Thank you John. Awesome voice and clear explanations and slides. Before this course, I have tried many other courses, so I really mean this when I say it, this course is outstanding!
The apps built along the way mimic real world app s and the assignments help reinforce the learning along the way. It assumes some Java experience, although not much. Overall I feel competent in Spring after having taken this course. The sheer volume of content in this course is absurd. There are so many unique resources that you can take advantage of to help you learn Spring.
I have never seen an instructor work this hard to provide his students value from a course. All source code examples used in this course have been developed using the latest version of the Spring Framework — Spring Framework 5 and Spring Boot 2. You will see how modern Spring Framework development is done by leveraging the features of Spring Boot 2.
In addition to teaching you Spring Framework 5, you will learn about modern best practices used in enterprise application development. While JUnit 5 has been released for some time, many companies are still using JUnit 4. These techniques are best practices used by companies all over the world to build and manage large scale Spring Framework applications. In each lesson where we write code, you will have a link to GitHub with two branches in the Github repository.
You can see exactly what changed in each lesson. Each step of the way, you have a working example you can use for troubleshooting. In fact, you will get access to 24 and growing! Let us know if you liked the post. I never seen anything like this until you are using some download manager. Thanks a lot for sharing your knowledge. Good example. Of the same. I need a folder to convert into zip format.
Can you post that ASAP please. Then unzip it and add jars from it to your project. There is already an answer to your question. But if you are using maven or gradle Dependency Management tools , you have the snippets needed to use Spring Framework on the site you provided.
Just add these to your dependencies:. You can download latest version from here. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 5 years, 3 months ago.
You might even wonder if you need to configure all of them explicitly. You can find more information on the different implementations in the next section. MultipartResolver No default, explicit configuration is required LocaleResolver org. FixedThemeResolver HandlerMapping org.
BeanNameUrlHandlerMapping, org. RequestMappingHandlerMapping, org. RouterFunctionMapping HandlerAdapter org. HttpRequestHandlerAdapter, org. SimpleControllerHandlerAdapter, org. RequestMappingHandlerAdapter, org. ExceptionHandlerExceptionResolver, org.
ResponseStatusExceptionResolver, org. It does differ in some parts, however. Spring Boot enables org. StandardServletMultipartResolver by default. This can be disabled by declaring your own MultipartResolver or setting the spring.
Other properties in the spring. Next to that, it adds two ViewResolvers to the list. It adds org. BeanNameViewResolver and org. It still has the InternalResourceViewResolver which can be, partially, configured through using the spring.
You also learned how to configure org. In this section, you take a closer look at all the components involved in the request processing workflow. The API for org. HandlerMapping consists of a single method see Listing This method is called by DispatcherServlet to determine org. It is possible to have more than one handler mapping configured. Out of the box, Spring MVC provides four different implementations. Most of them are based on URL mappings. However, before looking at the different implementations, take a closer look at a URL to see which parts are important.
A request URL consists of several parts. The name of the application none, if it is the root application. By default, all the provided handler-mapping implementations use the path relative to the servlet context inside the servlet the servlet context relative path to resolve handlers.
Setting the alwaysUseFullPath property to true can change this behavior. A final feature shared among all implementations is that a default handler can be configured.
This is done by setting the defaultHandler property. When no handler can be found for an incoming request, it is always mapped to the default handler. This is optional, and it should be used with caution, especially when chaining multiple handler mappings. Only the last handler mapping should specify a default handler, or else the chain breaks. BeanNameUrlHandlerMapping implementation is one of the default strategies used by the dispatcher servlet. This implementation uses ant-style regular expressions to match the URL of the incoming request to the name of a bean.
It follows this algorithm. This means you need to use the name of the bean. You can provide the name for a bean by setting the name attribute on the org.
Bean annotation. A bean can have multiple names, and names can be written like an ant-style regular expression. Properties; import org. Configuration; import com. Listing shows a sample configuration.
HandlerMapping; import org. You need to explicitly configure the SimpleUrlHandlerMapping and pass it the mappings see the code in bold. If you have a lot of controllers, this configuration grows considerably. The advantage of this approach is that you have all your mapping in a single location.
It uses annotations to configure mappings. To map the com. Listing is the controller, and Listing shows the sample configuration. Controller; import org. RequestMapping; import org. HandlerFunctionAdapter implementation is a functional way to define handlers.
Listing shows the functional style of writing a handler to render the index page. RouterFunction; import org. ServerRequest; import org. HandlerAdapter is the glue between the dispatcher servlet and the selected handler. It removes the actual execution logic from the dispatcher servlet, which makes the dispatcher servlet infinitely extensible.
Consider this component the glue between the servlet and the actual handler implementation. HttpServletRequest; import javax. As Listing shows, the API consists of three methods. The supports method is called on each handler in the context by the dispatcher servlet; this is done to determine which HandlerAdapter can execute the selected handler. If the handler adapter can execute the handler, the handle method is called to execute the selected handler.
