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。

# AWS STS 使用適用於 Java 的 SDK 2.x 的範例
<a name="java_sts_code_examples"></a>

下列程式碼範例示範如何使用 AWS SDK for Java 2.x 搭配 來執行動作和實作常見案例 AWS STS。

*Actions* 是大型程式的程式碼摘錄，必須在內容中執行。雖然動作會告訴您如何呼叫個別服務函數，但您可以在其相關情境中查看內容中的動作。

每個範例均包含完整原始碼的連結，您可在連結中找到如何設定和執行內容中程式碼的相關指示。

**Topics**
+ [動作](#actions)

## 動作
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### `AssumeRole`
<a name="sts_AssumeRole_java_topic"></a>

以下程式碼範例顯示如何使用 `AssumeRole`。

**SDK for Java 2.x**  
 GitHub 上提供更多範例。尋找完整範例，並了解如何在 [AWS 程式碼範例儲存庫](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/sts#code-examples)中設定和執行。

```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.sts.StsClient;
import software.amazon.awssdk.services.sts.model.AssumeRoleRequest;
import software.amazon.awssdk.services.sts.model.StsException;
import software.amazon.awssdk.services.sts.model.AssumeRoleResponse;
import software.amazon.awssdk.services.sts.model.Credentials;
import java.time.Instant;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.format.FormatStyle;
import java.util.Locale;

/**
 * To make this code example work, create a Role that you want to assume.
 * Then define a Trust Relationship in the AWS Console. You can use this as an
 * example:
 *
 * {
 * "Version":"2012-10-17",		 	 	 
 * "Statement": [
 * {
 * "Effect": "Allow",
 * "Principal": {
 * "AWS": "<Specify the ARN of your IAM user you are using in this code example>"
 * },
 * "Action": "sts:AssumeRole"
 * }
 * ]
 * }
 *
 * For more information, see "Editing the Trust Relationship for an Existing
 * Role" in the AWS Directory Service guide.
 *
 * Also, set up your development environment, including your credentials.
 *
 * For information, see this documentation topic:
 *
 * https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
 */
public class AssumeRole {
    public static void main(String[] args) {
        final String usage = """

                Usage:
                    <roleArn> <roleSessionName>\s

                Where:
                    roleArn - The Amazon Resource Name (ARN) of the role to assume (for example, arn:aws:iam::000008047983:role/s3role).\s
                    roleSessionName - An identifier for the assumed role session (for example, mysession).\s
                """;

        if (args.length != 2) {
            System.out.println(usage);
            System.exit(1);
        }

        String roleArn = args[0];
        String roleSessionName = args[1];
        Region region = Region.US_EAST_1;
        StsClient stsClient = StsClient.builder()
                .region(region)
                .build();

        assumeGivenRole(stsClient, roleArn, roleSessionName);
        stsClient.close();
    }

    public static void assumeGivenRole(StsClient stsClient, String roleArn, String roleSessionName) {
        try {
            AssumeRoleRequest roleRequest = AssumeRoleRequest.builder()
                    .roleArn(roleArn)
                    .roleSessionName(roleSessionName)
                    .build();

            AssumeRoleResponse roleResponse = stsClient.assumeRole(roleRequest);
            Credentials myCreds = roleResponse.credentials();

            // Display the time when the temp creds expire.
            Instant exTime = myCreds.expiration();
            String tokenInfo = myCreds.sessionToken();

            // Convert the Instant to readable date.
            DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.SHORT)
                    .withLocale(Locale.US)
                    .withZone(ZoneId.systemDefault());

            formatter.format(exTime);
            System.out.println("The token " + tokenInfo + "  expires on " + exTime);

        } catch (StsException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
}
```
+  如需 API 詳細資訊，請參閱 *AWS SDK for Java 2.x API Reference* 中的 [AssumeRole](https://docs.aws.amazon.com/goto/SdkForJavaV2/sts-2011-06-15/AssumeRole)。