建立一個介面：

package my.web;

public interface SpringWeb {
    void config();
}

實現類：

package my;

import my.web.SpringWeb;

public class SpringInit implements SpringWeb {
    @Override
    public void config() {
        System.out.println("大家好");
    }
}

import my.web.SpringWeb;

 
public class SpringWeblnitializer implements SpringWeb {
    @Override
    public void config() {
        System.out.println("你好，哈皮！");
    }
}

建立：MyWebConfig 等同於web.xml

package my.web;

import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.HandlesTypes;
import java.util.Set;


 
// 等同於web.xml檔案
@HandlesTypes({SpringWeb.class})
public class MyWebConfig implements ServletContainerInitializer {
    @Override
    public void onStartup(Set<Class<?>> set, ServletContext servletContext) throws ServletException {
        System.out.println("hello wrold");

        for (Class<?> aclass : set
 
) {
            SpringWeb o = null;
            try{
                o = (SpringWeb) aclass.newInstance();
                o.config();
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            } catch (InstantiationException e) {
                e.printStackTrace();
            }
        }

    }
}

建立一個servlet 繼承於 HttpServlet

package my.web;

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;

@WebServlet("/aaa")
public class MyServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html;charset=utf-8");
        PrintWriter writer = resp.getWriter();
        writer.write("。。。。。");
    }
}

 在src下建立 META-INF 包 

其次在建立一個 services 的包  新增一個filed的檔案

//加上這一句 目的專案在初始化自動找到web.xml檔案
my.web.MyWebConfig

結果：

原始碼地址：https://github.com/nongzihong/servlet_new