From 2a12e9abd42822c1b7a3ddf321b975fe68907f35 Mon Sep 17 00:00:00 2001
From: myluckagain <myluckagain@gmail.com>
Date: Thu, 30 Aug 2018 03:56:21 +0500
Subject: [PATCH] BAEL-2151 (#5087)

BAEL-2151
---
 .../LinesIntersectionService.java             | 21 ++++++++++
 .../LinesIntersectionServiceUnitTest.java     | 40 +++++++++++++++++++
 2 files changed, 61 insertions(+)
 create mode 100644 core-java/src/main/java/com/baeldung/linesintersection/LinesIntersectionService.java
 create mode 100644 core-java/src/test/java/com/baeldung/linesintersection/LinesIntersectionServiceUnitTest.java

diff --git a/core-java/src/main/java/com/baeldung/linesintersection/LinesIntersectionService.java b/core-java/src/main/java/com/baeldung/linesintersection/LinesIntersectionService.java
new file mode 100644
index 0000000000..e4fed5a22e
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/linesintersection/LinesIntersectionService.java
@@ -0,0 +1,21 @@
+package com.baeldung.linesintersection;
+
+import java.awt.Point;
+import java.util.Optional;
+
+public class LinesIntersectionService {
+
+    public Optional<Point> calculateIntersectionPoint(float m1, float b1, float m2, float b2) {
+
+        if (m1 == m2) {
+            return Optional.empty();
+        }
+        
+        float x = (b2 - b1) / (m1 - m2);
+        float y = m1 * x + b1;
+
+        Point point = new Point(Math.round(x), Math.round(y));
+
+        return Optional.of(point);
+    }
+}
diff --git a/core-java/src/test/java/com/baeldung/linesintersection/LinesIntersectionServiceUnitTest.java b/core-java/src/test/java/com/baeldung/linesintersection/LinesIntersectionServiceUnitTest.java
new file mode 100644
index 0000000000..90c93fe050
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/linesintersection/LinesIntersectionServiceUnitTest.java
@@ -0,0 +1,40 @@
+package com.baeldung.linesintersection;
+
+import java.awt.Point;
+import java.util.Optional;
+
+import org.junit.Test;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertEquals;
+
+public class LinesIntersectionServiceUnitTest {
+    private LinesIntersectionService service = new LinesIntersectionService();
+
+    @Test
+    public void givenNotParallelLines_whenCalculatePoint_thenPresent() {
+
+        float m1 = 0;
+        float b1 = 0;
+        float m2 = 1;
+        float b2 = -1;
+
+        Optional<Point> point = service.calculateIntersectionPoint(m1, b1, m2, b2);
+
+        assertTrue(point.isPresent());
+        assertEquals(point.get().x, 1);
+        assertEquals(point.get().y, 0);
+    }
+
+    @Test
+    public void givenParallelLines_whenCalculatePoint_thenEmpty() {
+        float m1 = 1;
+        float b1 = 0;
+        float m2 = 1;
+        float b2 = -1;
+
+        Optional<Point> point = service.calculateIntersectionPoint(m1, b1, m2, b2);
+
+        assertFalse(point.isPresent());
+    }
+}