Multi Client Development with Spring

1,472 views
1,376 views

Published on

No application is an island and this is more obvious today than ever as applications extend their reach into people's pockets, desktops, tablets, TVs, Blu-ray players and cars. What's a modern developer to do to support these many platforms? In this talk, join Josh Long to learn how Spring can extend your reach through (sometimes Spring Security OAuth-secured) RESTful services exposed through Spring MVC, HTML5 and client-specific rendering thanks to Spring Mobile, and powerful, native support for Android with Spring Android.

Josh Long is the Spring developer advocate. He is the lead author on Apress’ Spring Recipes, 2nd Edition, and a SpringSource committer and contributor. When he's not hacking on code, he can be found at the local Java User Group or at the local coffee shop. Josh likes solutions that push the boundaries of the technologies that enable them. His interests include scalability, BPM, grid processing, mobile computing and so-called "smart" systems. He blogs at blog.springsource.org or joshlong.com and on Twitter as @starbuxman.

Published in: Technology
0 Comments
4 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,472
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
60
Comments
0
Likes
4
Embeds 0
No embeds

No notes for slide

Multi Client Development with Spring

  1. 1. Josh Long (⻰龙之春) @starbuxman joshlong.com josh.long@springsource.com slideshare.net/joshlong Multi Client Development with Spring© 2013 SpringSource, by VMware
  2. 2. Josh Long (⻰龙之春) @starbuxman joshlong.comjosh.long@springsource.com slideshare.net/joshlong
  3. 3. Josh Long (⻰龙之春) @starbuxman joshlong.comjosh.long@springsource.com slideshare.net/joshlongContributor To:•Spring Integration•Spring Batch•Spring Hadoop•Activiti Workflow Engine
  4. 4. Why Are We Here? “ Software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification. ” -Bob Martin4
  5. 5. Why Are We Here? do NOT reinvent the Wheel!5
  6. 6. Spring’s aim:bring simplicity to java development data web tier batch integration & access & service tier mobile processing messaging / NoSQL / Big RIA Data The Spring framework the cloud lightweight traditional CloudFoundry Google App Engine tc Server WebSphere Amazon BeanStalk Tomcat JBoss AS CloudBees Jetty WebLogic (on legacy versions, too!) OpenShift 6
  7. 7. Spring Web Support7
  8. 8. Thin, Thick, Web, Mobile and Rich Clients: Web Core§ Spring Dispatcher Servlet • Objects don’t have to be web-specific. • Spring web supports lower-level web machinery: ‘ • HttpRequestHandler (supports remoting: Caucho, Resin, JAX RPC) • DelegatingFilterProxy. • HandlerInterceptor wraps requests to HttpRequestHandlers • ServletWrappingController lets you force requests to a servlet through the Spring Handler chain • OncePerRequestFilter ensures that an action only occurs once, no matter how many filters are applied. Provides a nice way to avoid duplicate filters • Spring provides access to the Spring application context using WebApplicationContextUtils, which has a static method to look up the context, even in environments where Spring isn’t managing the web components
  9. 9. Thin, Thick, Web, Mobile and Rich Clients: Web Core§ Spring provides the easiest way to integrate with your web framework of choice • Spring Faces for JSF 1 and 2 • Struts support for Struts 1 • Tapestry, Struts 2, Stripes, Wicket, Vaadin, Play framework, etc. • GWT, Flex
  10. 10. Thin, Thick, Web, Mobile and Rich Clients: Spring MVC 10
  11. 11. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { } 11
  12. 12. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”) public String processTheRequest() { // ... return “home”; } }GET http://127.0.0.1:8080/url/of/my/resource 12
  13. 13. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”, method = RequestMethod.GET) public String processTheRequest() { // ... return “home”; } }GET http://127.0.0.1:8080/url/of/my/resource 13
