Perbandingan Antara Spring dan Spring Boot

Pengaturcaraan

1. Gambaran keseluruhan

Dalam penulisan ini, kita akan melihat perbezaan antara kerangka Spring standard dan Spring Boot.

Kami akan memfokuskan dan membincangkan bagaimana modul Spring, seperti MVC dan Security, berbeza ketika digunakan pada Spring inti berbanding ketika digunakan dengan Boot.

2. Apa itu Musim Bunga?

Ringkasnya, kerangka Spring menyediakan dukungan infrastruktur yang komprehensif untuk mengembangkan aplikasi Java .

Ia dilengkapi dengan beberapa ciri menarik seperti Dependency Injection dan modul di luar kotak seperti:

  • Musim bunga JDBC
  • Spring MVC
  • Keselamatan Musim Bunga
  • Musim bunga AOP
  • ORM musim bunga
  • Ujian Musim Bunga

Modul ini secara drastik dapat mengurangkan masa pengembangan aplikasi.

Sebagai contoh, pada awal pengembangan web Java, kita perlu menulis banyak boilerplate code untuk memasukkan catatan ke dalam sumber data. Tetapi dengan menggunakan JDBCTemplate modul Spring JDBC kita dapat mengurangkannya menjadi beberapa baris kod dengan hanya beberapa konfigurasi.

3. Apakah Spring Boot?

Spring Boot pada dasarnya adalah lanjutan dari rangka Spring yang menghilangkan konfigurasi plat boiler yang diperlukan untuk menyiapkan aplikasi Spring.

Ia memerlukan pandangan berpandangan platform Spring yang membuka jalan untuk eko-sistem pembangunan yang lebih pantas dan lebih efisien .

Berikut adalah beberapa ciri dalam Spring Boot:

  • Pergantungan 'starter' yang dikemukakan untuk mempermudah konfigurasi binaan dan aplikasi
  • Pelayan tertanam untuk mengelakkan kerumitan dalam penggunaan aplikasi
  • Metrik, Pemeriksaan kesihatan, dan konfigurasi luaran
  • Konfigurasi automatik untuk fungsi Spring - bila boleh

Mari kita kenal kedua-dua kerangka ini selangkah demi selangkah.

4. Pergantungan Maven

Pertama sekali, mari kita lihat kebergantungan minimum yang diperlukan untuk membuat aplikasi web menggunakan Spring:

 org.springframework spring-web 5.2.9.RELEASE   org.springframework spring-webmvc 5.2.9.RELEASE

Tidak seperti Spring, Spring Boot hanya memerlukan satu pergantungan untuk menjalankan aplikasi web dan berjalan:

 org.springframework.boot spring-boot-starter-web 2.3.4.RELEASE

Semua kebergantungan lain ditambahkan secara automatik ke arkib akhir semasa masa pembinaan.

Contoh lain yang baik ialah menguji perpustakaan. Kami biasanya menggunakan set perpustakaan Spring Test, JUnit, Hamcrest, dan Mockito. Dalam projek Spring, kita harus menambahkan semua perpustakaan ini sebagai pergantungan.

Tetapi dalam Spring Boot, kami hanya memerlukan pergantungan pemula untuk ujian untuk memasukkan perpustakaan ini secara automatik.

Spring Boot menyediakan sebilangan pergantungan starter untuk modul Spring yang berbeza. Beberapa yang paling biasa digunakan adalah:

  • spring-boot-starter-data-jpa
  • spring-boot-starter-security
  • spring-boot-starter-test
  • spring-boot-starter-web
  • spring-boot-starter-thymeleaf

Untuk senarai penuh pemula, lihat juga dokumentasi Spring.

5. Konfigurasi MVC

Mari terokai konfigurasi yang diperlukan untuk membuat aplikasi web JSP menggunakan Spring dan Spring Boot.

Spring memerlukan penentuan servlet penghantar, pemetaan, dan konfigurasi sokongan lain. Kita boleh melakukannya dengan menggunakan fail web.xml atau kelas Initializer :

public class MyWebAppInitializer implements WebApplicationInitializer { @Override public void onStartup(ServletContext container) { AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext(); context.setConfigLocation("com.baeldung"); container.addListener(new ContextLoaderListener(context)); ServletRegistration.Dynamic dispatcher = container .addServlet("dispatcher", new DispatcherServlet(context)); dispatcher.setLoadOnStartup(1); dispatcher.addMapping("/"); } }

We also need to add the @EnableWebMvc annotation to a @Configuration class and define a view-resolver to resolve the views returned from the controllers:

@EnableWebMvc @Configuration public class ClientWebConfig implements WebMvcConfigurer { @Bean public ViewResolver viewResolver() { InternalResourceViewResolver bean = new InternalResourceViewResolver(); bean.setViewClass(JstlView.class); bean.setPrefix("/WEB-INF/view/"); bean.setSuffix(".jsp"); return bean; } }

By comparison to all this, Spring Boot only needs a couple of properties to make things work, once we've added the web starter:

spring.mvc.view.prefix=/WEB-INF/jsp/ spring.mvc.view.suffix=.jsp

All the Spring configuration above is automatically included by adding the Boot web starter, through a process called auto-configuration.

What this means is that Spring Boot will look at the dependencies, properties, and beans that exist in the application and enable configuration based on these.

Of course, if we want to add our own custom configuration, then the Spring Boot auto-configuration will back away.

5.1. Configuring Template Engine

Let's now learn how to configure a Thymeleaf template engine in both Spring and Spring Boot.

