SpringBoot整合Web层技术

目录

• 1 SpringBoot整合Web层技术
  • 1.1 SpringBoot整合Servlet
    • 1.1.1 方式一 通过注解扫描完成Servlet组件的注册
      • 1.1.1.1 创建Servlet
      • 1.1.1.2 修改启动类
    • 1.1.2 方式二 通过方法完成Servlet组件的注册
      • 1.1.2.1 创建Servlet
      • 1.1.2.2 创建Servlet配置类
      • 1.1.2.3 启动类
  • 1.2 SpringBoot整合Filter
    • 1.2.1 方式一 通过注解扫描完成Filter组件注册
      • 1.2.1.1 创建Filter
      • 1.2.1.2 修改启动类
    • 1.2.2 方式二 通过方法完成Filter组件注册
      • 1.2.2.1 创建Filter
      • 1.2.2.2 创建Filter配置类
      • 1.2.1.3 修改启动类
  • 1.3 SpringBoot整合Listener
    • 1.3.1 方式一 通过注解扫描完成Listener组件注册
      • 1.3.1.1 创建Listener
      • 1.3.1.2 修改启动类
    • 1.3.2 方式二 通过方法完成Listener组件注册
      • 1.3.2.1 创建Listener
      • 1.3.2.2 创建配置类
      • 1.3.2.3 修改启动类

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1 SpringBoot整合Web层技术

1.1 SpringBoot整合Servlet

目录结构

1.1.1 方式一 通过注解扫描完成Servlet组件的注册

1.1.1.1 创建Servlet

/**
 * SpringBoot 整合servlet方式一
 */
@WebServlet(name = "FirstServlet" , urlPatterns = {"/first"})
public class FirstServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//        super.doGet(req, resp);
        System.out.println("First Servlet......");
    }
}

需要在Servlet类上加上@WebServlet注解，并指定name属性和urlPatterns属性

1.1.1.2 修改启动类

@SpringBootApplication
@ServletComponentScan //在Spring Boot启动时会扫描@WebServlet注解，并将该类实例化
public class SpringBootWebApplication {

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

}

启动类需要加上ServletComponentScan注解

1.1.2 方式二 通过方法完成Servlet组件的注册

1.1.2.1 创建Servlet

/**
 * SpringBoot 整合servlet方式二
 */
public class SecondServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("Second Servlet......");
    }
}

需要继承HttpServlet

1.1.2.2 创建Servlet配置类

/**
 * 完成Servlet组件的注册
 */
@Configuration
public class ServletConfig {

    /**
     * 容器开始的时候初始化一次
     * @return
     */
    @Bean
    public ServletRegistrationBean getServletRegistrationBean(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new SecondServlet(),"/second");
        bean.addUrlMappings("/second2");
        bean.addUrlMappings("/second3");
        return bean;
    }
}

需要在配置类上加上@Configuration注解，在方法上加上@Bean注解，返回ServletRegistrationBean对象

1.1.2.3 启动类

@SpringBootApplication
public class SpringBootWebApplication {

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

1.2 SpringBoot整合Filter

1.2.1 方式一 通过注解扫描完成Filter组件注册

1.2.1.1 创建Filter

//@WebFilter(filterName = "FirstFilter",urlPatterns = {"*.do","*.jsp"})
@WebFilter(filterName = "FirstFilter",urlPatterns = "/first")
public class FirstFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("进入first Filter..");
        filterChain.doFilter(servletRequest,servletResponse);
        System.out.println("退出first Filter..");
    }

    @Override
    public void destroy() {

    }
}

Filter类需要添加@WebFilter注解，实现Filter接口(javax.servlet.*)

1.2.1.2 修改启动类

@SpringBootApplication
//@ServletComponentScan //在Spring Boot启动时会扫描@WebServlet、@WebFilter注解，并将该类实例化
public class SpringBootWebApplication {

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

}

1.2.2 方式二 通过方法完成Filter组件注册

1.2.2.1 创建Filter

public class SecondFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        System.out.println("进入second Filter..");
        filterChain.doFilter(servletRequest,servletResponse);
        System.out.println("退出second Filter..");
    }

    @Override
    public void destroy() {

    }
}

1.2.2.2 创建Filter配置类

@Configuration
public class FilterConfig {

    @Bean
    public FilterRegistrationBean getFilterRegistration(){
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new SecondFilter());
        filterRegistrationBean.addUrlPatterns("/second");
        return filterRegistrationBean;
    }
}

配置类需要加上@Configuration注解，方法加上@Bean注解，返回FilterRegistrationBean对象

1.2.1.3 修改启动类

@SpringBootApplication
@ServletComponentScan //在Spring Boot启动时会扫描@WebServlet、@WebFilter注解，并将该类实例化
public class SpringBootWebApplication {

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

}

启动类需要加上@ServletComponentScan注解，这样可以扫描@WebFilter注解

1.3 SpringBoot整合Listener

Servlet的8个Listener

1.3.1 方式一 通过注解扫描完成Listener组件注册

1.3.1.1 创建Listener

@WebListener
public class FirstListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("first listener ... init");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        System.out.println("first listener ... destroy");
    }
}

Listener类需要加上@WebListener注解

1.3.1.2 修改启动类

@SpringBootApplication
@ServletComponentScan //在Spring Boot启动时会扫描@WebServlet、@WebFilter、@WebListener注解，并将该类实例化
public class SpringBootWebApplication {

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

1.3.2 方式二 通过方法完成Listener组件注册

1.3.2.1 创建Listener

public class SecondListener implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("second listener ... init");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        System.out.println("second listener ... destroy");
    }
}

1.3.2.2 创建配置类

@Configuration
public class ListenerConfig {

    @Bean
    public ServletListenerRegistrationBean getListener(){
        ServletListenerRegistrationBean bean = new ServletListenerRegistrationBean(new SecondListener());
        return bean;
    }
}

类加上@Configuration注解,方法加上@Bean注解

1.3.2.3 修改启动类

@SpringBootApplication
//@ServletComponentScan //在Spring Boot启动时会扫描@WebServlet、@WebFilter、@WebListener注解，并将该类实例化
public class SpringBootWebApplication {

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

}