springboot_使用servlet的两种方式

缺乏、安全感 2023-07-07 03:54 23阅读 0赞

**虽然在springboot中我们使用Controller可以应付大部分的需求，但servlet等也是必不可少的。**

**在springboot中使用servlet有两种方式：**

**第一种：**

1.  用注解方式创建一个servlet,并在注解中声明其url
2.  在Application类上添加@ServletComponentScan("com.rong.interceptor.servlet")，该注解里是创建的servlet的路径。

package com.rong.interceptor.servlet;
    
    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;
    
    @WebServlet("/myservlet")
    public class MyServlet extends HttpServlet {
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
           resp.getWriter().write("hello");
        }
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            this.doGet(req,resp);
        }
    }

@SpringBootApplication
    @ServletComponentScan("com.rong.interceptor.servlet")
    public class Application {
    
        public static void main(String[] args) {
            SpringApplication.run(Application.class, args);
        }
    
    }

**第二种（此方式区别在于不使用@ServletComponentScan）：**

1.  仍然要创建一个servlet,与上面一样区别是不用@WebServlet注解。
2.  再创建一个servlet配置类，并在配置类中添加url

package com.rong.interceptor.servlet;
    
    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;
    
    public class MyServlet extends HttpServlet {
        @Override
        protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
           resp.getWriter().write("hello");
        }
        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            this.doGet(req,resp);
        }
    }

package com.rong.interceptor.config;
    
    import com.rong.interceptor.servlet.MyServlet;
    import org.springframework.boot.web.servlet.ServletRegistrationBean;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    @Configuration
    public class ServletConfig {
    
        @Bean
        public ServletRegistrationBean myServletRegistration(){
            ServletRegistrationBean registration = new ServletRegistrationBean(new MyServlet());
            registration.addUrlMappings("/myservlet");
            return registration;
        }
    }