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。

# GetPolicy
<a name="JavaApi-GetPolicy"></a>

下列 Java 範例示範如何使用 [GetPolicy](https://docs.aws.amazon.com/privateca/latest/APIReference/API_GetPolicy.html) 操作。

操作會擷取連接至私有 CA 的資源型政策。資源型政策用於啟用跨帳戶 CA 共享。您可以呼叫 [ListCertificateAuthorities](https://docs.aws.amazon.com/privateca/latest/APIReference/API_ListCertificateAuthorities.html) 動作來尋找私有 CA 的 ARN。

相關 API 動作包括 [PutPolicy](https://docs.aws.amazon.com/privateca/latest/APIReference/API_PutPolicy.html) 和 [DeletePolicy](https://docs.aws.amazon.com/privateca/latest/APIReference/API_DeletePolicy.html)。

```
package com.amazonaws.samples;

import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.profile.ProfileCredentialsProvider;
import com.amazonaws.client.builder.AwsClientBuilder;
import com.amazonaws.client.builder.AwsClientBuilder.EndpointConfiguration;
import com.amazonaws.auth.AWSStaticCredentialsProvider;

import com.amazonaws.services.acmpca.AWSACMPCA;
import com.amazonaws.services.acmpca.AWSACMPCAClientBuilder;

import com.amazonaws.AmazonClientException;
import com.amazonaws.services.acmpca.model.GetPolicyRequest;
import com.amazonaws.services.acmpca.model.GetPolicyResult;
import com.amazonaws.services.acmpca.model.AWSACMPCAException;
import com.amazonaws.services.acmpca.model.InvalidArnException;
import com.amazonaws.services.acmpca.model.InvalidStateException;
import com.amazonaws.services.acmpca.model.RequestFailedException;
import com.amazonaws.services.acmpca.model.ResourceNotFoundException;

public class GetPolicy {

    public static void main(String[] args) throws Exception {

        // Retrieve your credentials from the C:\Users\name\.aws\credentials file
        // in Windows or the .aws/credentials file in Linux.
        AWSCredentials credentials = null;
        try {
            credentials = new ProfileCredentialsProvider("default").getCredentials();
        } catch (Exception e) {
            throw new AmazonClientException("Cannot load your credentials from file.", e);
        }

        // Define the endpoint for your sample.
        String endpointRegion = "{{region}}";  // Substitute your region here, e.g. "us-west-2"
        String endpointProtocol = "https://acm-pca." + endpointRegion + ".amazonaws.com/";
        EndpointConfiguration endpoint =
            new AwsClientBuilder.EndpointConfiguration(endpointProtocol, endpointRegion);

        // Create a client that you can use to make requests.
        AWSACMPCA client = AWSACMPCAClientBuilder.standard()
            .withEndpointConfiguration(endpoint)
            .withCredentials(new AWSStaticCredentialsProvider(credentials))
            .build();

        // Create the request object.
        GetPolicyRequest req = new GetPolicyRequest();

        // Set the resource ARN.
        req.withResourceArn("arn:{{aws}}:acm-pca:{{us-east-1}}:{{111122223333}}:certificate-authority/{{11223344-1234-1122-2233-112233445566}}");

        // Retrieve a list of your CAs.
        GetPolicyResult result= null;
        try {
            result = client.getPolicy(req);
        } catch (InvalidArnException ex) {
            throw ex;
        } catch (InvalidStateException ex) {
            throw ex;
        } catch (RequestFailedException ex) {
            throw ex;
        } catch (ResourceNotFoundException ex) {
            throw ex;
        } catch (AWSACMPCAException ex) {
            throw ex;
        }

        // Display the policy.
        System.out.println(result.getPolicy());
    }
}
```