BAEL-812: List of Rules Engines in Java (#2319)

* spring beans DI examples

* fix-1: shortening examples

* List of Rules Engines in Java

* BAEL-812: Openl-Tablets example added

* BAEL-812: artifacts names changed

spring-core/src/main/java/com/baeldung/autowired/TypesOfBeanInjectionSpring.java

@@ -0,0 +1,70 @@
+package com.baeldung.autowired;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.stereotype.Service;
+
+@SpringBootApplication
+public class TypesOfBeanInjectionSpring {
+    private final UserService userService;
+
+    @Autowired // the @Autowired can even be omitted, in case there's only one explicit constructor
+    public TypesOfBeanInjectionSpring(UserService userService) {
+        this.userService = userService;
+    }
+    
+    public static void main(String[] args) {
+        SpringApplication.run(TypesOfBeanInjectionSpring.class, args);
+    }
+
+    @Bean
+    CommandLineRunner runIt() {
+        return args -> {
+            userService.listUsers()
+                .stream()
+                .forEach(System.out::println);
+        };
+    }
+}
+
+class User {
+    private String name;
+
+    public User(String name) {
+        this.name = name;
+    }
+
+    // getters and setters ...
+    public String getName() {
+        return this.name;
+    }
+
+    public String toString() {
+        return name;
+    }
+
+}
+
+interface UserService {
+    List<User> listUsers();
+}
+
+@Service
+class UserServiceImpl implements UserService {
+
+    @Override
+    public List<User> listUsers() {
+        ArrayList<User> users = new ArrayList<>(3);
+        users.add(new User("Snoopy"));
+        users.add(new User("Woodstock"));
+        users.add(new User("Charlie Brown"));
+        return users;
+    }
+
+}

spring-core/src/test/java/com/baeldung/autowired/TypesOfBeanInjectionSpringIntegrationTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.autowired;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class TypesOfBeanInjectionSpringIntegrationTest {
+    @Autowired
+    UserService userService;
+
+    private static final String[] expected = new String[] { "Snoopy", "Woodstock", "Charlie Brown" };
+
+    @Test
+    public void givenDI_whenInjectObject_thenUserNamesAreListed() {
+        Assert.assertArrayEquals(expected, userService.listUsers()
+            .stream()
+            .map(User::getName)
+            .toArray());
+    }
+}