made changes to java reflection (#667)

core-java/src/test/java/com/baeldung/java/reflection/ReflectionTest.java

@@ -8,9 +8,7 @@ import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.Arrays;
 import java.util.List;
-import java.util.stream.Stream;
+import java.util.ArrayList;
-
-import static java.util.stream.Collectors.toList;
 import static org.junit.Assert.*;
 
 public class ReflectionTest {
@@ -24,7 +22,6 @@ public class ReflectionTest {
 
         assertTrue(Arrays.asList("name", "age")
           .containsAll(actualFieldNames));
-
     }
 
     @Test
@@ -311,16 +308,19 @@ public class ReflectionTest {
 
     }
 
-    private static List<String> getMethodNames(Method[] methods) {
-        return Stream.of(methods)
-          .map((Method::getName))
-          .collect(toList());
-    }
-
 	private static List<String> getFieldNames(Field[] fields) {
-        return Stream.of(fields)
+		List<String> fieldNames = new ArrayList<>();
-          .map(Field::getName)
+		for (Field field : fields)
-          .collect(toList());
+			fieldNames.add(field.getName());
+		return fieldNames;
+
+	}
+
+	private static List<String> getMethodNames(Method[] methods) {
+		List<String> methodNames = new ArrayList<>();
+		for (Method method : methods)
+			methodNames.add(method.getName());
+		return methodNames;
 	}
 
 }

reflection/pom.xml

@@ -1,30 +0,0 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
-	<modelVersion>4.0.0</modelVersion>
-	<groupId>com.baeldung</groupId>
-	<artifactId>reflection</artifactId>
-	<version>1.0</version>
-	<name>reflection</name>
-   <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-compiler-plugin</artifactId>
-        <version>3.3</version>
-        <configuration>
-          <source>8</source>
-          <target>8</target>
-        </configuration>
-      </plugin>
-    </plugins>
-  </build>
-	<dependencies>
-		<dependency>
-			<groupId>junit</groupId>
-			<artifactId>junit</artifactId>
-			<version>4.3</version>
-			<scope>test</scope>
-		</dependency>
-
-	</dependencies>
-</project>

reflection/src/main/java/com/baeldung/reflection/Animal.java

@@ -1,23 +0,0 @@
-package com.baeldung.reflection;
-
-public abstract class Animal implements Eating {
-
-    public static final String CATEGORY = "domestic";
-
-    private String name;
-
-    public Animal(String name) {
-        this.name = name;
-    }
-
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    protected abstract String getSound();
-
-}

reflection/src/main/java/com/baeldung/reflection/Bird.java

@@ -1,36 +0,0 @@
-package com.baeldung.reflection;
-
-public class Bird extends Animal {
-    private boolean walks;
-
-    public Bird() {
-        super("bird");
-    }
-
-    public Bird(String name, boolean walks) {
-        super(name);
-        setWalks(walks);
-    }
-
-    public Bird(String name) {
-        super(name);
-    }
-
-    @Override
-    public String eats() {
-        return "grains";
-    }
-
-    @Override
-    protected String getSound() {
-        return "chaps";
-    }
-
-    public boolean walks() {
-        return walks;
-    }
-
-    public void setWalks(boolean walks) {
-        this.walks = walks;
-    }
-}

reflection/src/main/java/com/baeldung/reflection/Eating.java

@@ -1,5 +0,0 @@
-package com.baeldung.reflection;
-
-public interface Eating {
-    String eats();
-}

reflection/src/main/java/com/baeldung/reflection/Goat.java

@@ -1,24 +0,0 @@
-package com.baeldung.reflection;
-
-public class Goat extends Animal implements Locomotion {
-
-    public Goat(String name) {
-        super(name);
-    }
-
-    @Override
-    protected String getSound() {
-        return "bleat";
-    }
-
-    @Override
-    public String getLocomotion() {
-        return "walks";
-    }
-
-    @Override
-    public String eats() {
-        return "grass";
-    }
-
-}

reflection/src/main/java/com/baeldung/reflection/Locomotion.java

@@ -1,5 +0,0 @@
-package com.baeldung.reflection;
-
-public interface Locomotion {
-    String getLocomotion();
-}

reflection/src/main/java/com/baeldung/reflection/Person.java

@@ -1,6 +0,0 @@
-package com.baeldung.reflection;
-
-public class Person {
-    private String name;
-    private int age;
-}

