何时将访问令牌与刷新令牌交换

由于您有一个现有的令牌管理器,我将向其中添加一些额外的逻辑(Java):

class TokenManager {

  private String accessToken;
  private CompletableFuture<String> accessTokenRefreshComletableFuture;

  public CompletableFuture<String> getAccessToken() {
    if (this.accessToken is expired) {
       // If refreshed accessToken is being requested
       CompletableFuture<String> runningRequestFuture = this.accessTokenRefreshComletableFuture;
       if (runningRequestFuture == null) {
          // For thread safety, this assignment should be synchronized (or made atomic)
          // with the previous reading
          this.accessTokenRefreshComletableFuture = new CompletableFuture<>();
          // Request a fresh access token.
          // When you get a new access token, set the this.accessTokenRefreshComletableFuture 
          // complete and remove its reference from the manager class.
       }
       return runningRequestFuture;
    }
    // Synchronous result
    return CompletableFuture.completedFuture(this.accessToken);
  }
}

管理器不返回访问令牌,而是返回 CompletableFuture (JavaScript中的承诺-异步结果)。如果需要刷新访问令牌,请首先检查 /token 终结点请求已在运行。如果是的话,把它的 CompletableFuture

这样,您将始终拥有有效的访问令牌或单个 完全未来