springboot @WebFilter注解过滤器的实现

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@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;
  }
}

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