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。

# GetCertificateAuthorityCertificate
<a name="JavaApi-GetCACertificate"></a>

以下 Java 範例會示範如何使用 [GetCertificateAuthorityCertificate](https://docs.aws.amazon.com/privateca/latest/APIReference/API_GetCertificateAuthorityCertificate.html) 操作。

此操作能為您的私有憑證授權機構 (CA) 擷取憑證和憑證鏈。憑證和鏈結都是 PEM 格式的 base64 編碼字串。憑證鏈不包含 CA 憑證。憑證鏈中的每個憑證都會依序簽署。

```
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.services.acmpca.model.GetCertificateAuthorityCertificateRequest;
import com.amazonaws.services.acmpca.model.GetCertificateAuthorityCertificateResult;

import com.amazonaws.AmazonClientException;
import com.amazonaws.services.acmpca.model.ResourceNotFoundException;
import com.amazonaws.services.acmpca.model.InvalidStateException;
import com.amazonaws.services.acmpca.model.InvalidArnException;

public class GetCertificateAuthorityCertificate {

   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 disk", 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 a request object
      GetCertificateAuthorityCertificateRequest req =
            new GetCertificateAuthorityCertificateRequest();

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

      // Create a result object.
      GetCertificateAuthorityCertificateResult result = null;
      try {
         result = client.getCertificateAuthorityCertificate(req);
      } catch (ResourceNotFoundException ex) {
         throw ex;
      } catch (InvalidStateException ex) {
         throw ex;
      } catch (InvalidArnException ex) {
         throw ex;
      }

      // Retrieve and display the certificate information.
      String strPcaCert = result.getCertificate();
      System.out.println(strPcaCert);
      String strPCACChain = result.getCertificateChain();
      System.out.println(strPCACChain);
   }
}
```

您的輸出應為類似以下您指定的憑證授權單位 (CA) 的憑證和憑證鏈。

```
-----BEGIN CERTIFICATE----- {{base64-encoded certificate}} -----END CERTIFICATE-----
	
-----BEGIN CERTIFICATE----- {{base64-encoded certificate}} -----END CERTIFICATE-----
```