add logging to the projects for issue#132

src/main/java/com/github/romankh3/image/comparison/ImageComparisonUtil.java

@@ -15,11 +15,16 @@
 import java.io.InputStream;
 import javax.imageio.ImageIO;
 import javax.swing.ImageIcon;
+import java.util.logging.*;
 
 /**
  * Tools for the {@link ImageComparison} object.
  */
 public final class ImageComparisonUtil {
+    /**
+     * The Logger object.
+     */
+    static Logger logger = Logger.getLogger("com.github.romankh3.image.comparison.ImageComparisonUtil");
 
     /**
      * Make a copy of the {@link BufferedImage} object.
@@ -45,19 +50,24 @@ public static BufferedImage readImageFromResources(String path) throws ImageComp
         File imageFile = new File(path);
         if (imageFile.exists()) {
             try {
+                logger.info("Read image form User Successfully.");
                 return ImageIO.read(imageFile);
             } catch (IOException e) {
+                logger.severe("Cannot read image from the file, path = "+ path);
                 throw new ImageComparisonException(String.format("Cannot read image from the file, path=%s", path), e);
             }
         } else {
             InputStream inputStream = ImageComparisonUtil.class.getClassLoader().getResourceAsStream(path);
             if (inputStream != null) {
                 try {
+                    logger.info("Reading image file from path.");
                     return ImageIO.read(inputStream);
                 } catch (IOException e) {
+                    logger.severe("Cannot read image from the file, path="+path);
                     throw new ImageComparisonException(String.format("Cannot read image from the file, path=%s", path), e);
                 }
             } else {
+                logger.severe("Image with path = "+ path + " not found");
                 throw new ImageNotFoundException(String.format("Image with path = %s not found", path));
             }
         }
@@ -75,11 +85,14 @@ public static void saveImage(File pathFile, BufferedImage image) throws ImageCom
         // make dir if it's not using from Gradle.
         boolean dirExists = dir == null || dir.isDirectory() || dir.mkdirs();
         if (!dirExists) {
+            logger.severe("Unable to create directory " + dir);
             throw new ImageComparisonException("Unable to create directory " + dir);
         }
         try {
+            logger.info("Write the result image to the file directory");
             ImageIO.write(image, "png", pathFile);
         } catch (IOException e) {
+            logger.severe("Cannot save image to path=" + pathFile.getAbsolutePath());
             throw new ImageComparisonException(
                     String.format("Cannot save image to path=%s", pathFile.getAbsolutePath()), e);
         }

src/test/java/com/github/romankh3/image/comparison/LogTest.java

@@ -0,0 +1,39 @@
+package com.github.romankh3.image.comparison;
+
+import com.github.romankh3.image.comparison.model.ImageComparisonResult;
+import com.github.romankh3.image.comparison.model.ImageComparisonState;
+import org.junit.jupiter.api.Test;
+
+import java.awt.image.BufferedImage;
+import java.io.File;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class LogTest {
+    @Test
+    public void logTest1(){
+        //load images to be compared:
+        try{
+            BufferedImage expectedImage = ImageComparisonUtil.readImageFromResources("expcted.png");
+            fail();
+        }
+        catch (Exception e){
+            assertEquals(e.getMessage(), "Image with path = expcted.png not found");
+        }
+    }
+
+    @Test
+    public void logTest2(){
+        //load images to be compared:
+        try{
+            BufferedImage expectedImage = ImageComparisonUtil.readImageFromResources("expected.png");
+            BufferedImage actualImage = ImageComparisonUtil.readImageFromResources("actul.jpg");
+            ImageComparisonResult imageComparisonResult1 = new ImageComparison(expectedImage, actualImage).compareImages();
+            fail();
+        }
+        catch (Exception e){
+            assertEquals(e.getMessage(), "Image with path = actul.jpg not found");
+        }
+    }
+
+}