Various Ways to Measure Code Execution Time in Java

In this article, the author discusses several common ways to measure code execution time in Java, starting with the simple use of System.currentTimeMillis() and moving to more precise utilities.

First, Spring's StopWatch class is introduced, with example code showing how to start, stop, and retrieve the total time in milliseconds.

StopWatch stopWatch = new StopWatch();
stopWatch.start();
//doInsert();
stopWatch.stop();
System.out.println(stopWatch.getTotalTimeMillis());

Next, the native System.nanoTime() method is presented, including a code snippet that records start and end timestamps and prints the elapsed nanoseconds.

long startTime = System.nanoTime();
//doInsert();
long endTime = System.nanoTime();
System.out.println(endTime - startTime);

The article also mentions using new Date() to obtain timestamps, with a corresponding example.

Date startDate = new Date();
//doInsert();
Date endDate = new Date();
System.out.println(endDate.getTime() - startDate.getTime());

Although System.currentTimeMillis() is briefly noted, the focus remains on the three methods above.

A brief list of useful StopWatch methods (start, stop, isRunning, getTotalTimeMillis, getTotalTimeSeconds, getLastTaskTimeMillis, getTaskCount, prettyPrint, getTaskInfo) is provided for further exploration.

The author encourages readers to experiment, share thoughts, and join related discussion groups.