SpringBoot整合JavaWeb

一、SpringBoot整合Servlet的两种方式

1.通过注解扫描完成Servlet组件的注册

编写Servlet

package com.example.demo.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;

/**

 *SpringBoot整合Servlet方式一

 *

 *<servlet>

 *    <servlet-name>FirstServlet</servlet-name>

 *    <servlet-class>com.bjsxt.servlet.FirstServlet</servlet-class>

 *</servlet>

 *

 *<servlet-mapping>

 * <servlet-name>FirstServlet</servlet-name>

 * <url-pattern>/first</url-pattern>

 *</servlet-mapping>

 *

 */

@WebServlet(name="FirstServlet",urlPatterns="/first")

public class FirstServlet extends HttpServlet {

    /**

     *

     */

    private static final long serialVersionUID = 8500147337364528371L;

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        super.doGet(req, resp);

        System.out.println("FirstServlet...");

    }

}

编写启动器类

package com.example.demo;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.boot.web.servlet.ServletComponentScan;

@SpringBootApplication

@ServletComponentScan //在springBoot启动时会扫描@WebServlet，并将该类实例化

public class SpringbootWebApplication {

    public static void main(String[] args) {

        SpringApplication.run(SpringbootWebApplication.class, args);

    }

}

2.通过方法完成Servlet组件的注册

编写Servlet

package com.example.demo.servlet;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

 *SpringBoot整合Servlet方式二

 *

 */

public class SecondServlet extends HttpServlet {

    /**

     *

     */

    private static final long serialVersionUID = -7076398985231616781L;

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        System.out.println("SecondServlet...");

    }

}

编写启动器类

package com.example.demo;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.boot.web.servlet.ServletRegistrationBean;

import org.springframework.context.annotation.Bean;

import com.example.demo.servlet.SecondServlet;

/**

 * SpringBoot整合Servlet方式二

 *

 *

 */

@SpringBootApplication

public class App2 {

    public static void main(String[] args) {

        SpringApplication.run(App2.class, args);

    }

    @Bean

    public ServletRegistrationBean getServletRegistrationBean(){

        ServletRegistrationBean bean = new ServletRegistrationBean(new SecondServlet());

        bean.addUrlMappings("/second");

        return bean;

    }

}

二、SpringBoot整合Filter的两种方式

1.通过注解扫描完成Filter组件的注册

编写Filter

/**

 *SpringBoot整合Filter 方式一

 *<filter>

 *    <filter-name>FirstFilter</filter-name>

 *    <filter-class>com.bjsxt.filter.FirstFilter</filter-class>

 *</filter>

 *<filter-mapping>

 *    <filter-name>FirstFilter</filter-name>

 *    <url-pattern>/first</url-pattern>

 *</filter-mapping>

 */

//@WebFilter(filterName="FirstFilter",urlPatterns={"*.do","*.jsp"})

@WebFilter(filterName="FirstFilter",urlPatterns="/first")

public class FirstFilter implements Filter {

    @Override

    public void destroy() {

        // TODO Auto-generated method stub

    }

    @Override

    public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)

            throws IOException, ServletException {

        System.out.println("进入Filter");

        arg2.doFilter(arg0, arg1);

        System.out.println("离开Filter");

    }

    @Override

    public void init(FilterConfig arg0) throws ServletException {

        // TODO Auto-generated method stub

    }

}

编写启动类

/**

 *SpringBoot整合Filter 方式一

 *

 */

@SpringBootApplication

@ServletComponentScan

public class App3 {

    public static void main(String[] args) {

        SpringApplication.run(App3.class, args);

    }

}

2.通过方法完成Filter组件的注册

编写Filter

/**

 *

 *SpringBoot整合Filter 方式二

 *

 */

public class SecondFilter implements Filter {

    @Override

    public void destroy() {

        // TODO Auto-generated method stub

    }

    @Override

    public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2)

            throws IOException, ServletException {

        System.out.println("进入SecondFilter");

        arg2.doFilter(arg0, arg1);

        System.out.println("离开SecondFilter");

