springboot是什么

springboot一种全新的编程规范，其设计目的是用来简化新Spring应用的初始搭建以及开发过程，SpringBoot也是一个服务于框架的框架，服务范围是简化配置文件。

Springboot引入拦截器

自定义的拦截器类 Interceptor

package cn.zytao.taosir.auth.config;import javax.annotation.Resource;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.springframework.web.servlet.HandlerInterceptor;import org.springframework.web.servlet.ModelAndView;public class AuthInterceptor implements HandlerInterceptor{    /**   * 请求处理之后   */  @Override  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)      throws Exception {    // TODO Auto-generated method stub    HandlerInterceptor.super.afterCompletion(request, response, handler, ex);  }  /**   * 请求处理之后调用   */  @Override  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,      ModelAndView modelAndView) throws Exception {    // TODO Auto-generated method stub    HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);  }  /**   * 请求处理之前   */  @Override  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)      throws Exception {    return HandlerInterceptor.super.preHandle(request, response, handler);  }}

将拦截器添加到springmvc配置中，并放行swagger的相关资源

package cn.zytao.taosir.auth.config;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.InterceptorRegistry;import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;@Configurationpublic class SpringMVCConfig extends WebMvcConfigurationSupport{  @Bean  public AuthInterceptor getAuthInterceptor() {    return new AuthInterceptor();  }  @Override  public void addInterceptors(InterceptorRegistry registry) {    registry    .addInterceptor(getAuthInterceptor())    .addPathPatterns("/**")    .excludePathPatterns("/login")    .excludePathPatterns("/swagger-resources/**", "/webjars/**", "/v2/**", "/swagger-ui.html/**");    super.addInterceptors(registry);  }  @Override  protected void addResourceHandlers(ResourceHandlerRegistry registry) {    registry.addResourceHandler("swagger-ui.html")    .addResourceLocations("classpath:/META-INF/resources/");    registry.addResourceHandler("/webjars/**")    .addResourceLocations("classpath:/META-INF/resources/webjars/");    super.addResourceHandlers(registry);  }}

在addInterceptors方法中添加拦截器时，是new的一个拦截器。而并不是引入springBean容器初始化时，已经初始化好了的bean实例，并不是同一个对象，故而访问时肯定是无法引入Interceptor类里面引入的bean实例，可能产生空指针异常。

即无法引入默认注入的Bean，那么我们就自己定义一个Bean，然后在拦截器添加方法内引入这个bean即可，上面主要对此进行了处理。