GP-67 add AccountServiceDemoApp in order to show how ApplicationContext is created

Author: tboychuk

3-0-spring-framework/3-0-0-hello-spring-framework/src/main/java/com/bobocode/AccountServiceDemoApp.java

@@ -0,0 +1,34 @@
+package com.bobocode;
+
+import com.bobocode.config.ApplicationConfig;
+import com.bobocode.model.Account;
+import com.bobocode.service.AccountService;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+
+/**
+ * This is a demo application. It uses Spring to create an application context based on the configuration you provided
+ * when implementing this exercise. When everything is done and application context created successfully,
+ * it will get a "bean" (an object) of a {@link AccountService} from the context. That bean is used to find the richest
+ * account and show that everything is working as expected.
+ */
+public class AccountServiceDemoApp {
+    public static void main(String[] args) {
+        ApplicationContext context = initializeSpringContext();
+        AccountService accountService = context.getBean(AccountService.class);
+        Account account = accountService.findRichestAccount();
+        System.out.println("The riches person is " + account.getFirstName() + " " + account.getLastName());
+    }
+
+    /**
+     * In real applications, you will never initialize Spring context manually. We do this here for the sake of demo,
+     * so you can see that it's an object that implements {@link ApplicationContext} interface. As you can see,
+     * {@link ApplicationContext} has multiple implementations. In this exercise, we use the most popular way of
+     * configuring context – Java config with annotations.
+     *
+     * @return an instance of application context
+     */
+    private static ApplicationContext initializeSpringContext() {
+        return new AnnotationConfigApplicationContext(ApplicationConfig.class);
+    }
+}