logo
down
shadow

How to correctly implement a generic interface in Java


How to correctly implement a generic interface in Java

By : Venkatesh Palagani
Date : October 25 2020, 07:10 AM
I think the issue was by ths following , Both Plugin and Product are examples of generic types. The fact that you you've used the T parameter in both places, means that you expect these both to receive the same generic type.
For example, if you specified string as the type for T (although this wouldn't meet your data constraint), your customer method would expect to receive an instance of Plugin.
code :


Share : facebook icon twitter icon
How to correctly create a bounded generic class that extends a generic interface in Java

How to correctly create a bounded generic class that extends a generic interface in Java


By : Fabio Bazacas Zetola
Date : March 29 2020, 07:55 AM
I hope this helps . Generics types are not inherited. To make it compiles:
code :
IMessage<? extends IBasicInput, ? extends IBasicOutput> message =
    new Type1Message<BasicInput1, BasicOutput1>();
IMessage<IBasicInput, IBasicOutput> message = new Type1Message<>();
Implement Interface with Generic Java

Implement Interface with Generic Java


By : maksm
Date : March 29 2020, 07:55 AM
should help you out I can't call string methods on element and argument. The UML diagram tells me that StartsWith class has a Generic TypeT>String. I read in an other post you need to implement it in this way . I would like to substitute Object for T in the method here public boolean predicate(Object element, Object argument) but the compiler throws at me thats not possible. , Change to
code :
public class StartsWith <T extends String> implements Intaf<T> {

    @Override
    public boolean pres(T element, T argument) {

        String firstLetterElement = element.substring(0,1);

        String firstLetterArgument = argument.substring(0,1);

        return firstLetterElement.equals(firstLetterArgument);
    }
}
Why can a Java generic class implement a method of a generic interface with Object parameter?

Why can a Java generic class implement a method of a generic interface with Object parameter?


By : Jairo Honorio
Date : March 29 2020, 07:55 AM
like below fixes the issue I have probably found the answer:
During the type erasure process, the Java compiler erases all type parameters and replaces each with its first bound if the type parameter is bounded, or Object if the type parameter is unbounded.
code :
public class Node<T> {

    private T data;
    private Node<T> next;

    public Node(T data, Node<T> next) {
        this.data = data;
        this.next = next;
    }

    public T getData() { return data; }
    // ...
}
public class Node {

    private Object data;
    private Node next;

    public Node(Object data, Node next) {
        this.data = data;
        this.next = next;
    }

    public Object getData() { return data; }
    // ...
}
public class Node<T extends Comparable<T>> {

    private T data;
    private Node<T> next;

    public Node(T data, Node<T> next) {
        this.data = data;
        this.next = next;
    }

    public T getData() { return data; }
    // ...
}
public class Node {

    private Comparable data;
    private Node next;

    public Node(Comparable data, Node next) {
        this.data = data;
        this.next = next;
    }

    public Comparable getData() { return data; }
    // ...
}
How to correctly implement generic interface method?

How to correctly implement generic interface method?


By : Maxum Jabrailadzze
Date : March 29 2020, 07:55 AM
With these it helps 1) You need to define the generic parameter on the level of your interface. Otherwise the T parameter is not known to the compiler:
code :
public interface IWorker<T> where T: SomeModel
{
    Template Get(List<T> someModels);
}
public abstract class SomeModel { ... }    

public class SomeModelA : SomeModel
{
    public string Name { get; set; }
}

public class SomeModelB : SomeModel
{
    public string Age { get; set; }
}
public class WorkerA : IWorker<SomeModelA>
{
    public Template Get(List<SomeModelA> someModels)
    {
        ProcessModels(someModels);
        return new Template(); // let's say it's based on the result of ProcessModels
    }

    private void ProcessModels(List<SomeModelA> models)
    {
        var x = models.First();
    }
}

public class WorkerB : IWorker<SomeModelB>
{
    public Template Get(List<SomeModelB> someModels)
    {
        ProcessModels(someModels);
        return new Template(); // let's say it's based on the result of ProcessModels
    }

    private void ProcessModels(List<SomeModelB> models)
    {
        var x = models.First();
    }
}
public Template Get<SomeModelA>(List<SomeModelA> someModels)
                      ^
                      |
                   remove this
public class WorkerA : IWorker<SomeModelA>
var worker = new WorkerA();
var itemsBasedOnModelA = worker.Get(new List<SomeModelA>());

var workerB = new WorkerB();
var itemsBasedOnModelB = worker.Get(new List<SomeModelB>());
                           ^
                           |
                    this should be [workerB]!
Implement generic interface with generic type in Java

