Spring MVC 2017

AGENDA

INTRODUCING MVC AND SPRING MVC

What is MVC?
Introducing MVC and Spring MVC
What is MVC?

Introduction to Web Spring MVC
Spring MVC provides a clear separation between a model, view and controller
Provides both XML-based and annotation-based approaches.
Enriched by Spring application context.
Provides a broad range of pre-configured facilities.
Takes convention over configuration approach.
Uses open-close principle.
Main features
Benefits
Decoupling views and models
Reduces the complexity of your design
Makes code more flexible
Makes code more maintainable

What is MVC?
Introducing MVC and Spring MVC
Spring MVC WebApplicationContext Hierarchy

What is MVC?
Introducing MVC and Spring MVC
Spring MVC WebApplicationContext Hierarchy

Introducing MVC and Spring MVC
Spring MVC Request Life Cycle

Introducing MVC and Spring MVC
Intercepting requests with a HandlerInterceptor

Introducing MVC and Spring MVC
Spring MVC Request Life Cycle
BeanNameViewResolver
FreeMarkerViewResolver
InternalResourceViewResolver
JasperReportsViewResolver
ResourceBundleViewResolver
UrlBasedViewResolver
VelocityLayoutViewResolver
VelocityViewResolver
XmlViewResolver
XsltViewResolver

Introducing MVC and Spring MVC
Spring MVC Configuration
To configure Spring MVC support for web applications:
Configuring the root WebApplicationContext
Configuring the servlet filters required by Spring MVC
Configuring the dispatcher servlets within the application

DISPATCHERSERVLET, CONTROLLER, VIEW, MODEL

DispatcherServlet, Controller, View, Model
DispatcherServlet

DispatcherServlet, Controller, View, Model
DispatcherServlet Code Overview
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
...

DispatcherServlet, Controller, View, Model
DispatcherServlet Code Overview

DispatcherServlet, Controller, View, Model
DispatcherServlet Code Overview

DispatcherServlet, Controller, View, Model
DispatcherServlet Code Overview

DispatcherServlet, Controller, View, Model
DispatcherServlet Code Overview

DispatcherServlet, Controller, View, Model
Controllers
Controllers provide access to the application behavior that you typically define through a service interface.
Controllers interpret user input and transform it into a model that is represented to the user by the view.
Spring implements a controller in a very abstract way, which enables you to create a wide variety of controllers.
@RequestMapping("/contacts")
@Controller
public class ContactController {
private ContactService contactService;
@RequestMapping(method = RequestMethod.GET)
public String list(Model uiModel) {
List
contacts = contactService.findAll();
uiModel.addAttribute("contacts", contacts);
return "contacts/list";
}
@Autowired
public void setContactService(ContactService contactService) {
this.contactService = contactService;
}
}

DispatcherServlet, Controller, View, Model
View Examples

DispatcherServlet, Controller, View, Model
Model examples
Map
Populated by controllers
Contains all data needed by the „view“
Not containing business logic

DispatcherServlet, Controller, View, Model
Supported method return types
ModelAndView
Model
Map
View
String
void
….

INTERNATIONALIZATION(I18N) / THEMES /
TEMPLATES (APACHE TILES)

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Internationalization
Enable i18n in the early stage.
Properties files within the e.g /WEB-INF/i18n folder:
The application*.properties
The message*.properties

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Configuring i18n in DispatcherServlet

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Configuring i18n in DispatcherServlet

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Configuring i18n in DispatcherServlet

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Example View

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Using Themes

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Using Themes
FixedThemeResolver
SessionThemeResolver
CookieThemeResolver

Internationalization(i18n) / Themes / Templates (Apache Tiles)
Using templates

MAPPING OF URLS, VALIDATION SUPPORT

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping
consumes
consumes="application/json“;
consumes=“!application/json“;
"text/plain", "application/*;

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping
consumes
consumes="application/json“;
consumes=“!application/json“;
"text/plain", "application/*;
headers
headers="myHeader=myValue“;
headers="!myHeader=myValue“;
headers="myHeader", headers="!myHeader“;

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping
consumes
consumes="application/json“;
consumes=“!application/json“;
"text/plain", "application/*;
headers
headers="myHeader=myValue“;
headers="!myHeader=myValue“;
headers="myHeader", headers="!myHeader“;
method
RequestMethod.GET, RequestMethod.POST etc.

