Testing requireNonNull(T obj, String message) from Objects class - Java Object Oriented Design

Java examples for Object Oriented Design:Objects Utility

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Description

Testing requireNonNull(T obj, String message) from Objects class

Demo Code

import java.util.Objects;
import java.util.function.Supplier;

public class Main {
  public static void main(String[] args) {
    // Testing requireNonNull(T obj, String message)
    try {/*w ww. j a v a  2  s  .c  o m*/
      printName("test");
      printName(null);
    } catch (NullPointerException e) {
      System.out.println(e.getMessage());
    }

    // requireNonNull(T obj, Supplier<String> messageSupplier)
    try {
      Supplier<String> messageSupplier = () -> "Name is required. ";
      printNameWithSuplier("aaa", messageSupplier);
      printNameWithSuplier(null, messageSupplier);
    } catch (NullPointerException e) {
      System.out.println(e.getMessage());
    }
  }
  public static void printName(String name) {
    // Test name for not null. Generate a NullPointerException if it is null.
    Objects.requireNonNull(name, "Name is required.");

    // Print the name if the above statement dod not throw an exception
    System.out.println("Name is " + name);
  }

  public static void printNameWithSuplier(String name,Supplier<String> messageSupplier) {
    // Test name for not null. Generate a NullPointerException if it is null.
    Objects.requireNonNull(name, messageSupplier);
    System.out.println("Name is " + name);
  }

}

Result


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