import java.io.File; import java.io.IOException; import java.io.PrintWriter; import jakarta.servlet.ServletException; import jakarta.servlet.annotation.WebServlet; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; @WebServlet("/DirIndex") public class DirIndex extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType( "text/html; charset=UTF-8"); PrintWriter out = response.getWriter(); // ↓適切なパスに変更する String path = getServletContext().getRealPath("/"); File dir = new File(path); // dir にあるファイル名の配列を得る String[] files = dir.list(); out.println(""); out.println("

");

    int i;
    out.printf("%sのファイル一覧%n%n", path);
    for (i = 0; i < files.length; i++) {
        // files の各要素を順に出力
        out.println(files[i]);   
    }

    out.println("

"); out.println(""); out.close(); } }