SpringMVC 限流的示例代碼

在使用SpringBoot做接口訪問如何做接口的限流，這裡我們可以使用google的Guava包來實現，當然我們也可以自己實現限流，Guava中的限流是久經考驗的我們沒必需重新再去寫一個，如果想了解限流原理的同學可以自己查閱一下相關的資料，本文不作過來說明噢。

使用說明

在項目中引入Guava相關包

http://mvnrepository.com/artifact/com.google.guava/guava/21.0

maven項目

<!-- https://mvnrepository.com/artifact/com.google.guava/guava --><dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>21.0</version></dependency>

gradle項目

// https://mvnrepository.com/artifact/com.google.guava/guavacompile group: 'com.google.guava', name: 'guava', version: '21.0'

寫一個SpringMVC的攔截器

SmoothBurstyInterceptor.java

 import com.google.common.util.concurrent.RateLimiter;import org.springframework.web.servlet.ModelAndView;import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.util.concurrent.TimeUnit;public class SmoothBurstyInterceptor extends HandlerInterceptorAdapter { public enum LimitType { DROP,//丟棄WAIT //等待} /** * 限流器*/ private RateLimiter limiter; /** * 限流方式*/ private LimitType limitType = LimitType.DROP; public SmoothBurstyInterceptor() { this.limiter = RateLimiter.create(10); } /** * @param tps 限流量(每秒處理量) * @param limitType 限流類型:等待/丟棄(達到限流量) */ public SmoothBurstyInterceptor(int tps, SmoothBurstyInterceptor.LimitType limitType) { this.limiter = RateLimiter.create(tps); this.limitType = limitType; } /** * @param permitsPerSecond 每秒新增的令牌數* @param limitType 限流類型:等待/丟棄(達到限流量) */ public SmoothBurstyInterceptor(double permitsPerSecond, SmoothBurstyInterceptor.LimitType limitType) { this.limiter = RateLimiter.create(permitsPerSecond, 1000, TimeUnit.MILLISECONDS); this.limitType = limitType; } @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { if (limitType.equals(LimitType.DROP)) { if (limiter.tryAcquire()) { return super.preHandle(request, response, handler); } } else { limiter.acquire(); return super.preHandle(request, response, handler); } throw new Exception("網絡異常!");//達到限流後，往頁面提示的錯誤信息。 } @Override public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception { super.postHandle(request, response, handler, modelAndView); } @Override public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception { super.afterCompletion(request, response, handler, ex); } public RateLimiter getLimiter() { return limiter; } public void setLimiter(RateLimiter limiter) { this.limiter = limiter; }}

SpringMVC攔截配置

WebConfig.java

 @Componentpublic class WebConfig extends WebMvcConfigurerAdapter { @Override public void addInterceptors(InterceptorRegistry registry) { // 多個攔截器組成一個攔截器鏈registry.addInterceptor(new SmoothBurstyInterceptor(100, SmoothBurstyInterceptor.LimitType.DROP)).addPathPatterns("/**"); //限流可配置為SmoothBurstyInterceptor.LimitType.DROP丟棄請求或者SmoothBurstyInterceptor.LimitType.WAIT等待，100為每秒的速率super.addInterceptors(registry); }}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。