Where:
filter - The name of the subscription filter (for example, MyFilter).
logGroup - The name of the log group. (for example, testgroup).
""";
if (args.length != 2) {
System.out.println(usage);
System.exit(1);
}
String filter = args[0];
String logGroup = args[1];
CloudWatchLogsClient logs = CloudWatchLogsClient.builder()
.build();
deleteSubFilter(logs, filter, logGroup);
logs.close();
}
public static void deleteSubFilter(CloudWatchLogsClient logs, String filter, String logGroup) {
try {
DeleteSubscriptionFilterRequest request = DeleteSubscriptionFilterRequest.builder()
.filterName(filter)
.logGroupName(logGroup)
.build();
logs.deleteSubscriptionFilter(request);
System.out.printf("Successfully deleted CloudWatch logs subscription filter %s", filter);
} catch (CloudWatchException e) {
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
}
}
}
```
+ API の詳細については、*AWS SDK for Java 2.x API リファレンス*の「[DeleteSubscriptionFilter](https://docs.aws.amazon.com/goto/SdkForJavaV2/logs-2014-03-28/DeleteSubscriptionFilter)」を参照してください。
### `DescribeLogStreams`
次のコード例は、`DescribeLogStreams` を使用する方法を示しています。
**SDK for Java 2.x**
GitHub には、その他のリソースもあります。用例一覧を検索し、[AWS コード例リポジトリ](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/cloudwatch-logs#code-examples)での設定と実行の方法を確認してください。
指定されたプレフィックスに一致する、指定されたロググループ内のログストリームを検索します。
```
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class CloudWatchLogsSearch {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
logGroupName - The name of the log group (for example, WeathertopJavaContainerLogs).
logStreamName - The name of the log stream (for example, weathertop-java-stream).
pattern - the pattern to use (for example, INFO)
""";
if (args.length != 3) {
System.out.print(usage);
System.exit(1);
}
String logGroupName = args[0] ;
String logStreamName = args[1] ;
String pattern = args[2] ;
CloudWatchLogsClient cwlClient = CloudWatchLogsClient.builder()
.region(Region.US_EAST_1)
.build();
searchLogStreamsAndFilterEvents(cwlClient, logGroupName, logStreamName, pattern);
}
/**
* Searches for log streams with a specific prefix within a log group and filters log events based on a specified pattern.
*
* @param cwlClient the CloudWatchLogsClient used to interact with AWS CloudWatch Logs
* @param logGroupName the name of the log group to search within
* @param logStreamPrefix the prefix of the log streams to search for
* @param pattern the pattern to filter log events by
*/
public static void searchLogStreamsAndFilterEvents(CloudWatchLogsClient cwlClient, String logGroupName, String logStreamPrefix, String pattern) {
DescribeLogStreamsRequest describeLogStreamsRequest = DescribeLogStreamsRequest.builder()
.logGroupName(logGroupName)
.logStreamNamePrefix(logStreamPrefix)
.build();
DescribeLogStreamsResponse describeLogStreamsResponse = cwlClient.describeLogStreams(describeLogStreamsRequest);
List logStreams = describeLogStreamsResponse.logStreams();
for (LogStream logStream : logStreams) {
String logStreamName = logStream.logStreamName();
System.out.println("Searching in log stream: " + logStreamName);
FilterLogEventsRequest filterLogEventsRequest = FilterLogEventsRequest.builder()
.logGroupName(logGroupName)
.logStreamNames(logStreamName)
.filterPattern(pattern)
.build();
FilterLogEventsResponse filterLogEventsResponse = cwlClient.filterLogEvents(filterLogEventsRequest);
for (FilteredLogEvent event : filterLogEventsResponse.events()) {
System.out.println(event.message());
}
System.out.println("--------------------------------------------------"); // Separator for better readability
}
}
}
```
指定されたロググループ内の最新のログストリームに関するメタデータを出力します。
```
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class CloudWatchLogQuery {
public static void main(final String[] args) {
final String usage = """
Usage:
Where:
logGroupName - The name of the log group (for example, /aws/lambda/ChatAIHandler).