    }

    @Override

    public void init(FilterConfig arg0) throws ServletException {

        // TODO Auto-generated method stub

    }

}

编写启动器类

/**

 * SpringBoot整合Filter方式二

 *

 *

 */

@SpringBootApplication

public class App4 {

    public static void main(String[] args) {

        SpringApplication.run(App4.class, args);

    }/**

     * 注册Filter

     */

    @Bean

    public FilterRegistrationBean getFilterRegistrationBean(){

        FilterRegistrationBean bean = new FilterRegistrationBean(new SecondFilter());

        //bean.addUrlPatterns(new String[]{"*.do","*.jsp"});

        bean.addUrlPatterns("/second");

        return bean;

    }

}

三、SpringBoot整合Listener的两种方式

1.通过注解扫描完成Listener的注册

编写Listener

/**

 * springBoot整合Listener

 *

 *<listener>

 *    <listener-class>com.bjsxt.listener.FirstListener</listener-class>

 *</listener>

 */

@WebListener

public class FirstListener implements ServletContextListener {

    @Override

    public void contextDestroyed(ServletContextEvent arg0) {

        // TODO Auto-generated method stub

    }

    @Override

    public void contextInitialized(ServletContextEvent arg0) {

        System.out.println("Listener...init......");

    }

}

编写启动器

/**

 * springBoot整合Listener方式一

 *

 *

 */

@SpringBootApplication

@ServletComponentScan

public class App5 {

    public static void main(String[] args) {

        SpringApplication.run(App5.class, args);

    }

}

2.  通过方法完成Listener组件注册

编写Listener

/**

 * springBoot整合Listener方式二。

 *

 *

 */

public class SecondListener implements ServletContextListener {

    @Override

    public void contextDestroyed(ServletContextEvent arg0) {

        // TODO Auto-generated method stub

    }

    @Override

    public void contextInitialized(ServletContextEvent arg0) {

        System.out.println("SecondListener..init.....");

    }

}

编写启动器类

/**

 * SpringBoot整合Listener方式二

 *

 *

 */

@SpringBootApplication

public class App6 {

    public static void main(String[] args) {

        SpringApplication.run(App6.class, args);

    }

    /**

     * 注册listener

     */

    @Bean

    public ServletListenerRegistrationBean<SecondListener> getServletListenerRegistrationBean(){

        ServletListenerRegistrationBean<SecondListener> bean= new ServletListenerRegistrationBean<SecondListener>(new SecondListener());

        return bean;

    }

}

四、访问静态资源

1. SpringBoot可在classpath/static的目录下存放静态资源

2. SpringBoot可在ServletContext根目录下存放静态资源

在src/main/webapp  目录名称必须要webapp

五、文件上传

1.编写Controller类

/**

 * SpringBoot文件上传

 *

 *

 */

//@Controller

@RestController //表示该类下的方法的返回值会自动做json格式的转换

public class FileUploadController {

    /*

     * 处理文件上传

     */

    @RequestMapping("/fileUploadController")

    public Map<String, Object> fileUpload(MultipartFile filename)throws Exception{

        System.out.println(filename.getOriginalFilename());

        filename.transferTo(new File("d:/"+filename.getOriginalFilename()));

        Map<String, Object> map = new HashMap<>();

        map.put("msg", "ok");

        return map;

    }

}

2.编写启动器类

/**

 * SpringBoot文件上传

 *

 *

 */

@SpringBootApplication

public class App7 {

    public static void main(String[] args) {

        SpringApplication.run(App7.class, args);

    }

}

3.编写application.properties配置文件，设置上传文件大小的默认值

spring.servlet.multipart.max-file-size=200MB

spring.servlet.multipart.max-request-size=200MB

设置单个上传文件的大小：spring.servlet.multipart.max-file-size=200MB

设置一次请求上传文件的总容量：spring.servlet.multipart.max-request-size=200MB

总结

本篇简单介绍了SpringBoot整合Servlet、Filter、Listener、以及SpringBoot上传文件的方式，下一篇将介绍SpringBoot视图层技术。