final solution with tests

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/integerstreammedian/MedianOfIntegerStream.java

@@ -0,0 +1,42 @@
+package com.baeldung.algorithms.integerstreammedian;
+
+import java.util.PriorityQueue;
+import java.util.Queue;
+
+import static java.util.Comparator.reverseOrder;
+
+public class MedianOfIntegerStream {
+
+    private Queue<Integer> minHeap, maxHeap;
+
+    MedianOfIntegerStream() {
+        minHeap = new PriorityQueue<>();
+        maxHeap = new PriorityQueue<>(reverseOrder());
+    }
+
+    void add(int num) {
+        if (!minHeap.isEmpty() && num < minHeap.peek()) {
+            maxHeap.offer(num);
+            if (maxHeap.size() > minHeap.size() + 1) {
+                minHeap.offer(maxHeap.poll());
+            }
+        } else {
+            minHeap.offer(num);
+            if (minHeap.size() > maxHeap.size() + 1) {
+                maxHeap.offer(minHeap.poll());
+            }
+        }
+    }
+
+    double getMedian() {
+        int median;
+        if (minHeap.size() < maxHeap.size()) {
+            median = maxHeap.peek();
+        } else if (minHeap.size() > maxHeap.size()) {
+            median = minHeap.peek();
+        } else {
+            median = (minHeap.peek() + maxHeap.peek()) / 2;
+        }
+        return median;
+    }
+}

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/integerstreammedian/MedianOfIntegerStream2.java

@@ -1,25 +1,26 @@
-package com.baeldung.algorithms.datastreammedian;
+package com.baeldung.algorithms.integerstreammedian;
 
 import java.util.PriorityQueue;
 import java.util.Queue;
 
 import static java.util.Comparator.reverseOrder;
 
-public class DataStreamMedian {
+public class MedianOfIntegerStream2 {
 
     private Queue<Integer> minHeap, maxHeap;
 
-    DataStreamMedian() {
+    MedianOfIntegerStream2() {
         minHeap = new PriorityQueue<>();
         maxHeap = new PriorityQueue<>(reverseOrder());
     }
 
     void add(int num) {
-        minHeap.offer(num);
-        maxHeap.offer(minHeap.poll());
-
-        if (minHeap.size() < maxHeap.size()) {
+        if (minHeap.size() == maxHeap.size()) {
+            maxHeap.offer(num);
             minHeap.offer(maxHeap.poll());
+        } else {
+            minHeap.offer(num);
+            maxHeap.offer(minHeap.poll());
         }
     }