How to append content to file in Java

FileWritter, a character stream to write characters to file. By default, it will replace all the existing content with new content, however, when you specified a true (boolean) value as the second argument in FileWritter constructor, it will keep the existing content and append the new content in the end of the file.

package org.best.example.file;
 
import java.io.File;
import java.io.FileWriter;
import java.io.BufferedWriter;
import java.io.IOException;
 
public class AppendToFileExample 
{
    public static void main( String[] args )
    { 
     try{
      String data = " This content will append to the end of the file";
 
      File file =new File("javaio-appendfile.txt");
 
      //if file doesnt exists, then create it
      if(!file.exists()){
       file.createNewFile();
      }
 
      //true = append file
      FileWriter fileWritter = new FileWriter(file.getName(),true);
             BufferedWriter bufferWritter = new BufferedWriter(fileWritter);
             bufferWritter.write(data);
             bufferWritter.close();
 
         System.out.println("Done");
 
     }catch(IOException e){
      e.printStackTrace();
     }
    }
}