How to add a new line of text to an existing file in Java?

java file-io text-processing
CompilingCyborg picture CompilingCyborg · Jan 6, 2011 · Viewed 265.4k times · Source

I would like to append a new line to an existing file without erasing the current information of that file. In short, here is the methodology that I am using the current time: 

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.Writer;

Writer output;
output = new BufferedWriter(new FileWriter(my_file_name));  //clears file every time
output.append("New Line!");
output.close();

The problem with the above lines is simply they are erasing all the contents of my existing file then adding the new line text.

I want to append some text at the end of the contents of a file without erasing or replacing anything.

Answer

Mario F picture Mario F · Jan 6, 2011

you have to open the file in append mode, which can be achieved by using the FileWriter(String fileName, boolean append) constructor.

output = new BufferedWriter(new FileWriter(my_file_name, true));

should do the trick

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