Spring Boot (教程七： servlet)

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 */@SpringBootApplicationpublic 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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