Record a transaction for custom implementations for AEM Forms on OSGi

import com.adobe.aem.transaction.core.ITransactionRecorder;
import com.adobe.aem.transaction.core.model.TransactionRecord;
import com.adobe.aem.transaction.core.exception.TransactionException;
import com.adobe.aem.transaction.core.FormsTransactionConstants;

@Reference
private ITransactionRecorder transactionRecorder;

doPost (SlingHttpServletRequest request, SlingHttpServletResponse response) {
    transactionRecorder.startContext();
    TransactionRecord txRecord = extractTxRecordFromRequest(request); //extract transaction relevant data from request
    try {
        bool success = doBillableWork();
        if (success) {
            transactionRecorder.recordTransaction(txRecord);
        }
    } catch (Exception e) {
        //exception handling
    } finally {
        transactionRecorder.endContext();
    }
}

//Here, it is assumed that txInfo is passed in Stringified json form in the ajax call (in data parameter). You can pass txInfo from client in any way that you find suitable.
private TransactionRecord extractTxRecordFromRequest(SlingHttpServletRequest request) {
    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(request.getInputStream()));
    Map<String, Object> txDataMap = new HashMap<String, Object>();
    String txData = bufferedReader.readLine();
    JSONObject txInfo= new JSONObject(txData );
    try {
        String resourceType= txInfo.getString("resourceType");
        String transactionType = txInfo.getString("transactionType");
        Integer transactionCount = (Integer)txInfo.get("transactionCount");
        //Extract all the relevant tx record attributes similarly and pass them in Transaction Record constructor as per the java doc}
        return new TransactionRecord(transactionCount, transactionType, resourceType, ..);
    } catch (JSONException e) {
        //exception handling
    } finally {
        bufferedReader.close();
    }
}