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping
consumes
consumes="application/json“;
consumes=“!application/json“;
"text/plain", "application/*;
headers
headers="myHeader=myValue“;
headers="!myHeader=myValue“;
headers="myHeader", headers="!myHeader“;
method
RequestMethod.GET, RequestMethod.POST etc.
name
params
params="myParam=myValue“;
params="!myParam=myValue“;

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping
consumes
consumes="application/json“;
consumes=“!application/json“;
"text/plain", "application/*;
headers
headers="myHeader=myValue“;
headers="!myHeader=myValue“;
headers="myHeader", headers="!myHeader“;
method
RequestMethod.GET, RequestMethod.POST etc.
name
params
params="myParam=myValue“;
params="!myParam=myValue“;
path

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping
consumes
consumes="application/json“;
consumes=“!application/json“;
"text/plain", "application/*;
headers
headers="myHeader=myValue“;
headers="!myHeader=myValue“;
headers="myHeader", headers="!myHeader“;
method
RequestMethod.GET, RequestMethod.POST etc.
name
params
params="myParam=myValue“;
params="!myParam=myValue“;
path
produces

Mapping of URLs, Validation support (JSR-349)
Mapping of URLs to the views
@RequestMapping
consumes
consumes="application/json“;
consumes=“!application/json“;
"text/plain", "application/*;
headers
headers="myHeader=myValue“;
headers="!myHeader=myValue“;
headers="myHeader", headers="!myHeader“;
method
RequestMethod.GET, RequestMethod.POST etc.
name
params
params="myParam=myValue“;
params="!myParam=myValue“;
path
produces
value

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example

Mapping of URLs, Validation support (JSR-349)
Mapping example
/spring-web/spring-web-3.0.5.jar

Spring MVC Annotations
Composed @RequestMapping Variants
@GetMapping
@PostMapping
@PutMapping
@DeleteMapping
@PatchMapping
@RequestMapping(method = RequestMethod.GET)
public Map
get() {
return …;
}
@GetMapping
public Map
get() {
return …;
}
@RequestMapping(method = RequestMethod.POST)
public String add(@Valid AppointmentForm appointment, BindingResult result) {
return …;
}
@PostMapping
public String add(@Valid AppointmentForm appointment, BindingResult result) {
return …;
}

Path Patterns
/myPath/*.do

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*
/hotels/{hotel}
/hotels/*

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*
/hotels/{hotel}
/hotels/*

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*
/hotels/{hotel}
/hotels/*
/**
/api/{a}/{b}/{c}

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*
/hotels/{hotel}
/hotels/*
/**
/api/{a}/{b}/{c}

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*
/hotels/{hotel}
/hotels/*
/**
/api/{a}/{b}/{c}
/public/**
/public/path3/{a}/{b}/{c}

Path Patterns
/myPath/*.do
/owners/*/pets/{petId}
/hotels/{hotel}/*
/hotels/{hotel}/**
/foo/bar*
/foo/*
/hotels/{hotel}
/hotels/*
/**
/api/{a}/{b}/{c}
/public/**
/public/path3/{a}/{b}/{c}

Spring MVC Annotations
@RequestBody
@PutMapping("/something")
public void handle(@RequestBody String body, Writer writer) throws IOException {
writer.write(body);
}
@PathVariable
@RequestParam
@RequestHeader
@RequestBody

Spring MVC Annotations
@ResponseBody
@GetMapping("/something")
@ResponseBody
public String helloWorld() {
return "Hello World";
}
HttpMessageConverter

Spring MVC Annotations
@RestController
@RestController

Spring MVC Annotations
@ModelAttribute on a method
// Add one attribute
// The return value of the method is added to the model under the name "account"
// You can customize the name via @ModelAttribute("myAccount")
@ModelAttribute
public Account addAccount(@RequestParam String number) {
return accountManager.findAccount(number);
}
// Add multiple attributes
@ModelAttribute
public void populateModel(@RequestParam String number, Model model) {
model.addAttribute(accountManager.findAccount(number));
// add more ...
}

Spring MVC Annotations
@ModelAttribute on method arguments
@PostMapping("/owners/{ownerId}/pets/{petId}/edit")
public String processSubmit(@ModelAttribute Pet pet) { }

Content Negotiation

Mapping of URLs, Validation support (JSR-349)
Configure JSR-349, “Bean Validation”
@Entity
@Table(name = "contact")
public class Contact implements Serializable {
private Long id;
private String firstName;
private String lastName;
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "ID")
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
@NotEmpty(message="{validation.firstname.NotEmpty.message}")
@Size(min=3, max=60, message="{validation.firstname.Size.message}")
@Column(name = "FIRST_NAME")
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
@NotEmpty(message="{validation.lastname.NotEmpty.message}")
@Size(min=1, max=40, message="{validation.lastname.Size.message}")
@Column(name = "LAST_NAME")
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
}

Mapping of URLs, Validation support (JSR-349)
Configure JSR-349, “Bean Validation”
public String update(@Valid Contact contact, ...
public String create(@Valid Contact contact, ...

