应用场景：用户注册，电商秒杀接口,高并发 .... #### 1.创建自定义注解 ``` import java.lang.annotation.*; /** * @author Judge * @date 2020/11/5 14:16 */ @Inherited @Documented @Target({ElementType.FIELD, ElementType.METHOD, ElementType.TYPE}) @Retention(RetentionPolicy.RUNTIME) public @interface AccessLimit { /** * 标识限制次数 * * @return */ int limit() default 5; /** * 标识时间 * * @return */ int sec() default 5; } ``` #### 2.创建拦截器并通过反射对接口的访问进行限制 ``` import com.ccl.coding.sso.annotation.AccessLimit; import com.ccl.coding.sso.exception.AccessLimitException; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.stereotype.Component; import org.springframework.web.method.HandlerMethod; import org.springframework.web.servlet.handler.HandlerInterceptorAdapter; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.lang.reflect.Method; import java.util.concurrent.TimeUnit; /** * 创建拦截器类实现HandlerInterceptor 接口 */ @Slf4j @Component public class AccessLimitInterceptor extends HandlerInterceptorAdapter { @Autowired private RedisTemplate redisTemplate; @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handle) throws Exception { //判断handle是否为方法handle if (handle instanceof HandlerMethod) { //是的话转为HandleMethod HandlerMethod handleMethod = (HandlerMethod) handle; //获取方法 Method method = handleMethod.getMethod(); //判断该方法上是否有自定义注解@AccessLimit if (!method.isAnnotationPresent(AccessLimit.class)) { //不存在该注解则放行 return super.preHandle(request, response, handle); } //获取自定义注解对象 AccessLimit accessLimit = method.getAnnotation(AccessLimit.class); if (accessLimit == null) { //放行 return super.preHandle(request, response, handle); } //获取注解属性值 int limit = accessLimit.limit(); int sec = accessLimit.sec(); //可将用户的id加上 限制每一个用户只能访问几次 String key = request.getRequestURI(); log.info("key : {}", key); //从redis中获取记录 Integer maxLimit = (Integer) redisTemplate.opsForValue().get(key); if (maxLimit == null) { //第一次，计数器设置为1，设置redis过期时间 redisTemplate.opsForValue().set(key, 1, sec, TimeUnit.SECONDS); } else if (maxLimit < limit) { //计数器加1 redisTemplate.opsForValue().set(key, maxLimit + 1, sec, TimeUnit.SECONDS); } else { //BusinessException为自义定异常类 response.setContentType("text/html; charset=utf-8"); // throw new BusinessException("访问频繁,客官休息一会哦！"); // response.getWriter().write(JSON.toJSONString(new ResponseVo(-1, "访问频繁,客官休息一会哦！"))); response.getWriter().write(JSON.toJSONString(new ResponseVo(-1, "访问频繁,客官休息一会哦！"))); return false; } } return super.preHandle(request, response, handle); } } ``` #### 对访问的资源进行拦截 ``` import com.ccl.coding.sso.interceptor.AccessLimitInterceptor; import com.ccl.coding.sso.interceptor.AuthCheckInterceptor; import com.ccl.coding.sso.interceptor.RequestContextInterceptor; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.InterceptorRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; /** * @author CHANG * @date 2019/7/28 11:01 */ @Configuration public class InterceptorConfiguration implements WebMvcConfigurer { @Autowired private AuthCheckInterceptor authCheckInterceptor; @Autowired private AccessLimitInterceptor accessLimitInterceptor; @Override public void addInterceptors(InterceptorRegistry registry) { registry.addInterceptor(new RequestContextInterceptor()).addPathPatterns("/**"); registry.addInterceptor(authCheckInterceptor).addPathPatterns("/**"); registry.addInterceptor(accessLimitInterceptor).addPathPatterns("/**"); } } ``` 自定义异常类： ``` import lombok.Data; /** * 业务系统 RuntimeException * 业务异常， 需要对外抛错。 * 1. 接管异常信息 * 2. 单据信息与后台信息交互 * 3. 业务错误进行回滚 * * @author qingjiaqi * @date 2019-09-10 09:58 */ @Data public class BusinessException extends RuntimeException { public int code; private String message; /** * 默认code */ public BusinessException() { super(); this.code = CommonErrCode.BUSINESS.getCode(); } /** * 默认code码 * * @param message */ public BusinessException(String message) { super(message); this.code = CommonErrCode.BUSINESS.code; this.message = message; } /** * 指定错误码 * * @param code * @param message */ public BusinessException(int code, String message) { super(message); this.code = code; this.message = message; } public BusinessException(CommonErrCode errCode) { super(errCode.getMsg()); this.code = errCode.getCode(); this.message = errCode.getMsg(); } } ``` 异常码： ``` /** * 异常类 * * @author qingjiaqi * @date 2019-09-10 09:41 */ public enum CommonErrCode { NONE(0, "OK"), LOGIN_INVALID(300000, "登录失效"), REPEAT_LOGIN(300001, "您的账号在其他地方登录，如非本人操作，建议修改用户密码！"), UN_LOGIN(300002, "未登陆"), UN_REGISTER(300003, "未注册"), ARGS_INVALID(400000, "请求参数有误"), UNPACK_ERROR(400001, "报文解析失败"), SIGN_INVALID(400010, "验签失败"), DECRYPT_ERROR(400020, "解密失败"), ACCESS_TOKEN_ERROR(400030, "获取 ACESS_TOKEN 失败"), AUTH_TOKEN_INVALID(400300, "访问令牌非法"), NO_PERMISSION(400310, "没有访问权限"), NO_DATA_FOUND(400400, "没有数据"), NETWORK_ERROR(400500, "网络通讯故障"), BUSINESS(400600, "业务处理异常"), BAD_REQUEST(410000, "请求被拒绝"), SERVICE_NOT_EXISTS(420000, "服务不存在"), SERVICE_UNAVAILABLE(420001, "服务不可用"), SERVICE_ALREADY_EXISTS(420002, "服务已存在"), INTERNAL_SERVER_ERROR(500000, "服务器内部错误"), SERVICE_INVOKE_ERROR(500100, "服务调用出错"), DB_ERROR(500200, "数据库错误"), UNKNOW_ERROR(999999, "网络超时或未知异常"), ERROR(999998, "网络超时或未知异常"), AUTHCODE_ERROR(400700, "获取openId失败"); int code; String message; CommonErrCode(int code, String message) { this.code = code; this.message = message; } public int getCode() { return code; } public String getMsg() { return message; } } ```