The execution of the handler can lead to org. ModelAndView being returned. However, some implementations always return null, indicating the response was already sent to the client. The result is sent back to the client as a Last-Modified request header and compared with the If-Modified-Since request header. If there was a modification, the content is regenerated and resent to the client; otherwise, an HTTP Response Code Not Modified is sent back to the client. This is particularly useful when the dispatcher servlet serves static resources, which save bandwidth.
HttpRequestHandlerAdapter knows how to execute org. HttpRequestHandler instances. However, there are two implementations of the org. HttpRequestHandler interface that you also use. SimpleControllerHandlerAdapter knows how to execute org. Controller implementations. It returns org. ModelAndView from the handleRequest method of the controller instance.
Servlet instances in the application context and put them behind the dispatcher servlet. To execute those servlets, you need org. It knows how to execute javax. Servlet, and it always returns null because it expects the servlet to handle the response itself. HandlerFunctionAdapter knows how to execute org. HandlerFunction instances. ModelAndView based on org. ServerResponse from the handler function. RequestMappingHa ndlerAdapter executes methods annotated with org.
It converts method arguments and gives easy access to the request parameters. The return value of the method is converted or added to the org. ModelAndView implementation internally created by this handler adapter.
The whole binding and converting process is configurable and flexible; the possibilities are explained in Chapters 5 and 6. MultipartResolver strategy interface determines whether an incoming request is a multipart file request for file uploads , and if so, it wraps the incoming request in org. The wrapped request can then get easy access to the underlying multipart files from the form.
File uploading is explained in Chapter 7. The isMultipart method is invoked to determine whether an incoming request is a multipart request. If it is, then the resolveMultipart method is called, which wraps the original request in MultipartHttpServletRequest.
Finally, when the request has been handled, the cleanupMultipart method is invoked to clean up any used resources. It enables easy configuration of several aspects of the Commons FileUpload library.
StandardServletMultipartResolv er merely serves as a wrapper around this standard approach, so that it is transparently exposed. LocaleResolver strategy interface determines which java. Locale to render the page. In most cases, it resolves validation messages or labels in the application.
Locale; import javax. The API consists of two methods that each play a role in storing and retrieving the current java. The setLocale method is called when you want to change the current locale.
UnsupportedOperationException is thrown. AcceptHeaderLocaleResolver implementation simply delegates to the getLocale method of the current javax. CookieLocaleResolver implementation uses javax. Cookie to store the locale to use. This is particularly useful in cases where you want an application to be as stateless as possible. The actual value is stored on the client side, and it is sent to you with each request.
This resolver allows the locale to be changed you can find more information on this in Chapter 6. This resolver also allows you to configure the name of the cookie and a default locale to use.
If no value can be determined for the current request i. FixedLocaleResolver is the most basic implementation of org. It allows you to configure a locale to use throughout the whole application. This configuration is fixed; as such, it cannot be changed. SessionLocaleResolver implementation uses the javax.
HttpSession to store the value of the locale. The name of the attribute, as well as a default locale, can be configured. This resolver also lets you change the locale see Chapter 6 for more information. ThemeResolver strategy interface determines which theme to render the page.
How to apply theming is explained in Chapter 8. If no theme name can be resolved, then this resolver uses the hardcoded default theme. Listing shows the API for org. ThemeResolver, which is similar to the org. LocaleResolver API. You call the setThemeName method when you want to change the current theme. If changing the theme is not supported, it throws java. The Spring Framework invokes the resolveThemeName method when it needs to resolve the current theme.
This is mainly done by using the theme JSP tag. CookieThemeResolver uses javax. Cookie to store the theme to use. This is particularly useful where you want your application to be as stateless as possible. The actual value is stored on the client side and sent to you with each request. This resolver allows the theme to be changed; you can find more information on this in Chapters 6 and 8.
This resolver also allows you to configure the name of the cookie and a theme locale to use. FixedThemeResolver is the most basic implementation of org. It allows you to configure a theme to use throughout the whole application. SessionThemeResolver uses javax. HttpSession to store the value of the theme. The name of the attribute, as well as a default theme, can be configured. You can use a HandlerExceptionResolver for this. The API see Listing consists of a single method that is called on the org.
HandlerExceptionResolvers detected by the dispatcher servlet. The resolver can choose to handle the exception itself or to return an org. ModelAndView implementation that contains a view to render and a model generally containing the exception thrown. Figure shows the different implementations provided by the Spring Framework.
Each works in a slightly different way, just as each is configured differently see Chapter 6 for more information. HandlerExceptionResolver implementations together. This resolver does not provide an actual implementation or added functionality; instead, it merely acts as a wrapper around multiple implementations when multiple implementations are configured. RequestToV iewNameTranslator tries to determine a view name from the incoming request. You can find more information about views in Chapter 8.
