I need to optimize a java application. It makes some 3rd party calls. I need some good tool to accurately measure the time taken by individual api calls. To give an idea of complexity- the application takes a data source file containing 10 lakh rows, and it takes around one hour to complete the processing. As a part of processing , it makes some 3rd party calls (including some network calls). I need to identify which calls are taking more time then others, and based on that, find out a way to optimize the application. Any suggestions would be appreciated.