springboot @WebFilter注解过滤器的实现

@WebFilter注解过滤器

@WebFilter加在过滤器的注解上使用

import lombok.extern.slf4j.Slf4j;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import java.io.IOException;

@WebFilter(urlPatterns = "/*")
@Slf4j
public class WebFilterTest implements Filter {
 @Override
 public void init(FilterConfig filterConfig) throws ServletException {
   log.info("WebFilterTest --- init");
 }

@Override
 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
   log.info("WebFilterTest --- doFilter");
   filterChain.doFilter(servletRequest,servletResponse);
 }

@Override
 public void destroy() {
   log.info("WebFilterTest --- destroy");
 }
}

@WebFilter源码:

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface WebFilter {
 String description() default "";
 /**Filter显示名*/
 String displayName() default "";
 /**配置参数*/
 WebInitParam[] initParams() default {};
 /**Filter名称*/
 String filterName() default "";

String smallIcon() default "";

String largeIcon() default "";
 /**指定对哪些Servlet进行过滤*/
 String[] servletNames() default {};
 /**指定拦截的路径*/
 String[] value() default {};
 /**指定拦截的路径*/
 String[] urlPatterns() default {};
 /**指定Filter对哪种方式的请求进行过滤*/
 DispatcherType[] dispatcherTypes() default {DispatcherType.REQUEST};
 /**指定Filter是否支持异步模式*/
 boolean asyncSupported() default false;
}

在springBoot的启动类中加入注解:

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

@ServletComponentScan

多个@WebFilter注解的过滤器可以配合@Order()注解实现执行过滤的顺序

import org.springframework.core.annotation.Order;

@WebFilter(urlPatterns = "/*")
@Slf4j
@Order(1)
public class WebFilterTest implements Filter {
 @Override
 public void init(FilterConfig filterConfig) throws ServletException {
   log.info("WebFilterTest --- init");
 }

@Override
 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
   log.info("WebFilterTest --- doFilter");
   filterChain.doFilter(servletRequest,servletResponse);
 }

@Override
 public void destroy() {
   log.info("WebFilterTest --- destroy");
 }
}

@WebFilter(urlPatterns = "/*")
@Slf4j
@Order(2)
public class WebFilterTest2 implements Filter {
 @Override
 public void init(FilterConfig filterConfig) throws ServletException {
   log.info("2---WebFilterTest2 --- init");
 }

@Override
 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
   log.info("2 --- WebFilterTest2 --- doFilter");
   filterChain.doFilter(servletRequest,servletResponse);
 }

@Override
 public void destroy() {
   log.info("WebFilterTest2 --- destroy");
 }
}

执行结果

WebFilterTest --- doFilter
2 --- WebFilterTest2 --- doFilter

不使用注解的方式使用过滤器

创建过滤器类

public class WebFilterTest implements Filter {
 @Override
 public void init(FilterConfig filterConfig) throws ServletException {
   log.info("WebFilterTest --- init");
 }

@Override
 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
   log.info("WebFilterTest --- doFilter");
   filterChain.doFilter(servletRequest,servletResponse);
 }

@Override
 public void destroy() {
   log.info("WebFilterTest --- destroy");
 }
}

注册过滤器

@Configuration
public class FilterConfig {

@Bean
 public WebFilterTest webFilterTest(){
   return new WebFilterTest();
 }

@Bean
 public FilterRegistrationBean filterRegist(){
   FilterRegistrationBean frBean = new FilterRegistrationBean();
   frBean.setFilter(webFilterTest());
   frBean.setOrder(1);
   frBean.addUrlPatterns("/*");
   return frBean;
 }
}

多个过滤器注册

再添加一个过滤器:

@Slf4j
public class WebFilterTest2 implements Filter {
 @Override
 public void init(FilterConfig filterConfig) throws ServletException {
   log.info("2---WebFilterTest2 --- init");
 }

@Override
 public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
   log.info("2 --- WebFilterTest2 --- doFilter");
   filterChain.doFilter(servletRequest,servletResponse);
 }

@Override
 public void destroy() {
   log.info("WebFilterTest2 --- destroy");
 }
}

修改配置类:

@Configuration
public class FilterConfig {

@Bean
 public WebFilterTest webFilterTest(){
   return new WebFilterTest();
 }
  @Bean
 public WebFilterTest2 webFilterTest2(){
   return new WebFilterTest2();
 }

@Bean
 public FilterRegistrationBean filterRegist(){
   FilterRegistrationBean frBean = new FilterRegistrationBean();
   frBean.setFilter(webFilterTest());
   frBean.setOrder(1);
   frBean.addUrlPatterns("/*");
   return frBean;
 }
 @Bean
 public FilterRegistrationBean filterRegist2(){
   FilterRegistrationBean frBean = new FilterRegistrationBean();
   frBean.setFilter(webFilterTest2());
   frBean.setOrder(2);
   frBean.addUrlPatterns("/*");
   return frBean;
 }
}

来源：https://segmentfault.com/a/1190000021912102