#22 mvc: reflection

my-framework/mvc-practice/src/main/java/org/example/annotation/Service.java

@@ -0,0 +1,11 @@
+package org.example.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.TYPE})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Service {
+}

my-framework/mvc-practice/src/main/java/org/example/model/User.java

@@ -0,0 +1,30 @@
+package org.example.model;
+
+import java.util.Objects;
+
+public class User {
+    private String userId;
+    private String name;
+
+    public User(String userId, String name) {
+        this.userId = userId;
+        this.name = name;
+    }
+
+    public boolean equalUser(User user) {
+        return this.equals(user);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof User)) return false;
+        User user = (User) o;
+        return Objects.equals(userId, user.userId) && Objects.equals(name, user.name);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(userId, name);
+    }
+}

my-framework/mvc-practice/src/main/java/org/example/service/HomeService.java

@@ -0,0 +1,7 @@
+package org.example.service;
+
+import org.example.annotation.Service;
+
+@Service
+public class HomeService {
+}

my-framework/mvc-practice/src/test/java/org/example/ReflectionTest.java

@@ -1,13 +1,22 @@
 package org.example;
 
+import org.assertj.core.api.Assertions;
 import org.example.annotation.Controller;
+import org.example.annotation.Service;
+import org.example.model.User;
 import org.junit.jupiter.api.Test;
 import org.reflections.Reflections;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.lang.annotation.Annotation;
+import java.util.Arrays;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
+import java.util.stream.Collectors;
+
+import static org.assertj.core.api.Assertions.*;
 
 public class ReflectionTest {
 
@@ -15,11 +24,47 @@ public class ReflectionTest {
 
     @Test
     void controllerScan() {
-        Reflections reflections = new Reflections("org.example");
-
-        Set<Class<?>> beans = new HashSet<>();
-        beans.addAll(reflections.getTypesAnnotatedWith(Controller.class));
+        Set<Class<?>> beans = getTypeAnnotationWith(List.of(Controller.class, Service.class));
 
         logger.debug("beans: [{}]", beans);
     }
+
+    @Test
+    void showClass() {
+        Class<User> clazz = User.class;
+
+        logger.debug(clazz.getName());
+
+        logger.debug("User all declared fields: [{}]", Arrays.stream(clazz.getDeclaredFields()).collect(Collectors.toList()));
+        logger.debug("User all declared constructor: [{}]", Arrays.stream(clazz.getDeclaredConstructors()).collect(Collectors.toList()));
+        logger.debug("User all declared method: [{}]", Arrays.stream(clazz.getDeclaredMethods()).collect(Collectors.toList()));
+    }
+
+    @Test
+    void load() throws ClassNotFoundException {
+        Class<User> clazz = User.class;
+
+        User user = new User("1", "test");
+        Class<? extends User> clazz2 = user.getClass();
+
+        Class<?> clazz3 = Class.forName("org.example.model.User");
+
+        logger.debug("clazz: [{}]", clazz);
+        logger.debug("clazz2: [{}]", clazz2);
+        logger.debug("clazz3: [{}]", clazz3);
+
+        assertThat(clazz == clazz2).isTrue();
+        assertThat(clazz == clazz3).isTrue();
+        assertThat(clazz2 == clazz3).isTrue();
+    }
+
+    private static Set<Class<?>> getTypeAnnotationWith(List<Class<? extends Annotation>> annotations) {
+        Reflections reflections = new Reflections("org.example");
+
+        Set<Class<?>> beans = new HashSet<>();
+
+        annotations.forEach(annotation -> beans.addAll(reflections.getTypesAnnotatedWith(annotation)));
+
+        return beans;
+    }
 }