带你读《2022技术人的百宝黑皮书》——一个搞定责任链的注解（9）

/**
* 请求令牌处理类
*/
public class AcquireThrottlerHandler implements MessageThrottlerHandler {
private static final Logger apiThrottlerLog = LoggerFactory.getLogger("api.throttler.log"); @Autowired
private ThrottlerProxy throttlerProxy;
@Autowired
private ThrottlerModeConfiguration throttlerModeConfiguration;
private boolean throttle(AcquireToken acquireToken) {
// 获取限流模式
ThrottlerMode throttlerMode = throttlerModeConfiguration.getThrottlerMode(acquireToken.getAp- pKey(), acquireToken.getThrottleTag());
// 执行限流
return !throttlerProxy.tryAcquireWithAppKey(throttlerMode, acquireToken.getAppKey(), acquireTo- ken.getPermits());
}
@Override
  public boolean throttle(MessageThrottlerToken messageThrottlerToken, MessageThrottlerHandler- Context context) {
  boolean throttled = throttle(new AcquireToken(messageThrottlerToken.getThrottleTag(), message- ThrottlerToken.getAppKey(), messageThrottlerToken.getPermits()));
// 限流日志埋点
if (SendSwitch.THROTTLER_ONLY_WATCH || throttled) {
  log(messageThrottlerToken.getAppKey(), messageThrottlerToken.getPermits(), messageThrot- tlerToken.getThrottleTag(), throttled);
  }
  return throttled;
  }
@Override
  public boolean anyThrottle(List<MessageThrottlerToken> messageThrottlerTokens, MessageThrot- tlerHandlerContext context) {
  return throttle(messageThrottlerTokens, acquireTokens -> acquireTokens.stream().anyMatch (this::throttle)
  );
  }
@Override
  public boolean allThrottle(List<MessageThrottlerToken> messageThrottlerTokens, MessageThrot- tlerHandlerContext messageThrottlerHandlerContext) {
  return throttle(messageThrottlerTokens, acquireTokens -> acquireTokens.stream().allMatch (this::throttle)
  );
  }
  private static boolean throttle(List<MessageThrottlerToken> messageThrottlerTokens, Func- tion<List<AcquireToken>, Boolean> function) {
if (CollectionUtils.isEmpty(messageThrottlerTokens)) {
return false;
  }
List<AcquireToken> acquireTokens = messageThrottlerTokens.stream()
  .collect(Collectors.groupingBy(messageThrottlerToken ->  messageThrottlerToken.getAppKey ()))
.entrySet()
.stream()
.map(messageEntry -> {
String appKey = messageEntry.getKey();
int permits = messageEntry.getValue().stream()
.map(messageThrottlerToken -> messageThrottlerToken.getPermits())
.reduce(Integer::sum).orElse(1);
String throttlerTag = messageEntry.getValue().get(0).getThrottleTag();
return new AcquireToken(throttlerTag, appKey, permits);
}).collect(Collectors.toList()); 
  boolean throttled = function.apply(acquireTokens); 
// 限流日志埋点
if (SendSwitch.THROTTLER_ONLY_WATCH || throttled) {
messageThrottlerTokens.forEach(messageThrottlerToken -> {
  log(messageThrottlerToken.getAppKey(), messageThrottlerToken.getPermits(), messageTh- rottlerToken.getThrottleTag(), throttled);
  });
  }
  return throttled;
  }
private static void log(String appKey, int permits, String throttlerTag, boolean throtted) {
List<String> metrics = new ArrayList<>();
metrics.add(appKey);
metrics.add(String.valueOf(permits));
metrics.add(throttlerTag);
metrics.add(String.valueOf(throtted));
String logContent = StringUtils.join(metrics, "|");
apiThrottlerLog.info(logContent);