本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。 # 使用 CloudWatch 本節提供使用 適用於 Java 的 AWS SDK 2.x 編寫 [Amazon CloudWatch](https://docs.aws.amazon.com//AmazonCloudWatch/latest/monitoring/WhatIsCloudWatch.html) 程式的範例。 Amazon CloudWatch AWS 會即時監控您的 Amazon Web Services (AWS) 資源和您在 上執行的應用程式。您可以使用 CloudWatch 收集和追蹤指標，這些是您可以針對資源和應用程式測量的變數。 CloudWatch alarms 會根據您定義的規則傳送通知或自動變更您正在監控的資源。 下列範例僅包含示範每個技術所需的程式碼。[GitHub 上提供完整程式碼範例](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2)。您可以從那裡下載單一原始檔案或將儲存庫複製到本機，以取得建置和執行的所有範例。 **Topics** + [從 取得指標 CloudWatch](examples-cloudwatch-get-metrics.md) + [將自訂指標資料發佈至 CloudWatch](examples-cloudwatch-publish-custom-metrics.md) + [使用 CloudWatch 警示](examples-cloudwatch-create-alarms.md) + [使用 Amazon CloudWatch Events](examples-cloudwatch-send-events.md) # 從 取得指標 CloudWatch ## 列出指標 若要列出 CloudWatch 指標，請建立 [ListMetricsRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/ListMetricsRequest.html) 並呼叫 CloudWatchClient 的 `listMetrics`方法。您可以使用 `ListMetricsRequest` 來根據命名空間、指標名稱或維度，篩選傳回的指標。 **注意** 您可以在 Amazon CloudWatch 《 使用者指南》的指標和維度參考中找到 AWS 服務發佈的指標和維度清單。 [Amazon CloudWatch](https://docs.aws.amazon.com//AmazonCloudWatch/latest/monitoring/aws-services-cloudwatch-metrics.html) **匯入** ``` import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.cloudwatch.CloudWatchClient; import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatch.model.ListMetricsRequest; import software.amazon.awssdk.services.cloudwatch.model.ListMetricsResponse; import software.amazon.awssdk.services.cloudwatch.model.Metric; ``` **Code** ``` public static void listMets( CloudWatchClient cw, String namespace) { boolean done = false; String nextToken = null; try { while(!done) { ListMetricsResponse response; if (nextToken == null) { ListMetricsRequest request = ListMetricsRequest.builder() .namespace(namespace) .build(); response = cw.listMetrics(request); } else { ListMetricsRequest request = ListMetricsRequest.builder() .namespace(namespace) .nextToken(nextToken) .build(); response = cw.listMetrics(request); } for (Metric metric : response.metrics()) { System.out.printf( "Retrieved metric %s", metric.metricName()); System.out.println(); } if(response.nextToken() == null) { done = true; } else { nextToken = response.nextToken(); } } } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } } ``` 透過呼叫其 [ 方法，指標會在 ](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/ListMetricsResponse.html)ListMetricsResponse`getMetrics` 中傳回。 結果可能會*分頁*。若要擷取下一批次結果，請在回應物件上呼叫 `nextToken`，並使用字符值來建置新的請求物件。然後以新的請求再次呼叫 `listMetrics` 方法。 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/f4eaf2b2971805cfb2b87a8e5ab408f83169432e/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/ListMetrics.java)。 ## 其他資訊 + Amazon CloudWatch API 參考中的 [ListMetrics](https://docs.aws.amazon.com//AmazonCloudWatch/latest/APIReference/API_ListMetrics.html) # 將自訂指標資料發佈至 CloudWatch 許多 AWS 服務會在以「`AWS`」開頭的命名空間中發佈[自己的指標](https://docs.aws.amazon.com//AmazonCloudWatch/latest/monitoring/aws-services-cloudwatch-metrics.html)。您也可以使用自己的命名空間 （只要不是以「`AWS`」開頭） 來發佈自訂指標資料。 ## 發佈自訂指標資料 若要發佈您自己的指標資料，請使用 [PutMetricDataRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/PutMetricDataRequest.html) 呼叫 CloudWatchClient 的 `putMetricData`方法。`PutMetricDataRequest` 必須在 [MetricDatum](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/MetricDatum.html) 物件中包含用於資料的自訂命名空間，以及資料點本身的相關資訊。 **注意** 您無法指定開頭為 " `AWS` " 的命名空間。以「`AWS`」開頭的命名空間保留供 Amazon Web Services 產品使用。 **匯入** ``` import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.cloudwatch.CloudWatchClient; import software.amazon.awssdk.services.cloudwatch.model.Dimension; import software.amazon.awssdk.services.cloudwatch.model.MetricDatum; import software.amazon.awssdk.services.cloudwatch.model.StandardUnit; import software.amazon.awssdk.services.cloudwatch.model.PutMetricDataRequest; import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import java.time.Instant; import java.time.ZoneOffset; import java.time.ZonedDateTime; import java.time.format.DateTimeFormatter; ``` **Code** ``` public static void putMetData(CloudWatchClient cw, Double dataPoint ) { try { Dimension dimension = Dimension.builder() .name("UNIQUE_PAGES") .value("URLS") .build(); // Set an Instant object String time = ZonedDateTime.now( ZoneOffset.UTC ).format( DateTimeFormatter.ISO_INSTANT ); Instant instant = Instant.parse(time); MetricDatum datum = MetricDatum.builder() .metricName("PAGES_VISITED") .unit(StandardUnit.NONE) .value(dataPoint) .timestamp(instant) .dimensions(dimension).build(); PutMetricDataRequest request = PutMetricDataRequest.builder() .namespace("SITE/TRAFFIC") .metricData(datum).build(); cw.putMetricData(request); } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } System.out.printf("Successfully put data point %f", dataPoint); } ``` 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/f4eaf2b2971805cfb2b87a8e5ab408f83169432e/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/PutMetricData.java)。 ## 其他資訊 + Amazon CloudWatch 《 使用者指南》中的[使用 Amazon CloudWatch 指標](https://docs.aws.amazon.com//AmazonCloudWatch/latest/monitoring/working_with_metrics.html)。 + Amazon CloudWatch 《 使用者指南[AWS 》中的命名空間](https://docs.aws.amazon.com//AmazonCloudWatch/latest/monitoring/aws-services-cloudwatch-metrics.html)。 + Amazon CloudWatch API 參考中的 [PutMetricData](https://docs.aws.amazon.com//AmazonCloudWatch/latest/APIReference/API_PutMetricData.html)。 # 使用 CloudWatch 警示 ## 建立警示 若要根據 CloudWatch 指標建立警示，請呼叫 CloudWatchClient 的 `putMetricAlarm`方法，並將 [PutMetricAlarmRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/PutMetricAlarmRequest.html) 填入警示條件。 **匯入** ``` import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.cloudwatch.CloudWatchClient; import software.amazon.awssdk.services.cloudwatch.model.Dimension; import software.amazon.awssdk.services.cloudwatch.model.PutMetricAlarmRequest; import software.amazon.awssdk.services.cloudwatch.model.ComparisonOperator; import software.amazon.awssdk.services.cloudwatch.model.Statistic; import software.amazon.awssdk.services.cloudwatch.model.StandardUnit; import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; ``` **Code** ``` public static void putMetricAlarm(CloudWatchClient cw, String alarmName, String instanceId) { try { Dimension dimension = Dimension.builder() .name("InstanceId") .value(instanceId).build(); PutMetricAlarmRequest request = PutMetricAlarmRequest.builder() .alarmName(alarmName) .comparisonOperator( ComparisonOperator.GREATER_THAN_THRESHOLD) .evaluationPeriods(1) .metricName("CPUUtilization") .namespace("AWS/EC2") .period(60) .statistic(Statistic.AVERAGE) .threshold(70.0) .actionsEnabled(false) .alarmDescription( "Alarm when server CPU utilization exceeds 70%") .unit(StandardUnit.SECONDS) .dimensions(dimension) .build(); cw.putMetricAlarm(request); System.out.printf( "Successfully created alarm with name %s", alarmName); } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } } ``` 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/f4eaf2b2971805cfb2b87a8e5ab408f83169432e/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/PutMetricAlarm.java)。 ## 列出警示 若要列出您已建立的 CloudWatch 警示，請使用 [DescribeAlarmsRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/DescribeAlarmsRequest.html) 呼叫 CloudWatchClient 的 `describeAlarms`方法，以用於設定結果的選項。 **匯入** ``` import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.cloudwatch.CloudWatchClient; import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatch.model.DescribeAlarmsRequest; import software.amazon.awssdk.services.cloudwatch.model.DescribeAlarmsResponse; import software.amazon.awssdk.services.cloudwatch.model.MetricAlarm; ``` **Code** ``` public static void desCWAlarms( CloudWatchClient cw) { try { boolean done = false; String newToken = null; while(!done) { DescribeAlarmsResponse response; if (newToken == null) { DescribeAlarmsRequest request = DescribeAlarmsRequest.builder().build(); response = cw.describeAlarms(request); } else { DescribeAlarmsRequest request = DescribeAlarmsRequest.builder() .nextToken(newToken) .build(); response = cw.describeAlarms(request); } for(MetricAlarm alarm : response.metricAlarms()) { System.out.printf("\n Retrieved alarm %s", alarm.alarmName()); } if(response.nextToken() == null) { done = true; } else { newToken = response.nextToken(); } } } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } System.out.printf("Done"); } ``` 您可以透過在 `describeAlarms` 傳回的 [DescribeAlarmsResponse](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/DescribeAlarmsResponse.html) 上呼叫 `MetricAlarms`，來取得警示清單。 