I have an application which exposes RESTful actions using spring annotations and Spring MVC.
It looks like
#RequestMapping(value = "/example/{someId}",
method = RequestMethod.GET, consumes=MediaType.APPLICATION_JSON_VALUE,
produces=MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public void isRegisteredToThread(#PathVariable long someId, HttpServletResponse response) {
[something]
}
What I want is an automatically generated listing of all URL's, methods and available parameters - possibly within a WSDL. Is there a plugin or is it somehwere available?
WSDL is not done for rest, it's used for SOAP.
You might use WADL, but I really do not suggest it.
In my project I always use swagger (there is a release for spring). You may find more info here https://github.com/martypitt/swagger-springmvc and here http://blog.zenika.com/index.php?post/2013/07/11/Documenting-a-REST-API-with-Swagger-and-Spring-MVC
Give it a try.
As an alternative, if you don't need something web-based, you may try rest-shell (https://github.com/spring-projects/rest-shell)
You could take a look at the source code of RequestMappingEndpoint provided by the Spring Boot and see how Spring Boot reports the mappings.
Looking through that code one can see that the mappings (both handler and method mappings) can easily be obtained from the applicationContext
(using
applicationContext.getBeansOfType(AbstractUrlHandlerMapping.class)
and
applicationContext.getBeansOfType(AbstractHandlerMethodMapping.class)
respectively). After you have obtained the mapping you can process them anyway you like.
You might want to create a library that could include in all your projects that processes the mapping your organizations desired form
Related
I have endpoints in #RestControllers that look similar to this:
#RestController
#RequestMapping("/rest/x")
public class XApiController
{
// ...
#PostMapping(...)
#PreAuthorize("#apiAuthService.canAccessX(#headers)")
public void saveX(...)
{
// ...
}
}
These endpoints require the developer to make the HttpHeaders object available and name it correctly in the method declaration:
public void saveX(#RequestHeader HttpHeaders headers)
Our problem is that if this last step isn't done, the endpoint only fails at runtime when the endpoint is invoked. This means that issues from large refactors later (say, to change the HttpHeaders argument to HttpServletRequest) aren't easy to identify. Is there any way to tell Spring to validate these expressions are valid on app startup?
I suggest you to create integration tests and then invoke saveX from the test to verify this before you deploy an application.
I would also state my opinion that if you want to have testable code with good quality - try to get rid of SpringEL as soon as possible. In my experience this approach proved as poorly testable, hardly maintainable and also introducing unnecessary complications to your source code.
In modern spring framework there are lots of ways to avoid writing SpringEl.
Spring always validates all beans on start up. But your problem is not within validation your problem is test problem. The process of pre authorization is a runtime job. Spring can not know what to do with this expression spring just checks its syntax over SPEL rules.
You can create tests to check header.
You can increase your IDE inspection level of spring spel to error.
You can simply write a static method to get the headers without a rest parameter.
I d like to make a REST call once on application startup to retrieve some configuration parameters.
For example, we need to retrieve an entity called FleetConfiguration from another server. I d like to do a GET once and save the keep the data in memory for the rest of the runtime.
What s the best way of doing this in Spring? using Bean, Config annotations ..?
I found this for example : https://stackoverflow.com/a/44923402/494659
I might as well use POJOs handle the lifecycle of it myself but I am sure there s a way to do it in Spring without re-inventing the wheel.
Thanks in advance.
The following method will run once the application starts, call the remote server and return a FleetConfiguration object which will be available throughout your app. The FleetConfiguration object will be a singleton and won't change.
#Bean
#EventListener(ApplicationReadyEvent.class)
public FleetConfiguration getFleetConfiguration(){
RestTemplate rest = new RestTemplate();
String url = "http://remoteserver/fleetConfiguration";
return rest.getForObject(url, FleetConfiguration.class);
}
The method should be declared in a #Configuration class or #Service class.
Ideally the call should test for the response code from the remote server and act accordingly.
Better approach is to use Spring Cloud Config to externalize every application's configuration here and it can be updated at runtime for any config change so no downtime either around same.
We use Spring to implement REST controller, for example:
#Controller
#RequestMapping("/myservice")
public class MyController {
#RequestMapping(value = "foo", method = RequestMethod.GET)
public #ResponseBody string foo() {...}
}
I can call this service using spring RestTemplate, and it works fine, but I would prefer to invoke it using a proxy, instead of typeless invocation using string url:
// client code:
MyController proxy = getProxy("baseUrl", MyController.class);
String results = proxy.foo();
So the input to proxy generation is java interface with annotations describing REST details.
I read this article and it looks like all types of remote calls do have proxies, and all I need for REST is something like RestProxyFactoryBean, that would take my REST java interface and return type-safe proxy that uses RestTemplate as implementation.
The closest solution I found is JBoss RESTEasy.
But it seems to use different set of annotations, so I am not sure it will work with annotations I already have: #Controller, #RequestMapping.
Are there other options, or RESTEasy is the only one?
Note, I am spring newbie so some obvious spring things are pretty new to me.
Thank you.
Dima
You can try Feign by Netflix, a lightweight proxy-based REST client. It works declaratively through annotations, and it's used by Spring Cloud projects to interact with Netflix Eureka.