""";
if (args.length != 1) {
System.out.print(usage);
System.exit(1);
}
String logGroupName = "/aws/lambda/ChatAIHandler" ; //args[0];
CloudWatchLogsClient logsClient = CloudWatchLogsClient.builder()
.region(Region.US_EAST_1)
.build();
describeMostRecentLogStream(logsClient, logGroupName);
}
/**
* Describes and prints metadata about the most recent log stream in the specified log group.
*
* @param logsClient the CloudWatchLogsClient used to interact with AWS CloudWatch Logs
* @param logGroupName the name of the log group
*/
public static void describeMostRecentLogStream(CloudWatchLogsClient logsClient, String logGroupName) {
DescribeLogStreamsRequest streamsRequest = DescribeLogStreamsRequest.builder()
.logGroupName(logGroupName)
.orderBy(OrderBy.LAST_EVENT_TIME)
.descending(true)
.limit(1)
.build();
try {
DescribeLogStreamsResponse streamsResponse = logsClient.describeLogStreams(streamsRequest);
List logStreams = streamsResponse.logStreams();
if (logStreams.isEmpty()) {
System.out.println("No log streams found for log group: " + logGroupName);
return;
}
LogStream stream = logStreams.get(0);
System.out.println("Most Recent Log Stream:");
System.out.println(" Name: " + stream.logStreamName());
System.out.println(" ARN: " + stream.arn());
System.out.println(" Creation Time: " + stream.creationTime());
System.out.println(" First Event Time: " + stream.firstEventTimestamp());
System.out.println(" Last Event Time: " + stream.lastEventTimestamp());
System.out.println(" Stored Bytes: " + stream.storedBytes());
System.out.println(" Upload Sequence Token: " + stream.uploadSequenceToken());
} catch (CloudWatchLogsException e) {
System.err.println("Failed to describe log stream: " + e.awsErrorDetails().errorMessage());
}
}
}
```
+ API の詳細については、「*AWS SDK for Java 2.x API リファレンス*」の「[DescribeLogStreams](https://docs.aws.amazon.com/goto/SdkForJavaV2/logs-2014-03-28/DescribeLogStreams)」を参照してください。
### `DescribeSubscriptionFilters`
次のコード例は、`DescribeSubscriptionFilters` を使用する方法を示しています。
**SDK for Java 2.x**
GitHub には、その他のリソースもあります。用例一覧を検索し、[AWS コード例リポジトリ](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/cloudwatch-logs#code-examples)での設定と実行の方法を確認してください。
```
import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException;
import software.amazon.awssdk.services.cloudwatchlogs.CloudWatchLogsClient;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeSubscriptionFiltersRequest;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeSubscriptionFiltersResponse;
import software.amazon.awssdk.services.cloudwatchlogs.model.SubscriptionFilter;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class DescribeSubscriptionFilters {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
logGroup - A log group name (for example, myloggroup).
