解释如下代码 if (emailConfigList.size() == 0) return 0; int requestCount = (emailConfigList.size() + EACH_THREAD_USER_SIZE - 1) / EACH_THREAD_USER_SIZE; ListeningExecutorService executorService = MoreExecutors.listeningDecorator(threadPoolTaskExecutor.getThreadPoolExecutor()); List<ListenableFuture<Integer>> futureList = new ArrayList<>(); for (int i = 0; i < requestCount; i++) { int current = i; futureList.add( executorService.submit(() -> { List<EmailConfig> temp; int start = current * EACH_THREAD_USER_SIZE; int end; if (current < requestCount - 1) { end = (current + 1) * EACH_THREAD_USER_SIZE; } else { end = emailConfigList.size(); } logger.info("执行用户index从:"+start+"到"+(end - 1)); temp = emailConfigList.subList(start, end); return executeForManyUser(temp, now); }) ); }
时间: 2023-06-05 08:04:19 浏览: 78
这段代码的作用是根据邮件配置列表的大小,将配置均分到多个线程中进行处理。其中,变量EACH_THREAD_USER_SIZE是每个线程处理的配置数量。通过线程池的方式,将处理结果封装成ListenableFuture对象进行返回。
相关问题
给出Java编写熔断和限流的代码
以下是Java编写熔断和限流的示例代码:
熔断:
```
public class CircuitBreaker {
private int failureThreshold;
private int resetTimeout;
private long lastFailureTime;
private int failureCount;
public CircuitBreaker(int failureThreshold, int resetTimeout) {
this.failureThreshold = failureThreshold;
this.resetTimeout = resetTimeout;
this.lastFailureTime = ;
this.failureCount = ;
}
public boolean allowRequest() {
if (failureCount >= failureThreshold) {
long now = System.currentTimeMillis();
if (now - lastFailureTime >= resetTimeout) {
failureCount = ;
} else {
return false;
}
}
return true;
}
public void markSuccess() {
failureCount = ;
}
public void markFailure() {
failureCount++;
lastFailureTime = System.currentTimeMillis();
}
}
```
限流:
```
public class RateLimiter {
private int maxRequests;
private int requestCount;
private long intervalStart;
public RateLimiter(int maxRequests) {
this.maxRequests = maxRequests;
this.requestCount = ;
this.intervalStart = System.currentTimeMillis();
}
public synchronized boolean allowRequest() {
long now = System.currentTimeMillis();
if (now - intervalStart >= 100) {
requestCount = ;
intervalStart = now;
}
if (requestCount >= maxRequests) {
return false;
}
requestCount++;
return true;
}
}
```
java代码如何限制阿里云的client的请求频率具体的java代码实现
您好,以下是一个简单的Java代码示例,演示如何实现请求频率限制:
```java
import com.aliyun.sdk.openservices.ClientException;
import com.aliyun.sdk.openservices.ecs.model.DescribeInstancesRequest;
import com.aliyun.sdk.openservices.ecs.model.DescribeInstancesResponse;
import com.aliyun.sdk.openservices.ecs.model.Instance;
import com.aliyun.sdk.openservices.ecs.model.InstanceStatus;
import java.util.ArrayList;
import java.util.List;
public class AliyunClient {
private static final int REQUEST_LIMIT = 100;
private int requestCount = 0;
private final String accessKeyId;
private final String accessKeySecret;
public AliyunClient(String accessKeyId, String accessKeySecret) {
this.accessKeyId = accessKeyId;
this.accessKeySecret = accessKeySecret;
}
public List<Instance> getInstances() throws ClientException {
if (requestCount >= REQUEST_LIMIT) {
throw new RuntimeException("Request limit has been reached");
}
requestCount++;
DescribeInstancesRequest request = new DescribeInstancesRequest();
DescribeInstancesResponse response = getClient().getAcsResponse(request);
List<Instance> instances = new ArrayList<>();
for (InstanceStatus status : response.getInstanceStatuses()) {
instances.add(status.getInstance());
}
return instances;
}
private EcsClient getClient() {
DefaultProfile profile = DefaultProfile.getProfile(
"cn-hangzhou", accessKeyId, accessKeySecret);
return new EcsClient(profile);
}
}
```
在这个代码示例中,我们首先定义了一个请求频率限制的常量,即 `REQUEST_LIMIT`,其值为 100。我们还定义了一个 `requestCount` 变量,用于跟踪当前已发起的请求次数。
在 `getInstances` 方法中,我们首先检查当前请求次数是否超过限制,如果超过限制,则抛出一个异常。否则,我们向阿里云 API 发起一个 `DescribeInstances` 请求,获取当前的实例列表,并返回结果。
请注意,在真正的应用程序中,我们需要更精细地控制请求频率,以避免请求过于频繁而被阿里云 API 列入黑名单。这超出了本文的范围,如果您需要更多关于请求频率限制的信息,请查看阿里云 API 的文档。