Bael 4241 (#11365)

* Added all class loaded listing

* Added all class loaded listing

Signed-off-by: saikatcse03 <saikatcse03@gmail.com>

* Updated class count

* Updated class count test and fixed tabs

* Removed spaces

* Updated version through Properties

Co-authored-by: saikat chakraborty <saikat.chakraborty@tesco.com>

core-java-modules/core-java-jvm-2/pom.xml

@@ -26,11 +26,23 @@
             <artifactId>jol-core</artifactId>
             <version>${jol-core.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.reflections</groupId>
+            <artifactId>reflections</artifactId>
+            <version>${reflections.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
     </dependencies>
 
     <properties>
         <assertj.version>3.6.1</assertj.version>
         <jol-core.version>0.10</jol-core.version>
+        <reflections.version>0.10.2</reflections.version>
+        <guava.version>31.0.1-jre</guava.version>
     </properties>
 
-</project>
+</project>

core-java-modules/core-java-jvm-2/src/main/java/com/baeldung/loadedclasslisting/ListLoadedClass.java

@@ -0,0 +1,35 @@
+package com.baeldung.loadedclasslisting;
+
+import java.io.IOException;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import org.reflections.Reflections;
+import org.reflections.scanners.SubTypesScanner;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.reflect.ClassPath;
+import com.google.common.reflect.ClassPath.ClassInfo;
+
+public class ListLoadedClass {
+
+    public ImmutableSet<ClassInfo> listClassLoaded() throws IOException {
+        return ClassPath.from(ListLoadedClass.class.getClassLoader())
+                .getAllClasses();
+    }
+
+    public Set<Class> listClassLoaded(String packageName) throws IOException {
+        return ClassPath.from(ClassLoader.getSystemClassLoader()).getAllClasses().stream()
+                .filter(clazz -> clazz.getPackageName().equals(packageName))
+                .map(ClassInfo::load)
+                .collect(Collectors.toSet());
+    }
+
+    public Set<Class> findAllClassesUsingReflectionsLibrary(String packageName) {
+        Reflections reflections = new Reflections(packageName, new SubTypesScanner(false));
+        return reflections.getSubTypesOf(Object.class)
+               .stream()
+               .collect(Collectors.toSet());
+    }
+    
+}

core-java-modules/core-java-jvm-2/src/test/java/com/baeldung/loadedclasslisting/ListLoadedClassUnitTest.java

@@ -0,0 +1,41 @@
+package com.baeldung.loadedclasslisting;
+
+import java.io.IOException;
+import java.util.Set;
+
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import com.baeldung.loadedclasslisting.ListLoadedClass;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.reflect.ClassPath;
+import com.google.common.reflect.ClassPath.ClassInfo;
+
+public class ListLoadedClassUnitTest {
+
+    private static final String PACKAGE_NAME = "com.baeldung.loadedclasslisting";
+
+    @Test
+    public void when_findAllClassesUsingReflectionsLibrary_thenSuccess() {
+        ListLoadedClass instance = new ListLoadedClass();
+        Set<Class> classes = instance.findAllClassesUsingReflectionsLibrary(PACKAGE_NAME);
+
+        Assertions.assertEquals(4, classes.size());
+    }
+
+    @Test
+    public void when_findAllClassesUsingGuavaLibrary_InPackage_thenSuccess() throws IOException {
+        ListLoadedClass instance = new ListLoadedClass();
+        Set<Class> classes = instance.listClassLoaded(PACKAGE_NAME);
+
+        Assertions.assertEquals(4, classes.size());
+    }
+
+    @Test
+    public void when_findAllClassesUsingGuavaLibrary_thenSuccess() throws IOException {
+        ListLoadedClass instance = new ListLoadedClass();
+        Set<ClassInfo> classes = instance.listClassLoaded();
+
+        Assertions.assertTrue(4<classes.size());
+    }
+}