""";
if (args.length != 1) {
System.out.println(usage);
System.exit(1);
}
String logGroup = args[0];
CloudWatchLogsClient logs = CloudWatchLogsClient.builder()
.credentialsProvider(ProfileCredentialsProvider.create())
.build();
describeFilters(logs, logGroup);
logs.close();
}
public static void describeFilters(CloudWatchLogsClient logs, String logGroup) {
try {
boolean done = false;
String newToken = null;
while (!done) {
DescribeSubscriptionFiltersResponse response;
if (newToken == null) {
DescribeSubscriptionFiltersRequest request = DescribeSubscriptionFiltersRequest.builder()
.logGroupName(logGroup)
.limit(1).build();
response = logs.describeSubscriptionFilters(request);
} else {
DescribeSubscriptionFiltersRequest request = DescribeSubscriptionFiltersRequest.builder()
.nextToken(newToken)
.logGroupName(logGroup)
.limit(1).build();
response = logs.describeSubscriptionFilters(request);
}
for (SubscriptionFilter filter : response.subscriptionFilters()) {
System.out.printf("Retrieved filter with name %s, " + "pattern %s " + "and destination arn %s",
filter.filterName(),
filter.filterPattern(),
filter.destinationArn());
}
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");
}
}
```
+ API の詳細については、*AWS SDK for Java 2.x API リファレンス*の「[DescribeSubscriptionFilters](https://docs.aws.amazon.com/goto/SdkForJavaV2/logs-2014-03-28/DescribeSubscriptionFilters)」を参照してください。
### `GetLogEvents`
次のコード例は、`GetLogEvents` を使用する方法を示しています。
**SDK for Java 2.x**
GitHub には、その他のリソースもあります。用例一覧を検索し、[AWS コード例リポジトリ](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/cloudwatch#code-examples)での設定と実行の方法を確認してください。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatch.model.CloudWatchException;
import software.amazon.awssdk.services.cloudwatchlogs.CloudWatchLogsClient;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeLogStreamsRequest;
import software.amazon.awssdk.services.cloudwatchlogs.model.DescribeLogStreamsResponse;
import software.amazon.awssdk.services.cloudwatchlogs.model.GetLogEventsRequest;
import software.amazon.awssdk.services.cloudwatchlogs.model.GetLogEventsResponse;
import java.time.Instant;
import java.time.temporal.ChronoUnit;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class GetLogEvents {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
logGroupName - The name of the log group (for example, myloggroup).
logStreamName - The name of the log stream (for example, mystream).
""";
// if (args.length != 2) {
// System.out.print(usage);
// System.exit(1);
// }
String logGroupName = "WeathertopJavaContainerLogs" ; //args[0];
String logStreamName = "weathertop-java-stream" ; //args[1];
Region region = Region.US_EAST_1 ;
CloudWatchLogsClient cloudWatchLogsClient = CloudWatchLogsClient.builder()
.region(region)
.build();
getCWLogEvents(cloudWatchLogsClient, logGroupName, logStreamName);
cloudWatchLogsClient.close();
}
public static void getCWLogEvents(CloudWatchLogsClient cloudWatchLogsClient,
String logGroupName,
String logStreamPrefix) {
try {
// First, find the exact log stream name
DescribeLogStreamsRequest describeRequest = DescribeLogStreamsRequest.builder()
.logGroupName(logGroupName)
.logStreamNamePrefix(logStreamPrefix)
.limit(1) // get the first matching stream
.build();
DescribeLogStreamsResponse describeResponse = cloudWatchLogsClient.describeLogStreams(describeRequest);
if (describeResponse.logStreams().isEmpty()) {
System.out.println("No matching log streams found for prefix: " + logStreamPrefix);
return;
}
String exactLogStreamName = describeResponse.logStreams().get(0).logStreamName();
System.out.println("Using exact log stream: " + exactLogStreamName);
long startTime = Instant.now().minus(7, ChronoUnit.DAYS).toEpochMilli();
long endTime = Instant.now().toEpochMilli();
GetLogEventsRequest getLogEventsRequest = GetLogEventsRequest.builder()
.logGroupName(logGroupName)
.logStreamName(exactLogStreamName) // <-- exact name, not prefix
.startTime(startTime)
.endTime(endTime)
.startFromHead(true)
.build();
GetLogEventsResponse response = cloudWatchLogsClient.getLogEvents(getLogEventsRequest);
if (response.events().isEmpty()) {
System.out.println("No log events found in the past 7 days.");
} else {
response.events().forEach(e -> System.out.println(e.message()));
}
} catch (CloudWatchException e) {
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
}
}
}
```
+ API の詳細については、「*AWS SDK for Java 2.x API リファレンス*」の「[GetLogEvents](https://docs.aws.amazon.com/goto/SdkForJavaV2/logs-2014-03-28/GetLogEvents)」を参照してください。
### `PutSubscriptionFilter`
次のコード例は、`PutSubscriptionFilter` を使用する方法を示しています。
**SDK for Java 2.x**
GitHub には、その他のリソースもあります。用例一覧を検索し、[AWS コード例リポジトリ](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/cloudwatch-logs#code-examples)での設定と実行の方法を確認してください。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.cloudwatchlogs.CloudWatchLogsClient;
import software.amazon.awssdk.services.cloudwatchlogs.model.CloudWatchLogsException;
import software.amazon.awssdk.services.cloudwatchlogs.model.PutSubscriptionFilterRequest;
/**
* Before running this code example, you need to grant permission to CloudWatch
* Logs the right to execute your Lambda function.