Implement generic interface with generic type in Java


By : user2963279
Date : March 29 2020, 07:55 AM
Hope that helps You are re-defining the generic parameter on method accept(...). The mechanic is similar to hiding attributes through local variables with the same name.
The T on public void accept(ListResponse response) is not "coupled" to the T on public class ListPresenter implements Consumer>.
code :
public class ListPresenter<T> implements Consumer<ListResponse<T>> {
    ...
    public void accept(ListResponse<T> response) {
        ...
    }
    ...
}
Related Posts Related Posts :
  • Is O(N!*N) an acceptable big oh complexity class or do I remove the constant and just say O(N!)?
  • Java File URI error?
  • Using an interface as a constructor parameter in Java?
  • Add additional path to exec-maven-plugin
  • Natural Language parsing of an appointment?
  • Java: How to tell which fontconfig file my system is currently using?
  • How to create notification icon badge on Android apps (like iPhone)
  • Interfaces with hibernate annotations
  • Getting ConnectionTimeoutException with the host did not accept the connection within timeout
  • How to get all property names of a Groovy class?
  • Java Netscape LDAP Remove One Attribute
  • A simple two column layout with Swing
  • Making a Linked list using Generics
  • how to handle result set data
  • Cloning java ArrayList and preventing it from modifications
  • Java How to call method of grand parents?
  • running jython bytecode using java
  • get content from website with utf8 format
  • Sendgrid v3: "Substitutions may not be used with dynamic templating"
  • Application freezes when running method
  • Maven versioning using git branches
  • does a Java getter incur a performance penalty
  • Open Source Implementation of Checkers
  • How can I make a resizable array in Java?
  • Change size of ImageIcon in a JRadioButton
  • Java memory mapped files and swap
  • JAXB Annotated class - setting of a variable which is not an element
  • JSF don't find component in view root with the form id
  • Using Mockito, how do I match against the key-value pair of a map?
  • How do I run my application as superuser from Eclipse?
  • Spring-Security: Call method after authentication
  • How can I add a password to this JDBC:ODBC connection string that is trying to connect to an MS Access database
  • java.sql.SQLException: database locked
  • Json Jackson deserialization without inner classes
  • Error starting modern compiler
  • Generate a random number in interval [0,360) which is divisible by number 15
  • Rotate watermark text at 45 degree angle across the center Apache PDFBox
  • Generate Random number in a range with no repeatation
  • Starting HBASE, java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
  • Using getter and setter methods inside a class in my main class
  • java: <identifier> expected with ArrayList
  • Java Reflection, java.lang.IllegalAccessException Error
  • Looking for a lightweight java-compatible in-memory key-value store
  • What is your development checklist for Java low-latency application?
  • Read a line in java and then tokenize it
  • How to format a date using Apache Derby?
  • Explicitly multiplying values as longs
  • Starting out NLP - Python + large data set
  • Software Testing Tools - for java
  • JDBC transaction dead-lock: solution required?
  • Measuring the time to create and destroy a simple object
  • Javadoc error: "option --boot-class-path not allowed with target 11"
  • How can I store values in a hashmap with <String, List<Integer>>
  • JDBC ODBC.. (Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException)
  • Unable to detect Capture Device (webcam) through JMF
  • Audio fingerprinting library (java)
  • Help matching fields between two classes
  • Access variables between nested JSP tags
  • AES Encryption Java Invalid Key length
  • How to initiate chatting between two clients and two clients only, using applets and servlets?
  • shadow
    Privacy Policy - Terms - Contact Us © 35dp-dentalpractice.co.uk