springboot集成拦截器

一.首先对HandlerInterceptor进行封装,封装为MappingInterceptor.封装的方法里添加拦截器起作用的路径addPathPatterns(),及需要排除路径的方法excludePathPatterns()

public interface MappingInterceptor extends HandlerInterceptor {
    String[] addPathPatterns();

    String[] excludePathPatterns();

    int order();
}

二.写拦截器,拦截器实现封装好的MappingInterceptor,同时在拦截器上添加@Component,作用是将该拦截器注入到容器中以方便通过@Autowired实现实例注入.

@Component
public class CrossOriginInterceptor implements MappingInterceptor {

    private static final Logger logger= LoggerFactory.getLogger(CrossOriginInterceptor.class);

    @Override
    public String[] addPathPatterns() {
        return new String[]{"/**"};
    }

    @Override
    public String[] excludePathPatterns() {
        return new String[0];
    }

    @Override
    public int order() {
        return 0;
    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        logger.info("允许的头信息"+request.getHeader("Origin"));
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "*");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        //是否允许浏览器携带用户身份信息（cookie）
        response.setHeader("Access-Control-Allow-Credentials","true");
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView 		modelAndView) throws Exception {
    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,
                                Exception ex) throws Exception {

    }
}

三.将拦截器注册到项目中.在类名上添加@Configuration作为配置类在启动的时候实例化好,该类需要实现WebMvcConfigurer接口,然后将写好的拦截器通过 @Autowired注解注入到当前类中,然后重写addInterceptors方法,在方法中注册拦截器,并添加需要拦截的路径及需要排除的路径,注册的顺序代表拦截器执行的顺序.WebConfigurer需要实现 WebMvcConfigurer 这个接口，并实现里面的两个方法。（在老版本的 spring-boot 中使用的是WebMvcConfigurerAdapter，新版本中已过时！！！还有不能通过继承 WebMvcConfigurationSupport 这个类来实现，这样会在某些情况下失效！！！），第二个 addInterceptors 方法用来注册添加拦截器。

@Configuration
public class WebConfigurer implements WebMvcConfigurer {
    @Autowired
    private CrossOriginInterceptor crossOriginInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(crossOriginInterceptor).addPathPatterns(crossOriginInterceptor.addPathPatterns());
    }
}