GitHub 地址：

https://github.com/asd821300801/Spring-Boot.git

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Spring Boot 中使用Servlet

通过代码注册Servlet

需要在SpringbootHelloApplication里注册Servlet

@Bean
    public ServletRegistrationBean servletRegistrationBean() {
        return new ServletRegistrationBean(new Servlet1(),"/servlet/*");// ServletName默认值为首字母小写，即servlet
    }

完整代码

• SpringbootHelloApplication.java

package com;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;

import com.example.servlet.Servlet1;
/**
 * Spring Boot 教程一
 * Spring Boot 入门
 * @author LingDu
 */
@SpringBootApplication
public class SpringbootHelloApplication {

    @Bean
    public ServletRegistrationBean servletRegistrationBean() {
        return new ServletRegistrationBean(new Servlet1(),"/servlet/*");// ServletName默认值为首字母小写，即servlet
    }

    public static void main(String[] args) {
        SpringApplication.run(SpringbootHelloApplication.class, args);
    }
}

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在src下创建com.example.servlet包

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• Servlet1.java

package com.example.servlet;

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




/**
 *  通过代码注册Servlet
 * 
 *  1、创建Servlet1.java 继承 HttpServlet 实现 doPost() , doGet()方法
 *  2、在SpringbootHelloApplication.java文件中添加
 * 
 *  @Bean
 *  public ServletRegistrationBean servletRegistrationBean() {
 *     return new ServletRegistrationBean(new Servlet1(),"/servlet/*");// ServletName默认值为首字母小写，即servlet
 *  }
 * 
 * 
 * @author LingDu
 */
public class Servlet1 extends HttpServlet{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    @Override
    public void init() throws ServletException {
        System.out.println("Servlet初始化");
        super.init();
    }
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("-----------> doGet()");
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("-----------> doPost()");
        resp.setContentType("text/html");  
        String id = req.getParameter("id");
        if(id != null && !id.equals("")){
            resp.getWriter().append("-----------> doPost()  id=" + id);
            return;
        }
        resp.getWriter().append("-----------> doPost()");
    }
}

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http://localhost:8080/servlet/servlet?id=1

http://localhost:8080/servlet/

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使用注解的方式注册servlet

使用注解方式注册Servlet需要在SpringbootHelloApplication里添加@ServletComponentScan注解

完整代码

• SpringbootHelloApplication .java

package com;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.ServletComponentScan;
/**
 * Spring Boot 教程一
 * Spring Boot 入门
 * @author LingDu
 */
@SpringBootApplication
@ServletComponentScan //使用注解的方式注册servlet需要在SpringbootHelloApplication.java中添加@ServletComponentScan注解
public class SpringbootHelloApplication {   
    public static void main(String[] args) {
        SpringApplication.run(SpringbootHelloApplication.class, args);
    }
}

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• servlet2.java

package com.example.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 使用注解注册Servlet
 * 
 * 
 * 
 * @author LingDu
 */

//不指定name的情况下，name默认值为类全路径，即org.springboot.sample.servlet.MyServlet2
@WebServlet(urlPatterns="/servlet/servlet2", description="Servlet的说明") 
public class Servlet2 extends HttpServlet {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    @Override
    public void init() throws ServletException {
        System.out.println("Servlet初始化");
        super.init();
    }
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("-----------> doGet()");
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("-----------> doPost()");
        resp.setContentType("text/html");  
        String id = req.getParameter("id");
        if(id != null && !id.equals("")){
            resp.getWriter().append("-----------> doPost()  id=" + id);
            return;
        }
        resp.getWriter().append("-----------> doPost()");
    }
}

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http://localhost:8080/servlet/servlet2?id=1

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修改DispatcherServlet默认配置

在SpringbootHelloApplication .java中添加ServletRegistrationBean

/**
     * 修改DispatcherServlet默认配置
     *
     * @param dispatcherServlet
     * @author LingDu
     */
    @Bean
    public ServletRegistrationBean dispatcherRegistration(DispatcherServlet dispatcherServlet) {
        ServletRegistrationBean registration = new ServletRegistrationBean(dispatcherServlet);
        registration.getUrlMappings().clear();
        registration.addUrlMappings("*.action"); //只有*.action 的请求能通过
        registration.addUrlMappings("*.json");
        return registration;
    }

将@WebServlet访问路径添加上.action

@WebServlet(urlPatterns="/servlet/servlet2.action", description="通过注解注册") 

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访问：

http://localhost:8080/servlet/servlet2.action

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