# 通过 AWS SDK 使用 IAM Policy Builder API 以下代码示例展示了如何： + 使用面向对象的 API 创建 IAM policy。 + 将 IAM Policy Builder API 与 IAM 服务结合使用。 ------ #### [ Java ] **适用于 Java 的 SDK 2.x** 查看 GitHub，了解更多信息。在 [AWS 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/iam#code-examples)中查找完整示例，了解如何进行设置和运行。 示例使用以下导入。 ``` import org.slf4j.Logger; import org.slf4j.LoggerFactory; import software.amazon.awssdk.policybuilder.iam.IamConditionOperator; import software.amazon.awssdk.policybuilder.iam.IamEffect; import software.amazon.awssdk.policybuilder.iam.IamPolicy; import software.amazon.awssdk.policybuilder.iam.IamPolicyWriter; import software.amazon.awssdk.policybuilder.iam.IamPrincipal; import software.amazon.awssdk.policybuilder.iam.IamPrincipalType; import software.amazon.awssdk.policybuilder.iam.IamResource; import software.amazon.awssdk.policybuilder.iam.IamStatement; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.iam.IamClient; import software.amazon.awssdk.services.iam.model.GetPolicyResponse; import software.amazon.awssdk.services.iam.model.GetPolicyVersionResponse; import software.amazon.awssdk.services.sts.StsClient; import java.net.URLDecoder; import java.nio.charset.StandardCharsets; import java.util.Arrays; import java.util.List; ``` 创建基于时间的策略。 ``` public String timeBasedPolicyExample() { IamPolicy policy = IamPolicy.builder() .addStatement(b -> b .effect(IamEffect.ALLOW) .addAction("dynamodb:GetItem") .addResource(IamResource.ALL) .addCondition(b1 -> b1 .operator(IamConditionOperator.DATE_GREATER_THAN) .key("aws:CurrentTime") .value("2020-04-01T00:00:00Z")) .addCondition(b1 -> b1 .operator(IamConditionOperator.DATE_LESS_THAN) .key("aws:CurrentTime") .value("2020-06-30T23:59:59Z"))) .build(); // Use an IamPolicyWriter to write out the JSON string to a more readable // format. return policy.toJson(IamPolicyWriter.builder() .prettyPrint(true) .build()); } ``` 创建具有多个条件的策略。 ``` public String multipleConditionsExample() { IamPolicy policy = IamPolicy.builder() .addStatement(b -> b .effect(IamEffect.ALLOW) .addAction("dynamodb:GetItem") .addAction("dynamodb:BatchGetItem") .addAction("dynamodb:Query") .addAction("dynamodb:PutItem") .addAction("dynamodb:UpdateItem") .addAction("dynamodb:DeleteItem") .addAction("dynamodb:BatchWriteItem") .addResource("arn:aws:dynamodb:*:*:table/table-name") .addConditions(IamConditionOperator.STRING_EQUALS .addPrefix("ForAllValues:"), "dynamodb:Attributes", List.of("column-name1", "column-name2", "column-name3")) .addCondition(b1 -> b1 .operator(IamConditionOperator.STRING_EQUALS .addSuffix("IfExists")) .key("dynamodb:Select") .value("SPECIFIC_ATTRIBUTES"))) .build(); return policy.toJson(IamPolicyWriter.builder() .prettyPrint(true).build()); } ``` 在策略中使用主体。 ``` public String specifyPrincipalsExample() { IamPolicy policy = IamPolicy.builder() .addStatement(b -> b .effect(IamEffect.DENY) .addAction("s3:*") .addPrincipal(IamPrincipal.ALL) .addResource("arn:aws:s3:::amzn-s3-demo-bucket/*") .addResource("arn:aws:s3:::amzn-s3-demo-bucket") .addCondition(b1 -> b1 .operator(IamConditionOperator.ARN_NOT_EQUALS) .key("aws:PrincipalArn") .value("arn:aws:iam::444455556666:user/user-name"))) .build(); return policy.toJson(IamPolicyWriter.builder() .prettyPrint(true).build()); } ``` 允许跨账户存取。 ``` public String allowCrossAccountAccessExample() { IamPolicy policy = IamPolicy.builder() .addStatement(b -> b .effect(IamEffect.ALLOW) .addPrincipal(IamPrincipalType.AWS, "111122223333") .addAction("s3:PutObject") .addResource("arn:aws:s3:::amzn-s3-demo-bucket/*") .addCondition(b1 -> b1 .operator(IamConditionOperator.STRING_EQUALS) .key("s3:x-amz-acl") .value("bucket-owner-full-control"))) .build(); return policy.toJson(IamPolicyWriter.builder() .prettyPrint(true).build()); } ``` 生成并上传 `IamPolicy`。 ``` public String createAndUploadPolicyExample(IamClient iam, String accountID, String policyName) { // Build the policy. IamPolicy policy = IamPolicy.builder() // 'version' defaults to "2012-10-17". .addStatement(IamStatement.builder() .effect(IamEffect.ALLOW) .addAction("dynamodb:PutItem") .addResource("arn:aws:dynamodb:us-east-1:" + accountID + ":table/exampleTableName") .build()) .build(); // Upload the policy. iam.createPolicy(r -> r.policyName(policyName).policyDocument(policy.toJson())); return policy.toJson(IamPolicyWriter.builder().prettyPrint(true).build()); } ``` 下载并使用 `IamPolicy`。 ``` public String createNewBasedOnExistingPolicyExample(IamClient iam, String accountID, String policyName, String newPolicyName) { String policyArn = "arn:aws:iam::" + accountID + ":policy/" + policyName; GetPolicyResponse getPolicyResponse = iam.getPolicy(r -> r.policyArn(policyArn)); String policyVersion = getPolicyResponse.policy().defaultVersionId(); GetPolicyVersionResponse getPolicyVersionResponse = iam .getPolicyVersion(r -> r.policyArn(policyArn).versionId(policyVersion)); // Create an IamPolicy instance from the JSON string returned from IAM. String decodedPolicy = URLDecoder.decode(getPolicyVersionResponse.policyVersion().document(), StandardCharsets.UTF_8); IamPolicy policy = IamPolicy.fromJson(decodedPolicy); /* * All IamPolicy components are immutable, so use the copy method that creates a * new instance that * can be altered in the same method call. * * Add the ability to get an item from DynamoDB as an additional action. */ IamStatement newStatement = policy.statements().get(0).copy(s -> s.addAction("dynamodb:GetItem")); // Create a new statement that replaces the original statement. IamPolicy newPolicy = policy.copy(p -> p.statements(Arrays.asList(newStatement))); // Upload the new policy. IAM now has both policies. iam.createPolicy(r -> r.policyName(newPolicyName) .policyDocument(newPolicy.toJson())); return newPolicy.toJson(IamPolicyWriter.builder().prettyPrint(true).build()); } ``` + 有关更多信息，请参阅《AWS SDK for Java 2.x 开发人员指南》[https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/feature-iam-policy-builder.html](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/feature-iam-policy-builder.html)。 + 有关 API 详细信息，请参阅《AWS SDK for Java 2.x API Reference》**中的以下主题。 + [CreatePolicy](https://docs.aws.amazon.com/goto/SdkForJavaV2/iam-2010-05-08/CreatePolicy) + [GetPolicy](https://docs.aws.amazon.com/goto/SdkForJavaV2/iam-2010-05-08/GetPolicy) + [GetPolicyVersion](https://docs.aws.amazon.com/goto/SdkForJavaV2/iam-2010-05-08/GetPolicyVersion) ------ 有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 [将此服务与 AWS SDK 结合使用](sdk-general-information-section.md) 本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。