結果可能會*分頁*。若要擷取下一批次結果，請在回應物件上呼叫 `nextToken`，並使用字符值來建置新的請求物件。然後以新的請求再次呼叫 `describeAlarms` 方法。 **注意** 您也可以使用 CloudWatchClient 的 `describeAlarmsForMetric`方法擷取特定指標的警示。其用法類似於 `describeAlarms`。 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/f4eaf2b2971805cfb2b87a8e5ab408f83169432e/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/DescribeAlarms.java)。 ## 刪除警示 若要刪除 CloudWatch 警示，請使用 [DeleteAlarmsRequest](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/model/DeleteAlarmsRequest.html) 呼叫 CloudWatchClient 的 `deleteAlarms`方法，其中包含一或多個您要刪除的警示名稱。 **匯入** ``` import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.cloudwatch.CloudWatchClient; import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatch.model.DeleteAlarmsRequest; ``` **Code** ``` public static void deleteCWAlarm(CloudWatchClient cw, String alarmName) { try { DeleteAlarmsRequest request = DeleteAlarmsRequest.builder() .alarmNames(alarmName) .build(); cw.deleteAlarms(request); System.out.printf("Successfully deleted alarm %s", alarmName); } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } } ``` 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/f4eaf2b2971805cfb2b87a8e5ab408f83169432e/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/DeleteAlarm.java)。 ## 其他資訊 + Amazon CloudWatch 《 使用者指南》中的[使用 Amazon CloudWatch 警示](https://docs.aws.amazon.com//AmazonCloudWatch/latest/monitoring/AlarmThatSendsEmail.html) + Amazon CloudWatch API 參考中的 [PutMetricAlarm](https://docs.aws.amazon.com//AmazonCloudWatch/latest/APIReference/API_PutMetricAlarm.html) + Amazon CloudWatch API 參考中的 [DescribeAlarms](https://docs.aws.amazon.com//AmazonCloudWatch/latest/APIReference/API_DescribeAlarms.html) + Amazon CloudWatch API 參考中的 [DeleteAlarms](https://docs.aws.amazon.com//AmazonCloudWatch/latest/APIReference/API_DeleteAlarms.html) # 使用 Amazon CloudWatch Events CloudWatch Events 提供近乎即時的系統事件串流，描述 Amazon EC2 執行個體、 Lambda 函數、 Kinesis 串流、 Amazon ECS 任務、 Step Functions 狀態機器、 Amazon SNS 主題、 Amazon SQS 佇列或內建目標 AWS 的資源變更。您可以使用簡單的規則，來比對事件，並將這些事件轉傳到一或多個目標函數或串流。 Amazon EventBridge 是 CloudWatch Events 的[演變](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-cwe-now-eb.html)。這兩個服務都使用相同的 API，因此您可以繼續使用 SDK 提供的 [CloudWatch Events 用戶端](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatch/CloudWatchClient.html)，或遷移至適用於 Java 的 SDK [EventBridge 用戶端](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/eventbridge/EventBridgeClient.html)以取得 CloudWatch Events 功能。CloudWatch Events [使用者指南文件](https://docs.aws.amazon.com/eventbridge/latest/userguide/index.html)和 [API 參考](https://docs.aws.amazon.com/eventbridge/latest/APIReference/index.html)現在可透過 EventBridge 文件網站取得。 ## 新增事件 若要新增自訂 CloudWatch 事件，請使用包含一或多個[https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutEventsRequestEntry.html](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutEventsRequestEntry.html)物件的[https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutEventsRequest.html](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutEventsRequest.html)物件呼叫 `CloudWatchEventsClient’s``putEvents`方法，以提供每個事件的詳細資訊。您可以指定項目的多個參數，例如事件的來源和類型、與事件相關聯的資源等等。 **注意** 對 `putEvents` 的每個呼叫最多可以指定 10 個事件。 **匯入** ``` import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatchevents.CloudWatchEventsClient; import software.amazon.awssdk.services.cloudwatchevents.model.PutEventsRequest; import software.amazon.awssdk.services.cloudwatchevents.model.PutEventsRequestEntry; ``` **Code** ``` public static void putCWEvents(CloudWatchEventsClient cwe, String resourceArn ) { try { final String EVENT_DETAILS = "{ \"key1\": \"value1\", \"key2\": \"value2\" }"; PutEventsRequestEntry requestEntry = PutEventsRequestEntry.builder() .detail(EVENT_DETAILS) .detailType("sampleSubmitted") .resources(resourceArn) .source("aws-sdk-java-cloudwatch-example") .build(); PutEventsRequest request = PutEventsRequest.builder() .entries(requestEntry) .build(); cwe.putEvents(request); System.out.println("Successfully put CloudWatch event"); } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } } ``` 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/0b1785e42949ebf959eaa0f0da4dc2a48f92ea25/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/PutEvents.java)。 ## 新增規則 若要建立或更新規則，請使用規則[https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutRuleRequest.html](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutRuleRequest.html)名稱的 和選用參數呼叫 `CloudWatchEventsClient’s``putRule`方法，例如[事件模式](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-event-patterns.html)、與規則建立關聯的 IAM 角色，以及描述規則執行頻率的[排程表達](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-create-rule-schedule.html)式。 **匯入** ``` import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatchevents.CloudWatchEventsClient; import software.amazon.awssdk.services.cloudwatchevents.model.PutRuleRequest; import software.amazon.awssdk.services.cloudwatchevents.model.PutRuleResponse; import software.amazon.awssdk.services.cloudwatchevents.model.RuleState; ``` **Code** ``` public static void putCWRule(CloudWatchEventsClient cwe, String ruleName, String roleArn) { try { PutRuleRequest request = PutRuleRequest.builder() .name(ruleName) .roleArn(roleArn) .scheduleExpression("rate(5 minutes)") .state(RuleState.ENABLED) .build(); PutRuleResponse response = cwe.putRule(request); System.out.printf( "Successfully created CloudWatch events rule %s with arn %s", roleArn, response.ruleArn()); } catch ( CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } } ``` 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/0b1785e42949ebf959eaa0f0da4dc2a48f92ea25/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/PutRule.java)。 ## 新增目標 目標是觸發規則時叫用的資源。範例目標包括 Amazon EC2 執行個體、 Lambda 函數、 Kinesis 串流、 Amazon ECS 任務、 Step Functions 狀態機器和內建目標。 若要將目標新增至規則，請呼叫 [https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutTargetsRequest.html](https://sdk.amazonaws.com/java/api/latest/software/amazon/awssdk/services/cloudwatchevents/model/PutTargetsRequest.html) `CloudWatchEventsClient’s``putTargets`方法，其中包含要更新的規則和要新增至規則的目標清單。 **匯入** ``` import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException; import software.amazon.awssdk.services.cloudwatchevents.CloudWatchEventsClient; import software.amazon.awssdk.services.cloudwatchevents.model.PutTargetsRequest; import software.amazon.awssdk.services.cloudwatchevents.model.PutTargetsResponse; import software.amazon.awssdk.services.cloudwatchevents.model.Target; ``` **Code** ``` public static void putCWTargets(CloudWatchEventsClient cwe, String ruleName, String functionArn, String targetId ) { try { Target target = Target.builder() .arn(functionArn) .id(targetId) .build(); PutTargetsRequest request = PutTargetsRequest.builder() .targets(target) .rule(ruleName) .build(); PutTargetsResponse response = cwe.putTargets(request); System.out.printf( "Successfully created CloudWatch events target for rule %s", ruleName); } catch (CloudWatchException e) { System.err.println(e.awsErrorDetails().errorMessage()); System.exit(1); } } ``` 請參閱 GitHub 上的[完整範例](https://github.com/awsdocs/aws-doc-sdk-examples/blob/0b1785e42949ebf959eaa0f0da4dc2a48f92ea25/javav2/example_code/cloudwatch/src/main/java/com/example/cloudwatch/PutTargets.java)。 ## 其他資訊 + 《Amazon EventBridge 使用者指南》中的[使用 PutEvents 新增](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-putevents.html)事件 + 《Amazon EventBridge 使用者指南》中的[規則排程表達式](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-create-rule-schedule.html#eb-create-scheduled-rule-schedule) + 《Amazon EventBridge 使用者指南》中的 [的事件類型 CloudWatch Events](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-service-event.html) + 《Amazon EventBridge 使用者指南》中的[事件模式](https://docs.aws.amazon.com/eventbridge/latest/userguide/eb-event-patterns.html) + Amazon EventBridge API 參考中的 [PutEvents](https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_PutEvents.html) + Amazon EventBridge API 參考中的 [PutTargets](https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_PutTargets.html) + Amazon EventBridge API 參考中的 [PutRule](https://docs.aws.amazon.com/eventbridge/latest/APIReference/API_PutRule.html)