From cdb37dddda62807df8686e7bb77cfcb0ba8cc4cd Mon Sep 17 00:00:00 2001
From: Anshul Bansal <smartdiscover17@gmail.com>
Date: Wed, 3 Apr 2019 17:14:31 +0300
Subject: [PATCH] BAEL-2800_Copying_a_HashMap_in_Java - methods added

---
 .../baeldung/copyinghashmap/CopyHashMap.java  | 25 ++++++++++--
 .../copyinghashmap/CopyHashMapUnitTest.java   | 38 ++++++++-----------
 2 files changed, 36 insertions(+), 27 deletions(-)

diff --git a/core-java-collections-2/src/main/java/com/baeldung/copyinghashmap/CopyHashMap.java b/core-java-collections-2/src/main/java/com/baeldung/copyinghashmap/CopyHashMap.java
index e6935afbe2..a1dc4fe6bb 100644
--- a/core-java-collections-2/src/main/java/com/baeldung/copyinghashmap/CopyHashMap.java
+++ b/core-java-collections-2/src/main/java/com/baeldung/copyinghashmap/CopyHashMap.java
@@ -8,8 +8,17 @@ import java.util.stream.Collectors;
 import org.apache.commons.lang3.SerializationUtils;
 
 public class CopyHashMap {
+    
+    public static HashMap copyUsingConstructor(HashMap originalMap) {
+        return new HashMap(originalMap);
+    }
+    
+    public static HashMap copyUsingClone(HashMap originalMap) {
+        return (HashMap) originalMap.clone();
+    }
 
-    public static HashMap basicCopy(HashMap originalMap, HashMap copyMap) {
+    public static HashMap copyUsingPut(HashMap originalMap) {
+        HashMap copyMap = new HashMap();
         Set<Map.Entry> entries = originalMap.entrySet();
         for(Map.Entry mapEntry: entries) {
             copyMap.put(mapEntry.getKey(), mapEntry.getValue());
@@ -18,8 +27,8 @@ public class CopyHashMap {
         return copyMap;
     }
     
-    
-    public static Map copyUsingPutAll(Map originalMap, Map copyMap) {
+    public static Map copyUsingPutAll(Map originalMap) {
+        HashMap copyMap = new HashMap();
         copyMap.putAll(originalMap);
         
         return copyMap;
@@ -34,8 +43,16 @@ public class CopyHashMap {
         return copyMap;
     }
     
+    public static HashMap copyMapAndConvertCmsToInches(HashMap originalMap) {
+        Set<Map.Entry> entries = originalMap.entrySet();
+        HashMap copyMap = (HashMap) entries
+            .stream()
+            .collect(Collectors.toMap(mapEntry -> mapEntry.getKey(), mapEntry -> (int)mapEntry.getValue()/2.54));
+        
+        return copyMap;
+    }
+    
     public static HashMap shallowCopy(HashMap originalMap) {
-        //return new HashMap(originalMap);
         return (HashMap) originalMap.clone();
     }
     
diff --git a/core-java-collections-2/src/test/java/com/baeldung/copyinghashmap/CopyHashMapUnitTest.java b/core-java-collections-2/src/test/java/com/baeldung/copyinghashmap/CopyHashMapUnitTest.java
index 57fccadaef..d49317b3dc 100644
--- a/core-java-collections-2/src/test/java/com/baeldung/copyinghashmap/CopyHashMapUnitTest.java
+++ b/core-java-collections-2/src/test/java/com/baeldung/copyinghashmap/CopyHashMapUnitTest.java
@@ -12,27 +12,6 @@ import com.google.common.collect.ImmutableMap;
 
 public class CopyHashMapUnitTest {
     
-    @Test
-    public void givenHashmap_whenCopy_thenCopyContainsAllMappings() {
-        
-        HashMap<String, String> colorMap = new HashMap<>();
-        colorMap.put("1", "Red");
-        colorMap.put("2", "Blue");
-        colorMap.put("3", "Green");
-        
-        System.out.println("ColorMap content : " + colorMap);
-        
-        HashMap<String, String> colorMapCopy = new HashMap<>();
-        colorMapCopy.put("1", "Orange");
-        colorMapCopy.put("4", "Black");
-        
-        colorMapCopy = CopyHashMap.basicCopy(colorMap, colorMapCopy);
-        
-        System.out.println("ColorMapCopy content : " +colorMapCopy);
-        
-        assertEquals(4, colorMapCopy.size());
-    }
-    
     @Test
     public void givenHashMap_whenShallowCopy_thenCopyisNotSameAsOriginal() {
         
@@ -80,7 +59,21 @@ public class CopyHashMapUnitTest {
         assertThat(employeeMapDeepCopy.get("employee1"))
         .isNotEqualTo(employeeMap.get("employee1"));
         
-    }  
+    } 
+    
+    @Test
+    public void givenHashMapWithValuesInCms_whenCopy_thenCopyMapShouldHaveValuesInInches() {
+        
+        HashMap<String, Integer> heightMap = new HashMap<>();
+        heightMap.put("emp1", 160);
+        heightMap.put("emp2", 165);
+        heightMap.put("emp3", 163);
+        HashMap heightMapInInches = CopyHashMap.copyMapAndConvertCmsToInches(heightMap);
+        
+        assertThat(heightMap).isNotEqualTo(heightMapInInches);
+        
+        assertThat(heightMap.get("emp1")/2.54).isEqualTo(heightMapInInches.get("emp1"));
+    } 
     
     @Test
     public void givenImmutableMap_whenCopyUsingGuava_thenCopyShouldNotChange() {
@@ -95,6 +88,5 @@ public class CopyHashMapUnitTest {
         assertThat(heightMapCopy).isSameAs(heightMap);
         
     }
-    
 
 }