* To perform this task, you can use this CLI command:
*
* aws lambda add-permission --function-name "lamda1" --statement-id "lamda1"
* --principal "logs.us-west-2.amazonaws.com" --action "lambda:InvokeFunction"
* --source-arn "arn:aws:logs:us-west-2:111111111111:log-group:testgroup:*"
* --source-account "111111111111"
*
* Make sure you replace the function name with your function name and replace
* '111111111111' with your account details.
* For more information, see "Subscription Filters with AWS Lambda" in the
* Amazon CloudWatch Logs Guide.
*
*
* Also, before running this Java V2 code example,set up your development
* environment,including your credentials.
*
* For more information,see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
*/
public class PutSubscriptionFilter {
public static void main(String[] args) {
final String usage = """
Usage:
\s
Where:
filter - A filter name (for example, myfilter).
pattern - A filter pattern (for example, ERROR).
logGroup - A log group name (testgroup).
functionArn - An AWS Lambda function ARN (for example, arn:aws:lambda:us-west-2:111111111111:function:lambda1) .
""";
if (args.length != 4) {
System.out.println(usage);
System.exit(1);
}
String filter = args[0];
String pattern = args[1];
String logGroup = args[2];
String functionArn = args[3];
Region region = Region.US_WEST_2;
CloudWatchLogsClient cwl = CloudWatchLogsClient.builder()
.region(region)
.build();
putSubFilters(cwl, filter, pattern, logGroup, functionArn);
cwl.close();
}
public static void putSubFilters(CloudWatchLogsClient cwl,
String filter,
String pattern,
String logGroup,
String functionArn) {
try {
PutSubscriptionFilterRequest request = PutSubscriptionFilterRequest.builder()
.filterName(filter)
.filterPattern(pattern)
.logGroupName(logGroup)
.destinationArn(functionArn)
.build();
cwl.putSubscriptionFilter(request);
System.out.printf(
"Successfully created CloudWatch logs subscription filter %s",
filter);
} catch (CloudWatchLogsException e) {
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
}
}
}
```
+ API の詳細については、*AWS SDK for Java 2.x API リファレンス*の「[PutSubscriptionFilter](https://docs.aws.amazon.com/goto/SdkForJavaV2/logs-2014-03-28/PutSubscriptionFilter)」を参照してください。
### `StartLiveTail`
次のコード例は、`StartLiveTail` を使用する方法を示しています。
**SDK for Java 2.x**
必要なファイルを含めます。
```
import io.reactivex.FlowableSubscriber;
import io.reactivex.annotations.NonNull;
import org.reactivestreams.Subscription;
import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.services.cloudwatchlogs.CloudWatchLogsAsyncClient;
import software.amazon.awssdk.services.cloudwatchlogs.model.LiveTailSessionLogEvent;
import software.amazon.awssdk.services.cloudwatchlogs.model.LiveTailSessionStart;
import software.amazon.awssdk.services.cloudwatchlogs.model.LiveTailSessionUpdate;
import software.amazon.awssdk.services.cloudwatchlogs.model.StartLiveTailRequest;
import software.amazon.awssdk.services.cloudwatchlogs.model.StartLiveTailResponseHandler;
import software.amazon.awssdk.services.cloudwatchlogs.model.CloudWatchLogsException;
import software.amazon.awssdk.services.cloudwatchlogs.model.StartLiveTailResponseStream;
import java.util.Date;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
```
Live Tail セッションのイベントを処理します。