FILE UPLOAD HANDLING

File Upload Handling
Overview
Tomcat 7 -> Servlet 3.0 -> Spring 3.1
Apache Commons FileUpload

File Upload Handling
Enable File Upload support

File Upload Handling
Enable File Upload support

File Upload Handling
Modifying Views for File Upload Support

File Upload Handling
Modifying Views for File Upload Support

File Upload Handling
Modifying Views for File Upload Support

SUPPORTING SERVLET 3.0 CODE-BASED (JAVA-BASED)
CONFIGURATION

Supporting Servlet 3.0 Code-Based (Java-Based) Configuration
Configuration
Advantages?

Supporting Servlet 3.0 Code-Based (Java-Based) Configuration
Configuration
Advantages?
Java синтаксис
Code IDE advantages
Flexibility
No need in full build and redeploy

Supporting Servlet 3.0 Code-Based (Java-Based) Configuration
Configuration
org.springframework.web.WebApplicationInitializer
org.springframework.web.SpringServletContainerInitializer
Advantages?
Java синтаксис
Code IDE advantages
Flexibility
No need in full build and redeploy

Supporting Servlet 3.0 Code-Based (Java-Based) Configuration
Configuration
public class MyWebAppInitializer implements WebApplicationInitializer {
@Override public void onStartup(ServletContext container) throws ServletException {
XmlWebApplicationContext appContext = new XmlWebApplicationContext();
appContext.setConfigLocation("/WEB-INF/spring/appServlet/servlet-context.xml");
ServletRegistration.Dynamic dispatcher =
container.addServlet("appServlet", new DispatcherServlet(appContext));
MultipartConfigElement multipartConfigElement =
new MultipartConfigElement(null, 5000000, 5000000, 0);
dispatcher.setMultipartConfig(multipartConfigElement);
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");
}
}

Supporting Servlet 3.0 Code-Based (Java-Based) Configuration
Configuration
public class MyWebAppInitializer implements WebApplicationInitializer {
@Override public void onStartup(ServletContext container) throws ServletException {
XmlWebApplicationContext appContext = new XmlWebApplicationContext();
appContext.setConfigLocation("/WEB-INF/spring/appServlet/servlet-context.xml");
ServletRegistration.Dynamic dispatcher =
container.addServlet("appServlet", new DispatcherServlet(appContext));
MultipartConfigElement multipartConfigElement =
new MultipartConfigElement(null, 5000000, 5000000, 0);
dispatcher.setMultipartConfig(multipartConfigElement);
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/");
}
}
appServlet
org.springframework.web.servlet.DispatcherServlet
contextConfigLocation
/WEB-INF/spring/appServlet/servlet-context.xml
1
5000000
appServlet
/

HANDLING EXCEPTIONS

Handling exceptions
Dealing with exceptions
Exceptions -> Status Codes
org.springframework.web.servlet.HandlerExceptionResolver: Exception -> ModelAndView
SimpleMappingExceptionResolver: Exceptions -> Views
@ExceptionHandler, @ControllerAdvice
@ResponseStatus

Handling exceptions
@ExceptionHandler & @ResponseStatus
@ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
@ExceptionHandler(DataAccessException.class)
public void handleDataAccessError(DataAccessException ex) {}
@ResponseStatus(value = HttpStatus.PAYMENT_REQUIRED, message = “I need money.”)
public class PaymentRequiredException {}

SPRING MVC AND SPRING SECURITY

Spring MVC and Spring Security
Introduction
Declaration Security
Support for many authentication and authorization schemes, such as basic, form-based, based on digests, JDBC and LDAP.
Support for security at the level of methods and security annotations JSR-250
Support for a one-time password
Container integration support
Supports anonymous sessions, simultaneous sessions, "remember me" mode, channel-level security and much more

Spring MVC and Spring Security
Libraries
Maven Dependencies for Spring Security

Spring MVC and Spring Security
Configuring Spring Security
Configure a filter in the web deployment descriptor:

Spring MVC and Spring Security
Configuring Spring Security

Spring MVC and Spring Security
Adding Login Functions to the Application

Spring MVC and Spring Security
Enable Method-Level Security
--> -->

Spring MVC and Spring Security
Enable Method-Level Security
--> -->

HELPFUL LINKS
http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle
http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller
http://en.wikipedia.org/wiki/Spring_Framework#Model-view-controller_framework