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POHow to code a URL HTTP Get with Groovy considering inaccesible or down servers?
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copied!<p>I am implementing an API call to the MailChimp API in my web application. But this question is valid for any call to an API which accepts a simple HTTP GET. </p> <p>I would like to catch any errors and allow my application to continue without issues even if the API call failed, The mailchimp servers and down, slow or unavailable.</p> <p><a href="http://apidocs.mailchimp.com/api/" rel="nofollow">MailChimp API</a> Returns a serialized JSON Object. This is my code. </p> <pre><code>def listSubscribe = { apiurl, apikey, listid, email -> def url = "${apiurl}?method=listSubscribe&apikey=${apikey}&id=${listid}&email_address=${email}" } try { def url = new URL(listSubscribe(apiUrl,apiKey,listId,email)) return (url.text == 'true') ? true : false } catch (MalformedURLException e) { return false } catch (java.net.UnknownHostException e) { return false } </code></pre> <p>Should I perform any other try/catch? How can I improve my code to make it safer for inaccesible API calls?</p> <h1>Solution</h1> <p>In order to make the call asynchronous and since I am using this code inside a Grails application I created a <a href="http://grails-plugins.github.com/grails-quartz/guide/index.html" rel="nofollow">Quartz Job</a> to execute the service containing the API Call. </p> <pre><code>class MailChimpListSubscribeJob { def mailChimpService def execute(context) { mailChimpService.listSubscribe(context.mergedJobDataMap.get('email')) } } </code></pre> <p>The Service now uses a timeout and catches the generic Exception:</p> <pre><code>class MailChimpService { def grailsApplication def listSubscribe(email_address) { def apiurl = grailsApplication.config.mailchimp.apiUrl def apikey = grailsApplication.config.mailchimp.apiKey def listid = grailsApplication.config.mailchimp.listId listSubscribe(apiurl, apikey, listid, email_address) } def listSubscribe(apiurl, apikey, listid, email) { try { def cmdurl = "${apiurl}?method=listSubscribe&apikey=${apikey}&id=${listid}&email_address=${email}" def url = new URL(cmdurl) def response = url.getText(connectTimeout: 4 * 1000, readTimeout: 4 * 1000) return (response == 'true') ? true : false } catch (MalformedURLException e) { return false } catch (java.net.UnknownHostException e) { return false } catch (Exception e) { return false } } } </code></pre> <p>And inside my controllers:</p> <pre><code>MailChimpListSubscribeJob.triggerNow([email: 'myemail@example.com']) </code></pre>

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