#Inject
private IGreeterService greeter;
public HelloResource() {
}
#GET
#Path("{name}")
public String hello(#PathParam("name") final String name) {
return greeter.greet(name);
}
}
UserResource.java
#Path("user")
public class UserResource {
#Inject
private IUserService userService;
public UserResource() {
}
#GET
#Path("{name}")
public String hello(#PathParam("name") final String name) {
return userService.getUser(name);
}
}
Add #Singleton to your Service Classes.
Hope it helps.
I have also pushed the code to forked repo. check it out
i have a question regarding design patterns.
suppose i want to design pig killing factory
so the ways will be
1) catch pig
2)clean pig
3) kill pig
now since these pigs are supplied to me by a truck driver
now if want to design an application how should i proceed
what i have done is
public class killer{
private Pig pig ;
public void catchPig(){ //do something };
public void cleanPig(){ };
public void killPig(){};
}
now iam thing since i know that the steps will be called in catchPig--->cleanPig---->KillPig manner so i should have an abstract class containing these methods and an execute method calling all these 3 methods.
but i can not have instance of abstract class so i am confused how to implement this.
remenber i have to execute this process for all the pigs that comes in truck.
so my question is what design should i select and which design pattern is best to solve such problems .
I would suggest a different approach than what was suggested here before.
I would do something like this:
public abstract class Killer {
protected Pig pig;
protected abstract void catchPig();
protected abstract void cleanPig();
protected abstract void killPig();
public void executeKillPig {
catchPig();
cleanPig();
killPig();
}
}
Each kill will extend Killer class and will have to implement the abstract methods. The executeKillPig() is the same for every sub-class and will always be performed in the order you wanted catch->clean->kill. The abstract methods are protected because they're the inner implementation of the public executeKillPig.
This extends Avi's answer and addresses the comments.
The points of the code:
abstract base class to emphasize IS A relationships
Template pattern to ensure the steps are in the right order
Strategy Pattern - an abstract class is as much a interface (little "i") as much as a Interface (capital "I") is.
Extend the base and not use an interface.
No coupling of concrete classes. Coupling is not an issue of abstract vs interface but rather good design.
public abstract Animal {
public abstract bool Escape(){}
public abstract string SaySomething(){}
}
public Wabbit : Animal {
public override bool Escape() {//wabbit hopping frantically }
public override string SaySomething() { return #"What's Up Doc?"; }
}
public abstract class Killer {
protected Animal food;
protected abstract void Catch(){}
protected abstract void Kill(){}
protected abstract void Clean(){}
protected abstract string Lure(){}
// this method defines the process: the methods and the order of
// those calls. Exactly how to do each individual step is left up to sub classes.
// Even if you define a "PigKiller" interface we need this method
// ** in the base class ** to make sure all Killer's do it right.
// This method is the template (pattern) for subclasses.
protected void FeedTheFamily(Animal somethingTasty) {
food = somethingTasty;
Catch();
Kill();
Clean();
}
}
public class WabbitHunter : Killer {
protected override Catch() { //wabbit catching technique }
protected override Kill() { //wabbit killing technique }
protected override Clean() { //wabbit cleaning technique }
protected override Lure() { return "Come here you wascuhwy wabbit!"; }
}
// client code ********************
public class AHuntingWeWillGo {
Killer hunter;
Animal prey;
public AHuntingWeWillGo (Killer aHunter, Animal aAnimal) {
hunter = aHunter;
prey = aAnimal;
}
public void Hunt() {
if ( !prey.Escape() ) hunter.FeedTheFamily(prey)
}
}
public static void main () {
// look, ma! no coupling. Because we pass in our objects vice
// new them up inside the using classes
Killer ElmerFudd = new WabbitHunter();
Animal BugsBunny = new Wabbit();
AHuntingWeWillGo safari = new AHuntingWeWillGo( ElmerFudd, BugsBunny );
safari.Hunt();
}
The problem you are facing refer to part of OOP called polymorphism
Instead of abstract class i will be using a interface, the difference between interface an abstract class is that interface have only method descriptors, a abstract class can have also method with implementation.
public interface InterfaceOfPigKiller {
void catchPig();
void cleanPig();
void killPig();
}
In the abstract class we implement two of three available methods, because we assume that those operation are common for every future type that will inherit form our class.
public abstract class AbstractPigKiller implements InterfaceOfPigKiller{
private Ping pig;
public void catchPig() {
//the logic of catching pigs.
}
public void cleanPig() {
// the logic of pig cleaning.
}
}
Now we will create two new classes:
AnimalKiller - The person responsible for pig death.
AnimalSaver - The person responsible for pig release.
public class AnimalKiller extends AbstractPigKiller {
public void killPig() {
// The killing operation
}
}
public class AnimalSaver extends AbstractPigKiller {
public void killPing() {
// The operation that will make pig free
}
}
As we have our structure lets see how it will work.
First the method that will execute the sequence:
public void doTheRequiredOperation(InterfaceOfPigKiller killer) {
killer.catchPig();
killer.cleanPig();
killer.killPig();
}
As we see in the parameter we do not use class AnimalKiller or AnimalSever. Instead of that we have the interface. Thank to this operation we can operate on any class that implement used interface.
Example 1:
public void test() {
AnimalKiller aKiller = new AnimalKiller();// We create new instance of class AnimalKiller and assign to variable aKiller with is type of `AnimalKilleraKiller `
AnimalSaver aSaver = new AnimalSaver(); //
doTheRequiredOperation(aKiller);
doTheRequiredOperation(aSaver);
}
Example 2:
public void test() {
InterfaceOfPigKiller aKiller = new AnimalKiller();// We create new instance of class AnimalKiller and assign to variable aKiller with is type of `InterfaceOfPigKiller `
InterfaceOfPigKiller aSaver = new AnimalSaver(); //
doTheRequiredOperation(aKiller);
doTheRequiredOperation(aSaver);
}
The code example 1 and 2 are equally in scope of method doTheRequiredOperation. The difference is that in we assign once type to type and in the second we assign type to interface.
Conclusion
We can not create new object of abstract class or interface but we can assign object to interface or class type.