A reporter example that shows how to extract logs for each Test Method in TestNG

SampleReporter.java

import java.util.ArrayList;
import java.util.List;
import org.testng.IReporter;
import org.testng.ISuite;
import org.testng.ISuiteResult;
import org.testng.ITestResult;
import org.testng.Reporter;
import org.testng.xml.XmlSuite;

public class SampleReporter implements IReporter {

  @Override
  public void generateReport(List<XmlSuite> xmlSuites, List<ISuite> suites,
      String outputDirectory) {
    suites.forEach(this::generateReport);
  }

  private void generateReport(ISuite suite) {
    suite.getResults().values().forEach(this::generateReport);
  }

  private void generateReport(ISuiteResult suiteResult) {
    List<ITestResult> allResults = new ArrayList<>(
        suiteResult.getTestContext().getPassedTests().getAllResults());
    allResults.addAll(suiteResult.getTestContext().getFailedTests().getAllResults());
    allResults.forEach(this::generateReport);
  }

  private void generateReport(ITestResult testResult) {
    List<String> logs = Reporter.getOutput(testResult);
    logs.forEach(System.out::println);
  }
}