Add Difference Between Class.getResource() and ClassLoader.getResource() (#12669)

* Add Difference Between Class.getResource() and ClassLoader.getResource()

* Fix - replace System.out with Logger

* Fix - move code to a different module

core-java-modules/core-java-jvm-2/src/main/java/com/baeldung/resource/ClassGetResourceExample.java

@@ -0,0 +1,19 @@
+package com.baeldung.resource;
+
+import java.net.URL;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ClassGetResourceExample {
+
+    private static Logger logger = LoggerFactory.getLogger(ClassGetResourceExample.class);
+
+    public static void main(String[] args) {
+        URL resourceAbsolutePath = ClassGetResourceExample.class.getResource("/com/baeldung/resource/example.txt");
+        logger.info("Resource with absolute path = {}", resourceAbsolutePath);
+
+        URL resourceRelativePath = ClassGetResourceExample.class.getResource("example.txt");
+        logger.info("Resource with relative path = {}", resourceRelativePath);
+    }
+}

core-java-modules/core-java-jvm-2/src/main/java/com/baeldung/resource/ClassLoaderGetResourceExample.java

@@ -0,0 +1,21 @@
+package com.baeldung.resource;
+
+import java.net.URL;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ClassLoaderGetResourceExample {
+
+    private static Logger logger = LoggerFactory.getLogger(ClassLoaderGetResourceExample.class);
+
+    public static void main(String[] args) {
+        URL resourceAbsolutePath = ClassLoaderGetResourceExample.class.getClassLoader()
+            .getResource("com/baeldung/resource/example.txt");
+        logger.info("Resource with absolute path = {}", resourceAbsolutePath);
+
+        URL resourceRelativePath = ClassLoaderGetResourceExample.class.getClassLoader()
+            .getResource("example.txt");
+        logger.info("Resource with relative path = {}", resourceRelativePath);
+    }
+}

core-java-modules/core-java-jvm-2/src/main/resources/com/baeldung/resource/example.txt

@@ -0,0 +1 @@
+Baeldung

core-java-modules/core-java-jvm-2/src/test/java/com/baeldung/resource/ClassGetResourceUnitTest.java

@@ -0,0 +1,21 @@
+package com.baeldung.resource;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.net.URL;
+
+class ClassGetResourceUnitTest {
+
+    @Test
+    void givenRelativeResourcePath_whenGetResource_thenReturnResource() {
+        URL resourceRelativePath = ClassGetResourceExample.class.getResource("example.txt");
+        Assertions.assertNotNull(resourceRelativePath);
+    }
+
+    @Test
+    void givenAbsoluteResourcePath_whenGetResource_thenReturnResource() {
+        URL resourceAbsolutePath = ClassGetResourceExample.class.getResource("/com/baeldung/resource/example.txt");
+        Assertions.assertNotNull(resourceAbsolutePath);
+    }
+}

core-java-modules/core-java-jvm-2/src/test/java/com/baeldung/resource/ClassLoaderGetResourceUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.resource;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.net.URL;
+
+class ClassLoaderGetResourceUnitTest {
+
+    @Test
+    void givenRelativeResourcePath_whenGetResource_thenReturnNull() {
+        URL resourceRelativePath = ClassLoaderGetResourceExample.class.getClassLoader()
+            .getResource("example.txt");
+        Assertions.assertNull(resourceRelativePath);
+    }
+
+    @Test
+    void givenAbsoluteResourcePath_whenGetResource_thenReturnResource() {
+        URL resourceAbsolutePath = ClassLoaderGetResourceExample.class.getClassLoader()
+            .getResource("com/baeldung/resource/example.txt");
+        Assertions.assertNotNull(resourceAbsolutePath);
+    }
+}