  14. 14. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”, method = RequestMethod.GET) public String processTheRequest( HttpServletRequest request) { String contextPath = request.getContextPath(); // ... return “home”; } }GET http://127.0.0.1:8080/url/of/my/resource 14
  15. 15. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”, method = RequestMethod.GET) public String processTheRequest( @RequestParam(“search”) String searchQuery ) { // ... return “home”; } }GET http://127.0.0.1:8080/url/of/my/resource?search=Spring 15
  16. 16. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/{id}”, method = RequestMethod.GET) public String processTheRequest( @PathVariable(“id”) Long id) { // ... return “home”; } }GET http://127.0.0.1:8080/url/of/my/2322 16
  17. 17. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/{id}” ) public String processTheRequest( @PathVariable(“id”) Long customerId, Model model ) { model.addAttribute(“customer”, service.getCustomerById( customerId ) ); return “home”; } @Autowired CustomerService service; }GET http://127.0.0.1:8080/url/of/my/232 17
  18. 18. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”, method = RequestMethod.GET) public String processTheRequest( HttpServletRequest request, Model model) { return “home”; } } 18
  19. 19. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”, method = RequestMethod.GET) public View processTheRequest( HttpServletRequest request, Model model) { return new XsltView(...); } } 19
  20. 20. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”, method = RequestMethod.GET) public ResponseEntity<byte[]> processTheRequest( HttpServletRequest request, Model model) { return new ResponseEntity<byte[]>( bytes, ...) ; } } 20
  21. 21. DEMO§ Demos • Simple Spring MVC based Application Not confidential. Tell everyone.
  22. 22. the new hotness... 22
  23. 23. dumb terminals ruled the earth.... 23
  24. 24. then something magical happened: the web 24
  25. 25. but the web didn’t know how to do UI state... so we hacked... 25
  26. 26. ....then the web leveled up 26
  27. 27. How Powerful is JavaScript? ...It Boots Linux!! 27
  28. 28. REST 28
  29. 29. Thin, Thick, Web, Mobile and Rich Clients: REST§ Origin • The term Representational State Transfer was introduced and defined in 2000 by Roy Fielding in his doctoral dissertation.§ His paper suggests these four design principles: • Use HTTP methods explicitly. • POST, GET, PUT, DELETE • CRUD operations can be mapped to these existing methods • Be stateless. • State dependencies limit or restrict scalability • Expose directory structure-like URIs. • URI’s should be easily understood • Transfer XML, JavaScript Object Notation (JSON), or both. • Use XML or JSON to represent data objects or attributes CONFIDENTIAL 29
  30. 30. REST on the Server§ Spring MVC is basis for REST support • Spring’s server side REST support is based on the standard controller model§ JavaScript and HTML5 can consume JSON-data payloads
  31. 31. REST on the Client§ RestTemplate • provides dead simple, idiomatic RESTful services consumption • can use Spring OXM, too. • Spring Integration and Spring Social both build on the RestTemplate where possible.§ Spring supports numerous converters out of the box • JAXB • JSON (Jackson)
  32. 32. Building clients for your RESTful services: RestTemplate§ Google search example RestTemplate restTemplate = new RestTemplate(); String url = "https://ajax.googleapis.com/ajax/services/search/web?v=1.0&q={query}"; String result = restTemplate.getForObject(url, String.class, "SpringSource");§ Multiple parameters RestTemplate restTemplate = new RestTemplate(); String url = "http://example.com/hotels/{hotel}/bookings/{booking}"; String result = restTemplate.getForObject(url, String.class, "42", “21”); CONFIDENTIAL 32
