Java Program to Append Text to an Existing File

In this java tutorial, you will learn about how to append data to an existing text file from a Java program. This means you can write new content at the end of the file. One of the common examples of appending text to file is logging.

We can add a string to an existing file in Java by using FileWriter, which offers the ability to open a file in append mode. The FileWriter class in Java is used to save character-oriented data to a file. It can be used for the efficient writing of single characters, arrays, and strings in a file.

Here are the steps to append data to an existing file.

• Create a File object by passsing the path of the existing text file.


• Create an instance of FileWriter object by passing absolute path of existing file and a true boolean value to represent append mode.


• Write the text data to the file using the write() method of FileWriter object.

import java.io.File;
import java.io.FileWriter;

public class AppendDataInFile {
  public static void main(String args[]) throws Exception {
    String data = "Sample string to append";
    File existingFile = new File("techcrashcourse.txt");

    if(!existingFile.exists()) {
      existingFile.createNewFile();
    }

    FileWriter fileWritter = new FileWriter(
            existingFile.getAbsolutePath(),true);
    fileWritter.write(data);
    fileWritter.close();

    System.out.println("Append Complete");
  }
}

Output

Append Complete

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