Java implements a text file to delete blank lines for example sharing

Java deletes blank lines from text files

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class qukonghang {
 private static String filename1;
 private static String filename2;
 public static void main(String[] args) {
  filename1="file1";
  filename2="file2";
  File file=new File(filename1);
  InputStream is=null;
  BufferedReader br = null;
  String tmp;
  FileWriter writer=null;
  int i=0;
  try {
   is=new BufferedInputStream(new FileInputStream(file));
   br = new BufferedReader(new InputStreamReader(is, "utf-8"));
   writer = new FileWriter(filename2, true);
   while((tmp=br.readLine())!=null){
    if(tmp.equals(""));
    else{
     writer.write(tmp+"n");
     i++;
     System.out.println(i);
    }
   }
   writer.close();
   is.close();
  } catch (IOException e) {
   e.printStackTrace();
  }
 }
}