Java Class getGenericInterfaces() Method

The getField() method of java Class class returns the Types as an array of the type Type representing the interfaces directly implemented by the class or interface.

Syntax

Parameter

Returns

An array.

Throws

GenericSignatureFormatError, TypeNotPresentException MalformedParameterizedTypeException

Example 1

//import statements
  
import java.lang.reflect.*;

public class ClassgetGenericInterfacesExample1 {

   public static void main(String []args) {         

      ClassgetGenericInterfacesExample1 obj = new ClassgetGenericInterfacesExample1();
      Class cls = obj.getClass();

      Type[] tp = cls.getGenericInterfaces();
      if(tp.length != 0) {
         for(Type i : tp) {
            System.out.println(i.toString());  //converting I to string
         }
      } else {
         System.out.println("No interfaces impleamented...");  //print statement
      }
   }
}

Test it Now

Output:

No interfaces impleamented...

Example 2

//import statements
  
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.math.BigInteger;

public class ClassgetGenericInterfacesExample2 {

    public static void main(String... args) {
        Class<SampleClass> cls = SampleClass.class;
        Type[] gentp = cls.getGenericInterfaces();
        for (Type gen : gentp) {
            System.out.println(gentp);
            Type(gen);
        }
    }

      private static void Type(Type tpp) {
        if (tpp instanceof Class) {
            System.out.println("type is Class");
            System.out.println("class name: " + ((Class) tpp).getSimpleName());
        } else if (tpp instanceof ParameterizedType) {
            System.out.println("type is ParameterizedType");
            Type[] a = ((ParameterizedType) tpp).getActualTypeArguments();
            System.out.println("printing each one of ActualTypeArguments:");
            System.out.println("----");
            for (Type type1 : a) {
                Type(type1);
            }
            System.out.println("----");
        } else if (tpp instanceof TypeVariable) {
            System.out.println("type is TypeVariable");
            String typeVariableName = ((TypeVariable) tpp).getName();
            System.out.println("typeVariableName: " + typeVariableName);

        } else if (tpp instanceof GenericArrayType) {
            System.out.println("type is GenericArrayType");
            Type genericComponentType =
                    ((GenericArrayType) tpp).getGenericComponentType();
            Type(genericComponentType);
        }
    }

    private static class SampleClass implements Interface1<String, BigInteger> {}

    private static interface Interface1<T, R> {}
}

Test it Now

Output:

[Ljava.lang.reflect.Type;@7852e922
type is ParameterizedType
printing each one of ActualTypeArguments:
----
type is Class
class name: String
type is Class
class name: BigInteger
----

Next TopicJava Class

← prev next →