merge maps first example

core-java-collections/src/main/java/com/baeldung/map/java_8/MergeMaps.java

@@ -0,0 +1,41 @@
+package com.baeldung.map.java_8;
+
+import com.baeldung.sort.Employee;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class MergeMaps {
+
+    private static Map<String, Employee> map1 = new HashMap<>();
+    private static Map<String, Employee> map2 = new HashMap<>();
+
+    public static void main(String[] args) {
+
+        initialize();
+
+        Map<String, Employee> map3 = new HashMap<>(map1);
+
+        map2.forEach(
+          (key, value) -> map3.merge(key, value, (v1, v2) ->
+          new Employee(v1.getId(),v2.getName()))
+        );
+
+        map3.entrySet().forEach(System.out::println);
+    }
+
+    private static void initialize() {
+        Employee employee1 = new Employee(1L, "Henry");
+        map1.put(employee1.getName(), employee1);
+        Employee employee2 = new Employee(22L, "Annie");
+        map1.put(employee2.getName(), employee2);
+        Employee employee3 = new Employee(8L, "John");
+        map1.put(employee3.getName(), employee3);
+
+        Employee employee4 = new Employee(2L, "George");
+        map2.put(employee4.getName(), employee4);
+        Employee employee5 = new Employee(1L, "Henry");
+        map2.put(employee5.getName(), employee5);
+    }
+
+}