SpringBoot自定义拦截器

拦截器常用的场景

权限验证，判断用户是否登录，防重复提交等等

自定义拦截器

1. 实现HandlerInterceptor接口

HandlerInterceptor接口

public interface HandlerInterceptor {
	//在业务处理器处理请求之前被调用;预处理，可以进行编码、安全控制、权限校验等处理
	default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
			throws Exception {

		return true;
	}
	//在业务处理器处理请求执行完成后，生成视图之前执行。
	default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
			@Nullable ModelAndView modelAndView) throws Exception {
	}
	//在DispatcherServlet完全处理完请求后被调用
	default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,
			@Nullable Exception ex) throws Exception {
	}

}

实现类
在本篇文章的用法，是对token校验

public class JwtInterceptor implements HandlerInterceptor {
    
    @Autowired
    private JwtUtil jwtUtil;
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String header = request.getHeader("Authorization");
        if (StringUtils.isNotEmpty(header)){
            if (header.startsWith("Bearer ")){
                // 得到token
                final String token = header.substring(7);
                // 对令牌进行验证
                try {
                    Claims claims = jwtUtil.parseJWT(token);
                    String roles = (String) claims.get("roles");
                    if ("admin".equals(roles)) {
                        request.setAttribute("claims_admin", token);
                    }
                    if ("user".equals(roles)) {
                        request.setAttribute("claims_user", token);
                    }
                } catch (Exception e) {
                    throw new RuntimeException("令牌有误!");
                }
            }
        }
        return true;
    }
}

2. 继承WebMvcConfigurationSupport

WebMvcConfigurationSupport

@Configuration
public class InterceptorConfig extends WebMvcConfigurationSupport {

    @Autowired
    private JwtInterceptor jwtInterceptor;
	// 添加拦截器
    @Override
    protected void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(jwtInterceptor)
                .addPathPatterns("/**")
                .excludePathPatterns("/**/login/**");

    }
}