文本计数器

import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.io.PrintWriter; import java.util.Calendar; import java.util.Date; public class PrintSum { public static void main(String[] args) throws NumberFormatException, IOException { PrintSum current = new PrintSum(); current.setNum(); System.out.println(current.getNum()); } public int getNum() throws IOException { String string = ""; BufferedReader reader = new BufferedReader(new FileReader("sum.txt")); while ((string = reader.readLine()) != null) { return Integer.parseInt(string.trim()); } reader.close(); return 0; } public void setNum() throws IOException { int i = getNum(); i++; PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter( "sum.txt", false))); out.write(String.valueOf(i)); out.close(); } }