import java.io.*;
import java.time.LocalDateTime;
import javax.servlet.*;
import javax.servlet.http.*;
public class TimeServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 设置响应内容类型
response.setContentType("text/html;charset=UTF-8");
// 获取当前时间的字符串表示
String time = LocalDateTime.now().toString();
// 输出时间到网页中
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>网页时钟</title>");
out.println("<meta http-equiv=\"refresh\" content=\"1\">");
out.println("</head>");
out.println("<body>");
out.println("<p>当前时间:" + time + "</p>");
out.println("</body>");
out.println("</html>");
}
}
在 web.xml 文件中配置 Servlet 映射
<servlet>
<servlet-name>TimeServlet</servlet-name>
<servlet-class>TimeServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>TimeServlet</servlet-name>
<url-pattern>/time</url-pattern>
</servlet-mapping>
第一种方式: 后端可以写一个接口,前端轮循调用显示时间
第二种: 直接前端(setInterval())每个一秒获取时间,直接显示。