import java.io.*; import javax.servlet.*; import javax.servlet.http.*; public class Counter extends HttpServlet { @Override public void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException { res.setContentType("text/html; charset=Windows-31J"); PrintWriter out = res.getWriter(); out.println(""); int i; File f = new File(getServletContext().getRealPath("/WEB-INF/counter.txt")); try { BufferedReader fin = new BufferedReader(new FileReader(f)); i = Integer.parseInt(fin.readLine()); fin.close(); // closeを忘れない } catch (FileNotFoundException e) { i = 0; // ファイルがなければ 0に } PrintWriter fout = new PrintWriter(new FileWriter(f)); fout.println(++i); fout.close(); // closeを忘れない out.println("あなたは "+i+"番目の来訪者です。"); out.println(""); out.close(); // closeを忘れない } }