StringMatching

import java.io.IOException;
import java.nio.charset.Charset;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.stream.Stream;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableAutoConfiguration
public class StringMatching {
    private static final Logger LOG = LoggerFactory.getLogger(StringMatching.class);

    public void match(String match, String dirPath, String fileNamePrefix) {
        LOG.info("Match=" + match);
        LOG.info("DirPath=" + dirPath);
        LOG.info("FileNamePrefix=" + fileNamePrefix);

        LOG.info("*****************START*****************");

        LOG.info("Threads: " + Runtime.getRuntime().availableProcessors());

        try {
            long start = System.nanoTime();
            final Counter fileCounter = new Counter();
            Files.newDirectoryStream(Paths.get(dirPath), p -> p.getFileName().toString().startsWith(fileNamePrefix) && !Files.isDirectory(p)).
                forEach(filePath -> {
                    LOG.info("Searching in " + filePath + " ...");
                    try (Stream<String> lines = Files.lines(filePath, Charset.defaultCharset())) {
                        lines.filter(line -> line.contains(match)).findAny().
                            ifPresent(matchingLine -> {
                                LOG.info("Found match in file=[" + filePath + "]");
                                fileCounter.add();
                            });
                    } catch (IOException e) {
                        throw new RuntimeException(e);
                    }
                });

            LOG.info("Found " + fileCounter.get() + " files with match");
            long end = System.nanoTime();
            LOG.info("Time: " + (end - start)/1000000 +  " ms");
        } catch (IOException e) {
            throw new RuntimeException(e);
        };

        LOG.info("*****************END*****************");
    }

    private static final class Counter {
        int counter = 0;

        public void add() {
            counter++;
        }

        public int get() {
            return counter;
        }
    }
}