One of the reasons the REST paradigm was invented was because expirience with other remoting technologies (RMI, CORBA, SOAP) shows us that often, the proxy-based approach creates more problems than it solves.
Theoretically, a proxy makes the fact that a function call is remote transparent to its users, so they can use the function exactly the same way as if it were a local function call.
In practice however this promise cannot be fulfilled, because remote function calls simply have other properties than local calls. Network outages, congestion, timeouts, load problems to name just a few. If you choose to ignore all these things that can go wrong with remote calls, your code probably won't be very stable.
TL;DR: You probably shouldn't work with a proxy, it's not state of the art any more. Just use RestTemplate.
Here is a project trying to generate runtime proxies from the controller annotations (using RestTemplate in the background to handle proxy calls): spring-rest-proxy-client Very early in implementation though.
This seems to do it: https://swagger.io/swagger-codegen/, and swagger has many other nice things for REST API.
Have a look at https://github.com/ggeorgovassilis/spring-rest-invoker.
All you need is to register FactoryBean:
#Configuration
public class MyConfiguration {
#Bean
SpringRestInvokerProxyFactoryBean BankService() {
SpringRestInvokerProxyFactoryBean proxyFactory = new SpringRestInvokerProxyFactoryBean();
proxyFactory.setBaseUrl("http://localhost/bankservice");
proxyFactory.setRemoteServiceInterfaceClass(BankService.class);
return proxyFactory;
}
and after that you can autowire the interface class:
#Autowired
BookService bookService;
I also ended up making my own library for this. I wanted something that is as small as possible, adds only itself to classpath and no transitive dependencies.
A client is created like:
final StoreApi storeApi = SpringRestTemplateClientBuilder
.create(StoreApi.class)
.setRestTemplate(restTemplate)
.setUrl(this.getMockUrl())
.build();
And rest-requests will be performed when invoking the methods:
storeApi.deleteOrder(1234L);
The is supports both method signatures:
ResponseEntity<X> deleteOrder(Long)
X deleteOrder(Long)
I have a JIRA plugin that I'm developing that has a REST service. That service should be able to accept POSTed requests, unmarshall some data and store it. The seemingly suggested way to do this in JIRA is to make use of the Bandana persistence framework. According to this page, I should be able to simply define a setter that Spring should call to give me my Bandana manager.
#Path("/path")
public class SCMService {
private BandanaManager bandanaManager;
// setter called by Spring
public void setBandanaManager(BandanaManager bandanaManager) {
this.bandanaManager = bandanaManager;
}
//...More methods...
}
However, when I test this, the setter is never being called and my manager is null. I'm guessing this should be as simple as registering this service with Spring for injection somehow but I can't seem to find anything like that.
How would I get my setter called? Is there a better way to do this?
Er, I'm not sure that JIRA uses Bandana in that way, though Confluence does. You can certainly post data to a JIRA rest resource and then store it using properties tables
Something like this:
#POST
#Consumes (MediaType.APPLICATION_XML)
public Response createComponentAndIssues(#Context HttpServletRequest request, ...
I am trying to put a "Contract" on a method call. My web application is in Spring 3.
Is writing customs Annotations the right way to go. If so, any pointers( I didn't find anything in spring reference docs).
Should I use tools like "Modern Jass", JML ...? Again any pointers will be useful.
Thanks
Using Spring EL and Spring security could get you most of the way. Spring security defines the #PreAuthorize annotation which is fired before method invocation and allows you to use Spring 3's new expression engine, such as:
#PreAuthorize("#customerId > 0")
public Customer getCustomer(int customerId) { .. }
or far more advanced rules like the following which ensures that the passed user does not have role ADMIN.
#PreAuthorize("#user.role != T(com.company.Role).ADMIN)")
public void saveUser(User user) { .. }
You can also provide default values for your contract with the #Value annotation
public Customer getCustomer(#Value("#{434}") int customerId) { .. }
You can even reference system properties in your value expressions.
Setting up Spring security for this purpose is not to hard as you can just create a UserDetailsService that grants some default role to all users. Alternatively you could make you own custom Spring aspect and then let this use the SpelExpressionParser to check method values.
if you don't mind writing some parts of your Java web application in Groovy (which is possible with Spring) I would suggest using GContracts.
GContracts is a Design by Contract (tm) library entirely written in Java - without any dependencies to other libraries - and has full support for class invariants, pre- and postconditions and inheritance of those assertions.
Contracts for Java which is based on Modern Jass is one way to write contracts.
http://code.google.com/p/cofoja/
As per the writing of this reply, this is pretty basic. Hopefully this will improve as we go on.
I didn't find an ideal solution to this, interestingly it is a planned feature for the Spring framework (2.0 implemented patch):
http://jira.springframework.org/browse/SPR-2698
The best thing I suggest to use JSR 303 which is for bean validation. AFAIK there are two implementations for this:
Agimatec Validations
Hibernate Validator
There's a guide here for integrating it into Spring, I haven't followed it through but it looks ok:
http://blog.jteam.nl/2009/08/04/bean-validation-integrating-jsr-303-with-spring/
I personally recommend C4J for 2 reasons:
It has Eclipse plugin so you don't need to manually configure it.
The documentation is written in a clear, structured format so you can easily use it.
Her's the link to C4J