Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

Sign up
Appearance settings

How to Append Content to File in Java

Ramesh Fadatare edited this page Jul 18, 2018 · 2 revisions

Overview

In Java, you can use FileWriter(file,true) to append new content to the end of a file.

  1. All existing content will be overridden.
new FileWriter(file);
  1. Keep the existing content and append the new content to the end of a file.
new FileWriter(file,true);

FileWriter – Append file example

  1. Let's create a file "sample.txt" under directory "C:/workspace".
  2. Keep some content in file C:/workspace/sample.txt like
There is some content in file
  1. Let's Java example to append new content to the end of a file.
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
 * This Java program demonstrates how to append content to existing file contents.
 * @author javaguides.net
 */
public class AppendFileExample {
	
	private static final Logger LOGGER = LoggerFactory
			.getLogger(AppendFileExample.class);
	
	public static void main(String[] args) {
		appendToExitingFile();
	}
	
	public static void appendToExitingFile(){
		try (Writer writer = new FileWriter("C:/workspace/sample.txt",true);
				BufferedWriter bw = new BufferedWriter(writer)) {
			String content = "append something to existing file\n";
			bw.write(content);
		} catch (IOException e) {
			LOGGER.error(e.getMessage());
		}
	}
}

Output: Let's open the "sample.txt" and verify the content.

There is some content in file append something to existing file

Reference https://docs.oracle.com/javase/8/docs/api/java/io/FileWriter.html https://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html

Tips

User Writer interface as reference type so it provides loose coupling. In future we may use some other Writer classes.

Clone this wiki locally

AltStyle によって変換されたページ (->オリジナル) /