Javaweb中，使用Servlet编写简单的接口
案例：网页提交用户名和密码信息，后端校验密码长度需在6-12位之间
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后端部分
@WebServlet("/valid") public class SimpleServlet extends HttpServlet{ public void service(HttpServletRequest req, HttpServletResponse resp) throws IOException{ // 获取请求参数 String username = req.getParameter("username"); String password = req.getParameter("password"); // 校验密码长度需在6-12位之间 String result = "NO"; if (password.length() >= 6 && password.length() <= 12) { result = "YES"; } // 将结果写入到响应体中 PrintWriter writer = resp.getWriter(); writer.write(result); } } -
前端部分
<form action="valid" method="post"> <div> <span>用户名：</span> <input type="text" name="username"> </div> <div> <span>密码：</span> <input type="password" name="password"> </div> <button type="submit">提交</button> </form>