package com.nisum.java9Features.FactoryMethodsForUnmodifiableCollections; import java.sql.*; import java.util.*; import static java.util.Map.entry; public class UnmodifiableMap { public static void main(String[] args) { Map<String,String> map=Map.of("A","Apple","B","Banana","C","Cat","D","Dog"); System.out.println(map); /* Map<String,String> map1=Map.of("A","Apple","A","Banana","C","Cat","D","Dog"); System.out.println(map1); // IllegalArgumentException*/ /*Map<String,String> map2=Map.of("A",null,"B","Banana"); // NullPointerException System.out.println(map2);*/ Map.Entry<String,String> e1= entry("A","Apple"); Map.Entry<String,String> e2= entry("B","Banana"); Map.Entry<String,String> e3= entry("C","Cat"); Map<String,String> m=Map.ofEntries(e1,e2,e3); System.out.println(m); /* Map<String,String> map3=Map.ofEntries(entry(null,"Apple"),entry("B","Banana")); // NullPointerException System.out.println(map3);*/ /* Map<String,String> map4=Map.ofEntries(entry("A","Apple"),entry("B","Banana")); map4.put("C","Cat"); // UnsupportedOperationException map4.remove("A");//UnsupportedOperationException*/ } }