spring boot 如何是自己写的三大组件生效

SpringBoot整合三大组件

最新推荐文章于 2024-05-19 12:31:53 发布

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#java #spring #spring boot

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本文详细介绍了在SpringBoot中如何手动注册自定义的Servlet、Filter和Listener，通过具体代码示例展示了三大组件的集成过程。

在Spring Boot 中因为没有web.xml 所以要想让自己的三大组件生效需要自己手动注册

新建一个配置类或者在已有的配置类中注册

import com.jsen.springboot_web.filter.Myfilter;
import com.jsen.springboot_web.listener.MyListener;
import com.jsen.springboot_web.servlet.MyServlet;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.Arrays;

/**
 * 这是个配置类
 */
@Configuration
public class MyServerConfig {

    //注册三大组件 --注册Servlet
    @Bean
    public ServletRegistrationBean myServlet() {
        return new ServletRegistrationBean(new MyServlet(), "/myServlet");
    }

    //注册三大组件 --注册filter
    @Bean
    public FilterRegistrationBean myFilter() {
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new Myfilter());
        bean.setUrlPatterns(Arrays.asList("/hello", "/jhs"));
        return bean;
    }

    @Bean
    public ServletListenerRegistrationBean myListener() {
        return new ServletListenerRegistrationBean(new MyListener());
    }

}

servlet:

自己的sevlet

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

/**
 * 自己写的   servlet 如何集成到 SpringBoot中
 */
public class MyServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.getWriter().write("欢迎来到 自定义的servlet");
    }
}

Filter

import javax.servlet.*;
import java.io.IOException;

//自己的 filter 过滤器
public class Myfilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
//初始化
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
//过滤请求
        System.out.println("MyFilter process.....");
        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {
//销毁
    }
}

Listener

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class MyListener implements ServletContextListener {
    @Override
    public void contextInitialized(ServletContextEvent sce) {
        System.out.println("contextInitialized ....web应用启动");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        System.out.println("contextDestroyed ....web应用销毁");
    }
}