package org.baeldung.java;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Scanner;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.LineIterator;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.base.Charsets;
import com.google.common.io.Files;
public class JavaIoIntegrationTest {
protected final Logger logger = LoggerFactory.getLogger(getClass());
// tests - iterate lines in a file
@Test
public final void givenUsingGuava_whenIteratingAFile_thenCorrect() throws IOException {
final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
// final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
logMemory();
Files.readLines(new File(path), Charsets.UTF_8);
logMemory();
}
@Test
public final void givenUsingCommonsIo_whenIteratingAFileInMemory_thenCorrect() throws IOException {
// final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
logMemory();
FileUtils.readLines(new File(path));
logMemory();
}
@Test
public final void whenStreamingThroughAFile_thenCorrect() throws IOException {
final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
// final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
logMemory();
FileInputStream inputStream = null;
Scanner sc = null;
try {
inputStream = new FileInputStream(path);
sc = new Scanner(inputStream, "UTF-8");
while (sc.hasNextLine()) {
final String line = sc.nextLine();
// System.out.println(line);
}
// note that Scanner suppresses exceptions
if (sc.ioException() != null) {
throw sc.ioException();
}
} finally {
if (inputStream != null) {
inputStream.close();
}
if (sc != null) {
sc.close();
}
}
logMemory();
}
@Test
public final void givenUsingApacheIo_whenStreamingThroughAFile_thenCorrect() throws IOException {
final String path = "G:\\full\\train\\input\\" + "trainDataNegative.csv";
// final String path = "G:\\full\\train\\input\\" + "trainDataPositive.csv";
logMemory();
final LineIterator it = FileUtils.lineIterator(new File(path), "UTF-8");
try {
while (it.hasNext()) {
final String line = it.nextLine();
// do something with line
}
} finally {
LineIterator.closeQuietly(it);
}
logMemory();
}
// utils
private final void logMemory() {
logger.info("Max Memory: {} Mb", Runtime.getRuntime().maxMemory() / 1048576);
logger.info("Total Memory: {} Mb", Runtime.getRuntime().totalMemory() / 1048576);
logger.info("Free Memory: {} Mb", Runtime.getRuntime().freeMemory() / 1048576);
}
}