SpringBoot 注册自己的Servlet（三种方式）

方法1:使用servlet3.0规范提供的注解方式注册

@WebServlet

Servlet

1,声明servlet及映射

com/bjpowernode/springbootservlet01/servlet
MyServlet.java

package com.bjpowernode.springbootservlet01.servlet;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebListener;
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(name="MyServlet",urlPatterns = "/myServlet")
public class MyServlet extends HttpServlet {

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doPost(req,resp);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        PrintWriter writer = resp.getWriter();
        writer.println("This is my servlet");
    }
}

2，加上@ServletComponentScan 才会扫描加了这个注解

运行结果

方法2：使用springboot提供的注册

Servlet

com/bjpowernode/springbootservlet02/servlet
BeanServletTest.java

package com.bjpowernode.springbootservlet02.servlet;

import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.stereotype.Component;

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

@Component
public class BeanServletTest extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doPost(req, resp);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        PrintWriter writer = resp.getWriter();
        writer.println("hello this is servlet");
    }
}

配置类

com/bjpowernode/springbootservlet02/config
MyWebMvcConfigurer.java

package com.bjpowernode.springbootservlet02.config;

import com.bjpowernode.springbootservlet02.servlet.BeanServletTest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import javax.servlet.ServletRegistration;

@Configuration
public class MyWebMvcConfigurer implements WebMvcConfigurer {

    @Autowired
    private BeanServletTest beanServletTest;

    @Bean
    public ServletRegistrationBean myServlet(){
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean();
//        servletRegistrationBean.setServlet(new BeanServletTest());
        servletRegistrationBean.setServlet(beanServletTest);
        servletRegistrationBean.setName("beanServlet");
        servletRegistrationBean.addUrlMappings("/beanServlet");
        return servletRegistrationBean;
    }

}

运行结果

方法3：动态注册：

Servlet类

package com.bjpowernode.springbootservlet03.servlet;

import javax.servlet.ServletException;
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 MyServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        super.doPost(req, resp);
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        PrintWriter writer = resp.getWriter();
        writer.println("This is my servlet");
    }
}

配置类

package com.bjpowernode.springbootservlet03.config;

import com.bjpowernode.springbootservlet03.servlet.MyServlet;
import org.springframework.boot.web.servlet.ServletContextInitializer;
import org.springframework.stereotype.Component;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import javax.servlet.annotation.WebServlet;

@Component
public class MyServletConfig implements ServletContextInitializer {
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        ServletRegistration.Dynamic myServlet = servletContext.addServlet("MyServlet", MyServlet.class);
        myServlet.addMapping("/myServlet");
    }
}

运行结果