springBoot中新建拦截器

最近项目中需要将请求中的header中增加几个字段，第一反应就是可不可以用拦截器拦截请求后将字段放进请求头中，经过网上一番学习后发现该方案可行，故将此方法记录下来供大家参考，也算是对自己学习成果的一个沉淀。

• 首先建一个拦截器类

• package com.chwtest.filter;
  
  import java.io.IOException;
  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;
  
  @WebFilter(filterName = "testFilter", urlPatterns = { "/testFilter" })
  public class RequestFilter implements Filter {
  
      @Override
      public void init(FilterConfig filterConfig) throws ServletException {
          Filter.super.init(filterConfig);
      }
  
      @Override
      public void destroy() {
          Filter.super.destroy();
      }
  
      @Override
      public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
              throws IOException, ServletException {
  
          System.out.println("拦截器生效");
          chain.doFilter(request, response);
      }
  
  }

  该类需要一个注解：@WebFilter ，并且需要实现 Filter 并重写doFilter方法

• 在启动类中增加注解：@ServletComponentScan

• package com.chwtest;
  
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.boot.web.servlet.ServletComponentScan;
  
  @SpringBootApplication
  @ServletComponentScan
  @EnableAutoConfiguration
  public class App {
      public static void main(String[] args) {
          SpringApplication.run(App.class, args);
      }
  }

   

• 新建一个controller

• package com.chwtest.controller;
  
  import javax.servlet.http.HttpServletRequest;
  
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.bind.annotation.RestController;
  
  @RestController
  public class Controller {
      @RequestMapping("testFilter")
      public String testFilter(HttpServletRequest request) {        
          return "hello word!";
      }
  
  }

   

• 启动程序
• 

   

   

   

   至此拦截器已建好