Java code

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.File;
import java.io.FileWriter;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;

public class dd {


  public void removeLineFromFile(String file, String lineToRemove) {

    try {

      File inFile = new File(file);

      if (!inFile.isFile()) {
        System.out.println("Parameter is not an existing file");
        return;
      }

      //Construct the new file that will later be renamed to the original filename.
      File tempFile = new File(inFile.getAbsolutePath() + ".tmp");

      BufferedReader br = new BufferedReader(new FileReader(file));
      PrintWriter pw = new PrintWriter(new FileWriter(tempFile));

      String line = null;

      //Read from the original file and write to the new
      //unless content matches data to be removed.
      while ((line = br.readLine()) != null) {

        if (!line.trim().equals(lineToRemove)) {

          pw.println(line);
          pw.flush();
        }
      }
      pw.close();
      br.close();

      //Delete the original file
      if (!inFile.delete()) {
        System.out.println("Could not delete file");
        return;
      }

      //Rename the new file to the filename the original file had.
      if (!tempFile.renameTo(inFile))
        System.out.println("Could not rename file");

    }
    catch (FileNotFoundException ex) {
      ex.printStackTrace();
    }
    catch (IOException ex) {
      ex.printStackTrace();
    }
  }

  public static void main(String[] args) {
    dd util = new dd();
    util.removeLineFromFile("test.txt", "");
  }
}