{"id":9257,"date":"2013-03-01T16:00:43","date_gmt":"2013-03-01T14:00:43","guid":{"rendered":"http:\/\/www.javacodegeeks.com\/?p=9257"},"modified":"2013-03-01T09:21:27","modified_gmt":"2013-03-01T07:21:27","slug":"java-rest-assured-or-rest-very-easy","status":"publish","type":"post","link":"https:\/\/www.javacodegeeks.com\/2013\/03\/java-rest-assured-or-rest-very-easy.html","title":{"rendered":"Java: Rest-assured (or Rest-Very-Easy)"},"content":{"rendered":"

Recently I had to write some Java code to consume<\/span> REST services<\/b> over HTTP. I’ve decided to use the Client libraries of RestEasy<\/a>, the framework I use most of the time to expose REST services in Java, since it also implements the official JAX-RS<\/b> specification. I am very satisfied with the annotation driven approach that the specification defines and it makes exposing REST services a very pleasant task. But unluckily I cannot say that I like the client API<\/b> the same way. If you are lucky enough to be able to build a proxy client based on the interface implemented by the service, well, that’s not bad:
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import org.jboss.resteasy.client.ProxyFactory;\r\n...\r\n\/\/ this initialization only needs to be done once per VM\r\nRegisterBuiltin.register(ResteasyProviderFactory.getInstance());\r\n\r\nSimpleClient client = ProxyFactory.create(MyRestServiceInterface.class, 'http:\/\/localhost:8081');\r\nclient.myBusinessMethod('hello world');<\/pre>\n
Having a Proxy client similar to a JAX-WS one is good, I do agree. But most of the time, when we are consuming REST web service we do not have a Java interface to import. <\/b>All those Twitter, Google or whatever public rest services available out there are just HTTP endpoints. The way to go with RestEasy in these cases is to rely on the RestEasy Manual ClientRequest API:<\/p>\n
ClientRequest request = new ClientRequest('http:\/\/localhost:8080\/some\/path');\r\nrequest.header('custom-header', 'value');\r\n\r\n\/\/ We're posting XML and a JAXB object\r\nrequest.body('application\/xml', someJaxb);\r\n\r\n\/\/ we're expecting a String back\r\nClientResponse<String> response = request.post(String.class);\r\n\r\nif (response.getStatus() == 200) \/\/ OK!\r\n{\r\n   String str = response.getEntity();\r\n}<\/pre>\n
That is in my opinion a very verbose way to fetch what is most of the time, just a bunch of strings from the web. And it gets even worse if you need to include Authentication informations:<\/p>\n
\/\/ Configure HttpClient to authenticate preemptively\r\n\/\/ by prepopulating the authentication data cache.\r\n\r\n\/\/ 1. Create AuthCache instance\r\nAuthCache authCache = new BasicAuthCache();\r\n\r\n\/\/ 2. Generate BASIC scheme object and add it to the local auth cache\r\nBasicScheme basicAuth = new BasicScheme();\r\nauthCache.put('com.bluemonkeydiamond.sippycups', basicAuth);\r\n\r\n\/\/ 3. Add AuthCache to the execution context\r\nBasicHttpContext localContext = new BasicHttpContext();\r\nlocalContext.setAttribute(ClientContext.AUTH_CACHE, authCache);\r\n\r\n\/\/ 4. Create client executor and proxy\r\nhttpClient = new DefaultHttpClient();\r\nApacheHttpClient4Executor executor = new ApacheHttpClient4Executor(httpClient, localContext);\r\nclient = ProxyFactory.create(BookStoreService.class, url, executor);<\/pre>\n
I have found that Rest-assured<\/a><\/b> provide a much nicer API to write client invocations. Officially the aim of the project is to create a testing and validating framework<\/b>; and most of the tutorials out there are covering those aspects, like the recent Heiko Rupp’s one: http:\/\/pilhuhn.blogspot.nl\/2013\/01\/testing-rest-apis-with-rest-assured.html<\/a>. I suggest yout, instead, to use it as a development tool to experiment and write REST invocation very rapidly.<\/b> What is important to know about rest-assured:<\/p>\n