Java How to read last few lines of a File
摘要: In Java, we can use the Apache Commons IO ReversedLinesFileReader to read the last few lines of a File.
In Java, we can use the Apache Commons IO ReversedLinesFileReader to read the last few lines of a File.
pom.xml
<dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.6</version> </dependency>
1. Test Data
A server log file sample
d:\\server.log
2. Read Last Line
2.1 Read the last 3 lines of a file.
TestReadLastLine.java
package com.mkyong.io;
import org.apache.commons.io.input.ReversedLinesFileReader;
import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
public class TestReadLastLine {
public static void main(String[] args) {
List<String> lines = readLastLine(new File("D:\\server.log"), 3);
lines.forEach(x -> System.out.println(x));
public static List<String> readLastLine(File file, int numLastLineToRead) {
List<String> result = new ArrayList<>();
try (ReversedLinesFileReader reader = new ReversedLinesFileReader(file, StandardCharsets.UTF_8)) {
String line = "";
while ((line = reader.readLine()) != null && result.size() < numLastLineToRead) {
result.add(line);
} catch (IOException e) {
e.printStackTrace();
return result;
Output
