diff --git a/problems/java/number-of-1-bits.java b/problems/java/number-of-1-bits.java
new file mode 100644
index 0000000..57862d9
--- /dev/null
+++ b/problems/java/number-of-1-bits.java
@@ -0,0 +1,13 @@
+public class Solution {
+    public int hammingWeight(int n) {
+        int bits = 0;
+
+        for (int i = 0; i < 32; ++i) {
+            if ((n & (1 << i)) != 0) {
+                ++bits;
+            }
+        }
+
+        return bits;
+    }
+}