Spring Security comes handy when you need to secure your RESTful web service. Let’s give this a go! In this example I’ll create a REST service exposing a Cat entity. It simply have name and colour field
{
"name" : "Tom",
"colour" : "Black"
};
Creating the Service
Setup a new maven project with following pom.xml. We’ll leverage Spring Boot to simplify the work.
Setup a main configuration class. This substitutes the old-fashioned spring context xml. Spring Boot will do a lot of under-the-hood work to setup various bits and pieces using auto configuration
guration
public class Application {
public static void main(String[] args) throws Exception {
SpringApplication.run(Application.class, args);
}
}
Now let’s create our Cat JPA entity
public class Cat {
@Id
private long id;
private String name = "";
private String colour = "";
/* .. getters & setters omitted .. */
}
Since we included dependency to spring-boot-starter-data-jpa, Spring Boot will automatically set us up with JPA with Hibernate implementation. Also note that on pom.xml we declared a dependency to hsqldb which will automatically give us datasource to an embedded HSQL database.
Next, let’s create a Spring Data repository for Cat.
esource
public interface CatRepository extends PagingAndSortingRepository {
}
Again, spring-boot-starter-data-jpa will auto setup spring-data-jpa for me, and it will automatically provide an implementation of the repository interface at runtime.
Take a note at the esource annotation. This annotation tells Spring Data REST to expose the repository as REST service as well.
Testing the Service
Now you’re ready to run the app using the embedded tomcat container. Run following maven command
Next, configure Spring Security so /cats/** path are protected to users with ROLE_USER only. We also setup two in-memory users: bob with ROLE_USER and admin with ROLE_USER and ROLE_ADMIN
Don’t forget to recompile and restart the app. Now you can test querying the cats repository will be forbidden for non-authenticated (anonymous) users:
The -H option passes a HTTP header as part of the request. Also note that the username and password joined by colon (:) is encoded into Base64 resulting in the string Ym9iOmJvYjEyMw==. This is the string “bob:bob123″ in plain text. You can use an to try it yourself.
Also note that similar to web browser the server gave us a JSESSIONID Cookie:
Different Security Permission for Read / Update Operations
What if you want to give ROLE_USER read-only access and full read/write to ROLE_ADMIN?
This can be achieved by using Spring Data Repository event handler class. You can invoke custom code prior / after certain operations executed on the repository. Let’s see how this works.
First enable method security on our SecurityConfig class. Add the hodSecurity(securedEnabled = true) annotation to SecurityConfig class:
ty
hodSecurity(securedEnabled = true)
public class SecurityConfig extends WebSecurityConfigurerAdapter {
...
}
Create a new CatEventHandler class annotated with Handler(Cat.class)
Handler(Cat.class)
("ROLE_ADMIN")
public class CatEventHandler {
private static final Logger LOG = LoggerFactory.getLogger(CatEventHandler.class);
e
public void handleBeforeSave(Cat c) {
LOG.debug("Before save " + c);
}
ate
public void handleBeforeCreate(Cat c) {
LOG.debug("Before create " + c);
}
kSave
public void handleBeforeLinkSave(Cat c) {
LOG.debug("Before link save " + c);
}
ete
public void handleBeforeDelete(Cat c) {
LOG.debug("Before delete " + c);
}
kDelete
public void handleBeforeLinkDelete(Cat c) {
LOG.debug("Before link delete " + c);
}
}
Few important things happening here:
All the .. methods will be invoked before the corresponding response is given to users
The (“ROLE_ADMIN”) annotation will ensure only users with ROLE_ADMIN can invoke all those methods in the class (although the method has nothing in it except a logging statement)
Let’s give this a try. Authenticate as bob:bob123 again and try creating a new Cat. Error will be presented:
I find it annoying to keep having to encode our username and password into Base64. I wanted a more simplified login such as posting u=bob&p=bob123 to http://localhost:8080/login.
Let’s try doing this.
Borrowing idea from , let’s create a LoginController
("/login")
public class LoginController {
private SecurityConfig securityConfig;
private AuthenticationDetailsSource authenticationDetailsSource = new WebAuthenticationDetailsSource();
private static final Logger LOG = LoggerFactory.getLogger(LoginController.class);
(method = RequestMethod.POST)
public String login(("u") String username,
("p") String password,
HttpServletRequest req) throws Exception {
// Force session creation so it's available to Spring Security post processor filter
req.getSession(true);
// Authenticate using AuthenticationManager configured on SecurityContext
AuthenticationManager authMgr = securityConfig.authenticationManagerBean();
UsernamePasswordAuthenticationToken authReq = new UsernamePasswordAuthenticationToken(username, password);
authReq.setDetails(authenticationDetailsSource.buildDetails(req));
Authentication authResp = authMgr.authenticate(authReq);
// If successful add the authentication response to context so the post processor filter
// can save it to session
SecurityContextHolder.getContext().setAuthentication(authResp);
return "Authentication successful";
}
...
}
Also create some exception handlers so login failure will produce 401 – Unauthorized HTTP status code.
Yay! Well done on making it this far. Hope you get a pretty decent looking REST API with minimal effort thanks to Spring. Don’t forget to always serve your API in HTTPS if deploying in production environment and secure it further with firewall if applicable.
As always you can browse the source code of this article on github:
Or clone it directly:
$ git clone https://github.com/gerrytan/rest1.git
Enjoy!
3 thoughts on “RESTful Web Service With Spring Data Rest and Spring Security”
Let’s say you have a unique index on the Cat.name. How would you respond with HttpStatus.CONFLICT when a duplicate Cat.name is posted?
Reply
My mistake. It appears Spring returns a “409 Conflict” by default
Let’s say you have a unique index on the Cat.name. How would you respond with HttpStatus.CONFLICT when a duplicate Cat.name is posted?
My mistake. It appears Spring returns a “409 Conflict” by default
Try creating a custom validator: http://docs.spring.io/spring-data/rest/docs/2.2.2.RELEASE/reference/html/#validation-chapter