java_ci/src/main/java/controller/HelloWorld.java

package controller;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

public class HelloWorld  extends HttpServlet {

    private String message;

    @Override
    public void init() throws ServletException {
        message = "Hello world, this message is from servlet! 2022-10-17 20:20";
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //设置响应内容类型
        resp.setContentType("text/html");

        //设置逻辑实现
        PrintWriter out = resp.getWriter();
        out.println("<h1>" + message + "</h1>");
    }

    @Override
    public void destroy() {
        super.destroy();
    }

}