由于SpringBoot默认是以jar包的形式启动嵌入式servlet容器来启动SpringBoot的web应用,所以没有web.xml文件,那么如何配置Servlet、Filter、Listener呢?
1、自定义Servlet、Filter、Listener容器
2、将各自对应的ServletRegistrationBean、FilterRegistrationBean、ServletListenerRegistrationBean以组件的形式加入到容器中
具体实现如下:
a、自定义servlert类
package com.myself.servlet;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
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("hello MyServlet");
}
}
b、自定义filter类
package com.myself.filter;
import javax.servlet.*;
import java.io.IOException;
public class MyFilter implements Filter {
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
System.out.println("MyFilter process...");
chain.doFilter(request,response);
}
}
c、自定义listener类
package com.myself.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...当前web项目销毁");
}
}
d、将对应的注册类以组件的形式加入到容器中
package com.myself.config;
import com.myself.filter.MyFilter;
import com.myself.listener.MyListener;
import com.myself.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;
@Configuration
public class MyServerConfig {
@Bean
public ServletRegistrationBean myServlet(){
ServletRegistrationBean<MyServlet> myServletServletRegistrationBean = new ServletRegistrationBean<>();
myServletServletRegistrationBean.setServlet(new MyServlet());
myServletServletRegistrationBean.setUrlMappings(Arrays.asList("/myServlet"));
myServletServletRegistrationBean.setLoadOnStartup(1);
return myServletServletRegistrationBean;
}
@Bean
public FilterRegistrationBean myFilter(){
FilterRegistrationBean<MyFilter> myFilterFilterRegistrationBean = new FilterRegistrationBean<>();
myFilterFilterRegistrationBean.setFilter(new MyFilter());
myFilterFilterRegistrationBean.setUrlPatterns(Arrays.asList("/hello","/myFilter"));
return myFilterFilterRegistrationBean;
}
@Bean
public ServletListenerRegistrationBean myListener(){
ServletListenerRegistrationBean<MyListener> myListenerServletListenerRegistrationBean = new ServletListenerRegistrationBean<>();
myListenerServletListenerRegistrationBean.setListener(new MyListener());
return myListenerServletListenerRegistrationBean;
}
}
若有理解不到之处,望指正。