a generic interface java with parameters code example
Example 1: generics Interface in java
/*We know that Java inheritance allows us to assign a variable A to another variable B if A is subclass of B. So we might think that any generic type of A can be assigned to generic type of B, but it’s not the case. Let’s see this with a simple program.
We are not allowed to assign MyClass<String> variable to MyClass<Object> variable because they are not related, in fact MyClass<T> parent is Object.*/
package com.journaldev.generics;
public class GenericsInheritance {
public static void main(String[] args) {
String str = "abc";
Object obj = new Object();
obj=str; // works because String is-a Object, inheritance in java
MyClass<String> myClass1 = new MyClass<String>();
MyClass<Object> myClass2 = new MyClass<Object>();
//myClass2=myClass1; // compilation error since MyClass<String> is not a MyClass<Object>
obj = myClass1; // MyClass<T> parent is Object
}
public static class MyClass<T>{}
}
Example 2: generics Interface in java
/*In similar way, we can create generic interfaces in java. We can also have multiple type parameters as in Map interface. Again we can provide parameterized value to a parameterized type also, for example new HashMap<String, List<String>>(); is valid.*/
package java.lang;
import java.util.*;
public interface Comparable<T> {
public int compareTo(T o);
}