  33. 33. Thin, Thick, Web, Mobile and Rich Clients: RestTemplate§ RestTemplate class is the heart the client-side story • Entry points for the six main HTTP methods • DELETE - delete(...) • GET - getForObject(...) • HEAD - headForHeaders(...) • OPTIONS - optionsForAllow(...) • POST - postForLocation(...) • PUT - put(...) • any HTTP operation - exchange(...) and execute(...) CONFIDENTIAL 33
  34. 34. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/resource”, method = RequestMethod.GET) public @ResponseBody Customer processTheRequest( ... ) { Customer c = service.getCustomerById( id) ; return c; } @Autowired CustomerService service; } 34
  35. 35. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/someurl”, method = RequestMethod.POST) public String processTheRequest( @RequestBody Customer postedCustomerObject) { // ... return “home”; } }POST http://127.0.0.1:8080/url/of/my/someurl 35
  36. 36. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @RequestMapping(value=”/url/of/my/{id}”, method = RequestMethod.POST) public String processTheRequest( @PathVariable(“id”) Long customerId, @RequestBody Customer postedCustomerObject) { // ... return “home”; } }POST http://127.0.0.1:8080/url/of/my/someurl 36
  37. 37. The Anatomy of a Spring MVC @Controller Spring MVC configuration - config @Controller public class CustomerController { @ResponseStatus( HttpStatus.CREATED ) @RequestMapping(value=”/url/of/my/{id}”, method = RequestMethod.POST) public ResponseEntity<?> processTheRequest() { // ... } }POST http://127.0.0.1:8080/url/of/my/someurl 37
  38. 38. What About the Browsers, Man?• Problem: modern browsers only speak GET and POST• Solution: use Spring’s HiddenHttpMethodFilter only then send _method request parameter in the request<filter> <filter-name>hiddenHttpMethodFilter</filter-name> <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class> </filter> <filter-mapping> <filter-name>hiddenHttpMethodFilter</filter-name> <url-pattern>/</url-pattern> <servlet-name>appServlet</servlet-name> </filter-mapping>
  39. 39. DEMO§ Demos:• Spring REST service• Spring REST client Not confidential. Tell everyone.
  40. 40. Spring Mobile 40
  41. 41. Thin, Thick, Web, Mobile and Rich Clients: Mobile§ Best strategy? Develop Native • Fallback to client-optimized web applications§ Spring MVC 3.1 mobile client-specific content negotiation and rendering • for other devices • (there are other devices besides Android??) 41
  42. 42. DEMO§ Demos:• Mobile clients using client specific rendering• preferences, device resolver, site switching, device delegating view resolver Not confidential. Tell everyone.
  43. 43. Spring Android 43
  44. 44. Thin, Thick, Web, Mobile and Rich Clients: Mobile § Spring REST is ideal for mobile devices § Spring MVC 3.1 mobile client-specific content negotiation and rendering • for other devices § Spring Android • RestTemplate 44
  45. 45. OK, so..... 45
  46. 46. Thin, Thick, Web, Mobile and Rich Clients: Mobile CustomerServiceClient - client! private <T> T extractResponse( ResponseEntity<T> response) {! ! if (response != null && response().value() == 200) {! ! ! return response.getBody();! ! }! ! throw new RuntimeException("couldnt extract response.");! }! @Override! public Customer updateCustomer(long id, String fn, String ln) {! ! String urlForPath = urlForPath("customer/{customerId}");! !! ! return extractResponse(this.restTemplate.postForEntity( urlForPath, new Customer(id, fn, ln), Customer.class, id));! } 46
  47. 47. Thin, Thick, Web, Mobile and Rich Clients: Mobile§ Demos:• consuming the Spring REST service from Android
  48. 48. And The REST of it• Spring Data REST - exposes (JPA, MongoDB, GemFire, Neo4J, Redis) repositories built on Spring Data repositories• Spring HATEOAS - take your REST-fu to the next level with support for HTTP as the engine of application state• Spring Social - provides connectivity and authentication support for OAuth• Spring Security OAuth - provides a way to expose RESTful endpoints through OAuth on the server-side
  49. 49. Josh Long (⻰龙之春) @starbuxman joshlong.comjosh.long@springsource.com slideshare.net/joshlong Questions?

×