reflection/src/test/java/com/baeldung/reflection/ReflectionTest.java

@@ -1,323 +0,0 @@
-package com.baeldung.reflection;
-
-import org.junit.Test;
-
-import java.lang.reflect.*;
-import java.util.Arrays;
-import java.util.List;
-import java.util.stream.Stream;
-
-import static java.util.stream.Collectors.toList;
-import static org.junit.Assert.*;
-
-public class ReflectionTest {
-
-    @Test
-    public void givenObject_whenGetsFieldNamesAtRuntime_thenCorrect() {
-        Object person = new Person();
-        Field[] fields = person.getClass().getDeclaredFields();
-
-        List<String> actualFieldNames = getFieldNames(fields);
-
-        assertTrue(Arrays.asList("name", "age")
-          .containsAll(actualFieldNames));
-
-    }
-
-    @Test
-    public void givenObject_whenGetsClassName_thenCorrect() {
-        Object goat = new Goat("goat");
-        Class<?> clazz = goat.getClass();
-
-        assertEquals("Goat", clazz.getSimpleName());
-        assertEquals("com.baeldung.reflection.Goat", clazz.getName());
-        assertEquals("com.baeldung.reflection.Goat", clazz.getCanonicalName());
-    }
-
-    @Test
-    public void givenClassName_whenCreatesObject_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> clazz = Class.forName("com.baeldung.reflection.Goat");
-
-        assertEquals("Goat", clazz.getSimpleName());
-        assertEquals("com.baeldung.reflection.Goat", clazz.getName());
-        assertEquals("com.baeldung.reflection.Goat", clazz.getCanonicalName());
-    }
-
-    @Test
-    public void givenClass_whenRecognisesModifiers_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> goatClass = Class.forName("com.baeldung.reflection.Goat");
-        Class<?> animalClass = Class.forName("com.baeldung.reflection.Animal");
-        int goatMods = goatClass.getModifiers();
-        int animalMods = animalClass.getModifiers();
-
-        assertTrue(Modifier.isPublic(goatMods));
-        assertTrue(Modifier.isAbstract(animalMods));
-        assertTrue(Modifier.isPublic(animalMods));
-    }
-
-    @Test
-    public void givenClass_whenGetsPackageInfo_thenCorrect() {
-        Goat goat = new Goat("goat");
-        Class<?> goatClass = goat.getClass();
-        Package pkg = goatClass.getPackage();
-
-        assertEquals("com.baeldung.reflection", pkg.getName());
-    }
-
-    @Test
-    public void givenClass_whenGetsSuperClass_thenCorrect() {
-        Goat goat = new Goat("goat");
-        String str = "any string";
-
-        Class<?> goatClass = goat.getClass();
-        Class<?> goatSuperClass = goatClass.getSuperclass();
-
-        assertEquals("Animal", goatSuperClass.getSimpleName());
-        assertEquals("Object", str.getClass().getSuperclass().getSimpleName());
-
-    }
-
-    @Test
-    public void givenClass_whenGetsImplementedInterfaces_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> goatClass = Class.forName("com.baeldung.reflection.Goat");
-        Class<?> animalClass = Class.forName("com.baeldung.reflection.Animal");
-        Class<?>[] goatInterfaces = goatClass.getInterfaces();
-        Class<?>[] animalInterfaces = animalClass.getInterfaces();
-
-        assertEquals(1, goatInterfaces.length);
-        assertEquals(1, animalInterfaces.length);
-        assertEquals("Locomotion", goatInterfaces[0].getSimpleName());
-        assertEquals("Eating", animalInterfaces[0].getSimpleName());
-    }
-
-    @Test
-    public void givenClass_whenGetsConstructor_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> goatClass = Class.forName("com.baeldung.reflection.Goat");
-        Constructor<?>[] constructors = goatClass.getConstructors();
-
-        assertEquals(1, constructors.length);
-        assertEquals("com.baeldung.reflection.Goat", constructors[0].getName());
-    }
-
-    @Test
-    public void givenClass_whenGetsFields_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> animalClass = Class.forName("com.baeldung.reflection.Animal");
-        Field[] fields = animalClass.getDeclaredFields();
-
-        List<String> actualFields = getFieldNames(fields);
-
-        assertEquals(2, actualFields.size());
-        assertTrue(actualFields.containsAll(Arrays.asList("name", "CATEGORY")));
-    }
-
-    @Test
-    public void givenClass_whenGetsMethods_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> animalClass = Class.forName("com.baeldung.reflection.Animal");
-        Method[] methods = animalClass.getDeclaredMethods();
-        List<String> actualMethods = getMethodNames(methods);
-
-        assertEquals(4, actualMethods.size());
-        assertTrue(actualMethods.containsAll(Arrays.asList("getName",
-          "setName", "getSound", "makeSound")));
-    }
-
-    @Test
-    public void givenClass_whenGetsAllConstructors_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Constructor<?>[] constructors = birdClass.getConstructors();
-
-        assertEquals(3, constructors.length);
-    }
-
-    @Test
-    public void givenClass_whenGetsEachConstructorByParamTypes_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Constructor<?> cons1 = birdClass.getConstructor();
-        Constructor<?> cons2 = birdClass.getConstructor(String.class);
-        Constructor<?> cons3 = birdClass.getConstructor(String.class,
-          boolean.class);
-    }
-
-    @Test
-    public void givenClass_whenInstantiatesObjectsAtRuntime_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-