In Spring we need to add the thymeleaf-spring5 dependency and some configurations for the view resolver:

@Configuration @EnableWebMvc public class MvcWebConfig implements WebMvcConfigurer { @Autowired private ApplicationContext applicationContext; @Bean public SpringResourceTemplateResolver templateResolver() { SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver(); templateResolver.setApplicationContext(applicationContext); templateResolver.setPrefix("/WEB-INF/views/"); templateResolver.setSuffix(".html"); return templateResolver; } @Bean public SpringTemplateEngine templateEngine() { SpringTemplateEngine templateEngine = new SpringTemplateEngine(); templateEngine.setTemplateResolver(templateResolver()); templateEngine.setEnableSpringELCompiler(true); return templateEngine; } @Override public void configureViewResolvers(ViewResolverRegistry registry) { ThymeleafViewResolver resolver = new ThymeleafViewResolver(); resolver.setTemplateEngine(templateEngine()); registry.viewResolver(resolver); } }

Spring Boot 1 required only the dependency of spring-boot-starter-thymeleaf to enable Thymeleaf support in a web application. But because of the new features in Thymeleaf3.0, we have to add thymeleaf-layout-dialect also as a dependency in a Spring Boot 2 web application. Alternatively, we can choose to add a spring-boot-starter-thymeleaf dependency that'll take care of all this for us.

Once the dependencies are in place, we can add the templates to the src/main/resources/templates folder and the Spring Boot will display them automatically.

6. Spring Security Configuration

For the sake of simplicity, we'll see how the default HTTP Basic authentication is enabled using these frameworks.

Let's start by looking at the dependencies and configuration we need to enable Security using Spring.

Spring requires both the standard spring-security-web and spring-security-config dependencies to set up Security in an application.

Next, we need to add a class that extends the WebSecurityConfigurerAdapter and makes use of the @EnableWebSecurity annotation:

@Configuration @EnableWebSecurity public class CustomWebSecurityConfigurerAdapter extends WebSecurityConfigurerAdapter { @Autowired public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception { auth.inMemoryAuthentication() .withUser("user1") .password(passwordEncoder() .encode("user1Pass")) .authorities("ROLE_USER"); } @Override protected void configure(HttpSecurity http) throws Exception { http.authorizeRequests() .anyRequest().authenticated() .and() .httpBasic(); } @Bean public PasswordEncoder passwordEncoder() { return new BCryptPasswordEncoder(); } }

Here we're using inMemoryAuthentication to set up the authentication.

Similarly, Spring Boot also requires these dependencies to make it work. But we need to define only the dependency ofspring-boot-starter-security as this will automatically add all the relevant dependencies to the classpath.

The security configuration in Spring Boot is the same as the one above.

If you need to know how the JPA configuration can be achieved in both Spring and Spring Boot, then check out our article A Guide to JPA with Spring.

7. Application Bootstrap

The basic difference in bootstrapping of an application in Spring and Spring Boot lies with the servlet. Spring uses either the web.xml or SpringServletContainerInitializer as its bootstrap entry point.

On the other hand, Spring Boot uses only Servlet 3 features to bootstrap an application. Let's talk about this in detail.

7.1. How Spring Bootstraps?

Spring supports both the legacy web.xml way of bootstrapping as well as the latest Servlet 3+ method.

Let's see the web.xml approach in steps:

  1. Servlet container (the server) reads web.xml
  2. The DispatcherServlet defined in the web.xml is instantiated by the container
  3. DispatcherServlet creates WebApplicationContext by reading WEB-INF/{servletName}-servlet.xml
  4. Finally, the DispatcherServlet registers the beans defined in the application context

Here's how Spring bootstraps using Servlet 3+ approach:

  1. The container searches for classes implementing ServletContainerInitializer and executes
  2. The SpringServletContainerInitializer finds all classes implementing WebApplicationInitializer
  3. The WebApplicationInitializer creates the context with XML or @Configuration classes
  4. The WebApplicationInitializer creates the DispatcherServlet with the previously created context.

7.2. How Spring Boot Bootstraps?

The entry point of a Spring Boot application is the class which is annotated with @SpringBootApplication:

@SpringBootApplication public class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); } }

By default, Spring Boot uses an embedded container to run the application. In this case, Spring Boot uses the public static void main entry-point to launch an embedded web server.

Also, it takes care of the binding of the Servlet, Filter, and ServletContextInitializer beans from the application context to the embedded servlet container.

Another feature of Spring Boot is that it automatically scans all the classes in the same package or sub packages of the Main-class for components.

Spring Boot provides the option of deploying it as a web archive in an external container as well. In this case, we have to extend the SpringBootServletInitializer:

@SpringBootApplication public class Application extends SpringBootServletInitializer { // ... }

Here the external servlet container looks for the Main-class defined in the META-INF file of the web archive and the SpringBootServletInitializer will take care of binding the Servlet, Filter, and ServletContextInitializer.

8. Packaging and Deployment

Finally, let's see how an application can be packaged and deployed. Both of these frameworks support the common package managing technologies like Maven and Gradle. But when it comes to deployment, these frameworks differ a lot.

For instance, the Spring Boot Maven Plugin provides Spring Boot support in Maven. It also allows packaging executable jar or war archives and running an application “in-place”.

Some of the advantages of Spring Boot over Spring in the context of deployment include:

  • Provides embedded container support
  • Provision to run the jars independently using the command java -jar
  • Option to exclude dependencies to avoid potential jar conflicts when deploying in an external container
  • Option to specify active profiles when deploying
  • Random port generation for integration tests

9. Conclusion

Dalam tutorial ini, kami telah mengetahui perbezaan antara Spring dan Spring Boot.

Dalam beberapa kata, kita dapat mengatakan bahawa Spring Boot hanyalah lanjutan dari Spring itu sendiri untuk menjadikan pengembangan, pengujian, dan penggunaan lebih mudah.