Retry HTTP call on connection failure in sendHTTPReponse()

gistfile1.txt

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    public JSONObject sendHTTPCall(String urlString, String requestType, AbstractBuild build, BuildListener listener)
            throws IOException {
        
            return sendHTTPCall( urlString, requestType, build, listener, 1 );
    }
 
    public JSONObject sendHTTPCall(String urlString, String requestType, AbstractBuild build, BuildListener listener, int NumberOfAttempts)
            throws IOException {
        RemoteJenkinsServer remoteServer = this.findRemoteHost(this.getRemoteJenkinsName());
 
        if (remoteServer == null) {
            this.failBuild(new Exception("No remote host is defined for this job."), listener);
            return null;
        }
 
        HttpURLConnection connection = null;
 
        JSONObject responseObject = null;
 
        try {
            URL buildUrl = new URL(urlString);
            connection = (HttpURLConnection) buildUrl.openConnection();
 
            // if there is a username + apiToken defined for this remote host, then use it
            String usernameTokenConcat;
 
            if (this.getOverrideAuth()) {
                usernameTokenConcat = this.getAuth()[0].getUsername() + ":" + this.getAuth()[0].getPassword();
            } else {
                usernameTokenConcat = remoteServer.getAuth()[0].getUsername() + ":"
                        + remoteServer.getAuth()[0].getPassword();
            }
 
            if (!usernameTokenConcat.equals(":")) {
                // token-macro replacment
                usernameTokenConcat = TokenMacro.expandAll(build, listener, usernameTokenConcat);
 
                byte[] encodedAuthKey = Base64.encodeBase64(usernameTokenConcat.getBytes());
                connection.setRequestProperty("Authorization", "Basic " + new String(encodedAuthKey));
            }
 
            connection.setDoInput(true);
            connection.setRequestProperty("Accept", "application/json");
            connection.setRequestMethod(requestType);
            // wait up to 5 seconds for the connection to be open
            connection.setConnectTimeout(5000);
            connection.connect();
 
            InputStream is = connection.getInputStream();
 
            BufferedReader rd = new BufferedReader(new InputStreamReader(is));
            String line;
            // String response = "";
            StringBuilder response = new StringBuilder();
 
            while ((line = rd.readLine()) != null) {
                response.append(line);
            }
            rd.close();
 
            // JSONSerializer serializer = new JSONSerializer();
            // need to parse the data we get back into struct
            //listener.getLogger().println("Called URL: '" + urlString +  "', got response: '" + response.toString() + "'");
            if ( response.toString().isEmpty() ) {
                listener.getLogger().println("Remote Jenkins server returned empty response to trigger.");
                return null;
            } else {
                responseObject = (JSONObject) JSONSerializer.toJSON(response.toString());
            }
 
        } catch (IOException e) {
            //If we have ConnectionRetryLimit set to > 0 then retry that many times.
            if ( NumberOfAttempts <= this.getConnectionRetryLimit() ) {
 
                listener.getLogger().println("Connection to remote server failed, waiting for to retry - " + this.pollInterval + " seconds until next attempt.");
                
                // Sleep for 'pollInterval' seconds.
                // Sleep takes miliseconds so need to convert this.pollInterval to milisecopnds (x 1000)
                try {
                    // Could do with a better way of sleeping...
                    Thread.sleep(this.pollInterval * 1000);
                } catch (InterruptedException ex) {
                    this.failBuild(ex, listener);
                }
                
                String strNumberOfRetries = Integer.toString(NumberOfAttempts);
                String strConnectionRetryLimit = Integer.toString(this.getConnectionRetryLimit() );
 
                listener.getLogger().println("Retrying (attempt  " + strNumberOfRetries + " out of " + strConnectionRetryLimit );
                responseObject = sendHTTPCall(urlString, requestType, build, listener, NumberOfAttempts+1);
            }
            // something failed with the connection, so throw an exception to mark the build as failed.
            else {
                this.failBuild(e, listener);
            }
        } catch (MacroEvaluationException e) {
            this.failBuild(e, listener);
        } catch (InterruptedException e) {
            this.failBuild(e, listener);
        } finally {
            // always make sure we close the connection
            if (connection != null) {
                connection.disconnect();
            }
            // and always clear the query string and remove some "global" values
            this.clearQueryString();
            // this.build = null;
            // this.listener = null;
 
        }
        return responseObject;
    }
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