-        Constructor<?> cons1 = birdClass.getConstructor();
-        Constructor<?> cons2 = birdClass.getConstructor(String.class);
-        Constructor<?> cons3 = birdClass.getConstructor(String.class,
-          boolean.class);
-
-        Bird bird1 = (Bird) cons1.newInstance();
-        Bird bird2 = (Bird) cons2.newInstance("Weaver bird");
-        Bird bird3 = (Bird) cons3.newInstance("dove", true);
-
-        assertEquals("bird", bird1.getName());
-        assertEquals("Weaver bird", bird2.getName());
-        assertEquals("dove", bird3.getName());
-        assertFalse(bird1.walks());
-        assertTrue(bird3.walks());
-    }
-
-    @Test
-    public void givenClass_whenGetsPublicFields_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Field[] fields = birdClass.getFields();
-        assertEquals(1, fields.length);
-        assertEquals("CATEGORY", fields[0].getName());
-
-    }
-
-    @Test
-    public void givenClass_whenGetsPublicFieldByName_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Field field = birdClass.getField("CATEGORY");
-        assertEquals("CATEGORY", field.getName());
-
-    }
-
-    @Test
-    public void givenClass_whenGetsDeclaredFields_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Field[] fields = birdClass.getDeclaredFields();
-        assertEquals(1, fields.length);
-        assertEquals("walks", fields[0].getName());
-    }
-
-    @Test
-    public void givenClass_whenGetsFieldsByName_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Field field = birdClass.getDeclaredField("walks");
-        assertEquals("walks", field.getName());
-
-    }
-
-    @Test
-    public void givenClassField_whenGetsType_thenCorrect()
-      throws Exception {
-        Field field = Class.forName("com.baeldung.reflection.Bird")
-          .getDeclaredField("walks");
-        Class<?> fieldClass = field.getType();
-        assertEquals("boolean", fieldClass.getSimpleName());
-    }
-
-    @Test
-    public void givenClassField_whenSetsAndGetsValue_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Bird bird = (Bird) birdClass.newInstance();
-        Field field = birdClass.getDeclaredField("walks");
-        field.setAccessible(true);
-
-        assertFalse(field.getBoolean(bird));
-        assertFalse(bird.walks());
-
-        field.set(bird, true);
-
-        assertTrue(field.getBoolean(bird));
-        assertTrue(bird.walks());
-
-    }
-
-    @Test
-    public void givenClassField_whenGetsAndSetsWithNull_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Field field = birdClass.getField("CATEGORY");
-        field.setAccessible(true);
-
-        assertEquals("domestic", field.get(null));
-    }
-
-    @Test
-    public void givenClass_whenGetsAllPublicMethods_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Method[] methods = birdClass.getMethods();
-        List<String> methodNames = getMethodNames(methods);
-
-        assertTrue(methodNames.containsAll(Arrays
-          .asList("equals", "notifyAll", "hashCode",
-            "walks", "eats", "toString")));
-
-    }
-
-    @Test
-    public void givenClass_whenGetsOnlyDeclaredMethods_thenCorrect()
-      throws ClassNotFoundException {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        List<String> actualMethodNames = getMethodNames(birdClass.getDeclaredMethods());
-
-        List<String> expectedMethodNames = Arrays.asList("setWalks", "walks", "getSound", "eats");
-
-        assertEquals(expectedMethodNames.size(), actualMethodNames.size());
-        assertTrue(expectedMethodNames.containsAll(actualMethodNames));
-        assertTrue(actualMethodNames.containsAll(expectedMethodNames));
-
-    }
-
-    @Test
-    public void givenMethodName_whenGetsMethod_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Method walksMethod = birdClass.getDeclaredMethod("walks");
-        Method setWalksMethod = birdClass.getDeclaredMethod("setWalks",
-          boolean.class);
-
-        assertFalse(walksMethod.isAccessible());
-        assertFalse(setWalksMethod.isAccessible());
-
-        walksMethod.setAccessible(true);
-        setWalksMethod.setAccessible(true);
-
-        assertTrue(walksMethod.isAccessible());
-        assertTrue(setWalksMethod.isAccessible());
-
-    }
-
-    @Test
-    public void givenMethod_whenInvokes_thenCorrect()
-      throws Exception {
-        Class<?> birdClass = Class.forName("com.baeldung.reflection.Bird");
-        Bird bird = (Bird) birdClass.newInstance();
-        Method setWalksMethod = birdClass.getDeclaredMethod("setWalks",
-          boolean.class);
-        Method walksMethod = birdClass.getDeclaredMethod("walks");
-        boolean walks = (boolean) walksMethod.invoke(bird);
-
-        assertFalse(walks);
-        assertFalse(bird.walks());
-
-        setWalksMethod.invoke(bird, true);
-        boolean walks2 = (boolean) walksMethod.invoke(bird);
-
-        assertTrue(walks2);
-        assertTrue(bird.walks());
-
-    }
-
-    private static List<String> getMethodNames(Method[] methods) {
-        return Stream.of(methods)
-          .map((Method::getName))
-          .collect(toList());
-    }
-
-    private static List<String> getFieldNames(Field[] fields) {
-        return Stream.of(fields)
-          .map(Field::getName)
-          .collect(toList());
-    }
-
-}