```
private static StartLiveTailResponseHandler getStartLiveTailResponseStreamHandler(
AtomicReference subscriptionAtomicReference) {
return StartLiveTailResponseHandler.builder()
.onResponse(r -> System.out.println("Received initial response"))
.onError(throwable -> {
CloudWatchLogsException e = (CloudWatchLogsException) throwable.getCause();
System.err.println(e.awsErrorDetails().errorMessage());
System.exit(1);
})
.subscriber(() -> new FlowableSubscriber<>() {
@Override
public void onSubscribe(@NonNull Subscription s) {
subscriptionAtomicReference.set(s);
s.request(Long.MAX_VALUE);
}
@Override
public void onNext(StartLiveTailResponseStream event) {
if (event instanceof LiveTailSessionStart) {
LiveTailSessionStart sessionStart = (LiveTailSessionStart) event;
System.out.println(sessionStart);
} else if (event instanceof LiveTailSessionUpdate) {
LiveTailSessionUpdate sessionUpdate = (LiveTailSessionUpdate) event;
List logEvents = sessionUpdate.sessionResults();
logEvents.forEach(e -> {
long timestamp = e.timestamp();
Date date = new Date(timestamp);
System.out.println("[" + date + "] " + e.message());
});
} else {
throw CloudWatchLogsException.builder().message("Unknown event type").build();
}
}
@Override
public void onError(Throwable throwable) {
System.out.println(throwable.getMessage());
System.exit(1);
}
@Override
public void onComplete() {
System.out.println("Completed Streaming Session");
}
})
.build();
}
```
Live Tail セッションを開始します。
```
CloudWatchLogsAsyncClient cloudWatchLogsAsyncClient =
CloudWatchLogsAsyncClient.builder()
.credentialsProvider(ProfileCredentialsProvider.create())
.build();
StartLiveTailRequest request =
StartLiveTailRequest.builder()
.logGroupIdentifiers(logGroupIdentifiers)
.logStreamNames(logStreamNames)
.logEventFilterPattern(logEventFilterPattern)
.build();
/* Create a reference to store the subscription */
final AtomicReference subscriptionAtomicReference = new AtomicReference<>(null);
cloudWatchLogsAsyncClient.startLiveTail(request, getStartLiveTailResponseStreamHandler(subscriptionAtomicReference));
```
一定時間が経過したら Live Tail セッションを停止します。
```
/* Set a timeout for the session and cancel the subscription. This will:
* 1). Close the stream
* 2). Stop the Live Tail session
*/
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
if (subscriptionAtomicReference.get() != null) {
subscriptionAtomicReference.get().cancel();
System.out.println("Subscription to stream closed");
}
```
+ API の詳細については、*AWS SDK for Java 2.x API リファレンス*の「[StartLiveTail](https://docs.aws.amazon.com/goto/SdkForJavaV2/logs-2014-03-28/StartLiveTail)」を参照してください。
## シナリオ
### スケジュールされたイベントを使用した Lambda 関数の呼び出し
次のコード例は、Amazon EventBridge スケジュールされたイベントによって呼び出される AWS Lambda 関数を作成する方法を示しています。
**SDK for Java 2.x**
AWS Lambda 関数を呼び出す Amazon EventBridge スケジュールされたイベントを作成する方法を示します。cron 式を使用して Lambda 関数が呼び出されるタイミングをスケジュールするように EventBridge を設定します。この例では、Lambda Java ランタイム API を使用して Lambda 関数を作成します。この例では、さまざまな AWS サービスを呼び出して、特定のユースケースを実行します。この例では、年間の記念日に従業員を祝福するモバイルテキストメッセージを従業員に送信するアプリを作成する方法を示します。
完全なソースコードとセットアップおよび実行の手順については、[GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/usecases/creating_scheduled_events) で完全な例を参照してください。
**この例で使用されているサービス**
+ CloudWatch Logs
+ DynamoDB
+ EventBridge
+ Lambda
+ Amazon SNS