It simply takes the view name returned from the handler and tries to resolve it to an actual view implementation if no concrete org. View is returned. For more information on view resolving, refer to Chapter 8. This API see Listing is pretty simple and consists of a single method. This method takes the view name and currently selected locale see also the LocaleResolver. This can resolve an actual View implementation. When there are multiple org. ViewResolvers configured, the dispatcher servlet calls them in turn until one of them returns a View to render.
Out of the box, Spring provides several implementations see Chapter 8 for more information. The flash map is cleared after the view is rendered.
Spring provides a single implementation, org. The controller processes the request, fills the model, and selects the view to render. While processing a request, DispatcherServlet uses a lot of different components to play its role. The most important components are HandlerMapping and HandlerAdapter; these components are the core components used to map and handle requests, respectively.
To apply crosscutting concerns, you can use HandlerInterceptor. After handling a request, a view needs to be rendered. A handler can return a View or the name of a view to render. In the latter situation, this name is passed to a ViewResolver to resolve to an actual view implementation. There is also basic support for flash-scoped variables. To make this possible, there is FlashMapManager.
For example, you might encounter exceptions. To handle those, you can use the HandlerExceptionResolver. The final components that play a role here are the LocaleResolver and ThemeResolver. Together, these enable internationalization and theming in your application. Upcoming chapters explain how to build controllers to handle requests and take a closer look at how to configure Spring MVC through Spring Boot.
Implementing Controllers Controllers play a crucial role in a web application: they execute the actual request, prepare the model, and select a view to render. In conjunction with the dispatcher servlet, controllers also play a crucial role in the request processing workflow. The controller is the glue between the core application and the web interface to the application.
This chapter looks at the two different controller approaches and covers the out-of-the-box implementations provided with the Spring Framework and as configured by Spring Boot. This chapter also looks at the supporting components for request processing. For example, we cover form submission and how to apply internationalization I18N. This action could be a form submission, clicking a link, or simply accessing a page.
The controller selects or updates the data needed for the view. It also selects the name of the view to render or can render the view itself. With Spring MVC, we have two options when writing controllers. We can either implement an interface or put an annotation on the class.
The interface is org. Controller, and the annotation is org. The main focus of this. However, we feel that we still need to mention the interface-based approach. Although both approaches work for implementing a controller, there are two major differences between them. The first difference is about flexibility, and the second is about mapping URLs to controllers. Annotation-based controllers allow very flexible method signatures, whereas the interface-based approach has a predefined method on the interface that we must implement.
Getting access to other interesting collaborators is harder but not impossible! For the interface-based approach, we must do explicit external mapping of URLs to these controllers; in general, this approach is combined with org.
Having all the URLs in a single location is one advantage the interface-based approach has over the annotation-based approach. The annotation-based approach has its mappings scattered throughout the codebase, which makes it harder to see which URL is mapped to which request-handling method. The advantage of annotation-based controllers is that you can see which URLs it is mapped to when you open a controller.
This section shows how to write both types of controllers and how to configure basic view controllers. Controller interface. Listing shows the API for that interface. When implementing this interface, we must implement the handleRequest method. This method needs to return an org. ModelAndView object or null when the controller handles the response itself. HttpServletResponse; import org. If we take com. IndexController and create an interface-based controller out of it, it would look something like what you see in Listing We implement the handleRequest method and return an instance of ModelAndView with a view name.
ModelAndView; import org. In addition to writing this controller, we would need to configure an instance of org. We would also need to make sure that org. SimpleControllerHandlerAdapter is registered to execute the interface-based controllers this is registered by default.
The sample given here is straightforward. Now imagine a controller that has some page flow. In that case, we would need to check whether the request is a GET or POST request; based on that, we would need to execute different controller logic. With large controllers, this can become cumbersome. Table shows the Controller implementations that ship with the framework.
ParameterizableViewController A controller that returns a configured view name. ServletForwardingController A controller implementation that forwards the request to a named servlet, which can be a servlet without any mapping.
It is useful if you want to use the Spring MVC infrastructure to dispatch requests and apply interceptors. ServletWrappingController A controller implementation that wraps and manages a servlet implementation. Controller annotation on that class.
Also, we need to add an org. RequestMapping annotation to the class, a method, or both. Listing shows an annotation-based approach to our IndexController. The method has no required parameters, and we can return anything we want; for now, we want to return a ModelAndView.
The mapping is in the controller definition, and we need an instance of org. RequestMappingHandlerMapping to interpret these mappings registered by default. If we had a large application with more of these views, it would become cumbersome to maintain and write these. Spring MVC can help us here. Enabling us simply to add org. ParameterizableViewController to our configuration and to configure it accordingly. So how does it work? The explicit naming makes it possible for org. Again, Spring MVC is here to help us.
We can override the addViewControllers method one of the methods of org. Listing shows how to do this. ViewControllerRegistry; import org. The result is the same. However, the second approach is easier and less cumbersome to use than the first one. For example, how should a method be mapped to an incoming request? Several things could be a factor here, including the URL, the method used e.
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