ブラウザの同一オリジンポリシーにより、データが交換されたり、異なるドメイン名間でリソースが共有されたりすると、クロスオリジンリクエストが拒否される場合があります。 この問題を解決するには、クロスオリジンリソース共有 (CORS) ルールを設定します。 CORSルールでは、リクエストを送信できるドメイン名、クロスオリジンリクエストの送信に使用できるメソッド、および許可されるヘッダーを指定できます。
使用上の注意
このトピックでは、中国 (杭州) リージョンのパブリックエンドポイントを使用します。 OSSと同じリージョンにある他のAlibaba CloudサービスからOSSにアクセスする場合は、内部エンドポイントを使用します。 OSSリージョンとエンドポイントの詳細については、「リージョン、エンドポイント、オープンポート」をご参照ください。
このトピックでは、アクセス資格情報は環境変数から取得します。 アクセス資格情報の設定方法の詳細については、「アクセス資格情報の設定」をご参照ください。
このトピックでは、OSSエンドポイントを使用してOSSClientインスタンスを作成します。 カスタムドメイン名またはSecurity Token Service (STS) を使用してOSSClientインスタンスを作成する場合は、「OSSClientインスタンスの作成」をご参照ください。
CORSルールを設定するには、
oss:PutBucketCors
権限が必要です。 CORSルールを照会するには、oss:GetBucketCors
権限が必要です。 CORSルールを削除するには、oss:DeleteBucketCors
権限が必要です。 詳細については、「RAMユーザーへのカスタムポリシーのアタッチ」をご参照ください。
CORSルールの設定
次のサンプルコードは、特定のバケットにCORSルールを設定する方法の例を示しています。
import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.SetBucketCORSRequest;
import java.util.ArrayList;
public class Demo {
public static void main(String[] args) throws Exception {
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint.
String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
// Specify the name of the bucket. Example: examplebucket.
String bucketName = "examplebucket";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
String region = "cn-hangzhou";
// Create an OSSClient instance.
ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
OSS ossClient = OSSClientBuilder.create()
.endpoint(endpoint)
.credentialsProvider(credentialsProvider)
.clientConfiguration(clientBuilderConfiguration)
.region(region)
.build();
try {
SetBucketCORSRequest request = new SetBucketCORSRequest(bucketName);
// You can configure up to 10 CORS rules for a bucket.
ArrayList<SetBucketCORSRequest.CORSRule> putCorsRules = new ArrayList<SetBucketCORSRequest.CORSRule>();
SetBucketCORSRequest.CORSRule corRule = new SetBucketCORSRequest.CORSRule();
ArrayList<String> allowedOrigin = new ArrayList<String>();
// Specify the origins from which cross-origin requests are allowed.
allowedOrigin.add( "http://example.com");
ArrayList<String> allowedMethod = new ArrayList<String>();
// Specify the methods that can be used to send cross-origin requests, including GET, PUT, DELETE, POST, and HEAD.
allowedMethod.add("GET");
ArrayList<String> allowedHeader = new ArrayList<String>();
// Specify whether the headers that are specified by Access-Control-Request-Headers in the OPTIONS preflight request are allowed.
allowedHeader.add("x-oss-test");
ArrayList<String> exposedHeader = new ArrayList<String>();
// Specify the response headers for allowed access requests from applications.
exposedHeader.add("x-oss-test1");
// You can use only one asterisk (*) as a wildcard character for AllowedOrigins and AllowedMethods in a CORS rule. The asterisk (*) wildcard character specifies that all origins or operations are allowed.
corRule.setAllowedMethods(allowedMethod);
corRule.setAllowedOrigins(allowedOrigin);
// AllowedHeaders and ExposeHeaders do not support wildcard characters.
corRule.setAllowedHeaders(allowedHeader);
corRule.setExposeHeaders(exposedHeader);
// Specify the period of time in which the browser can cache the response for an OPTIONS preflight request for specific resources. Unit: seconds.
corRule.setMaxAgeSeconds(10);
// You can configure up to 10 CORS rules for the bucket.
putCorsRules.add(corRule);
// The existing CORS rules are overwritten.
request.setCorsRules(putCorsRules);
// Specify whether to return the "Vary: Origin" header. If you set this parameter to TRUE, the Vary: Origin header is returned regardless of whether the request is a cross-origin request or whether the cross-origin request is successful. If you set this parameter to False, the Vary: Origin header is not returned.
// request.setResponseVary(Boolean.TRUE);
ossClient.setBucketCORS(request);
} catch (OSSException oe) {
System.out.println("Caught an OSSException, which means your request made it to OSS, "
+ "but was rejected with an error response for some reason.");
System.out.println("Error Message:" + oe.getErrorMessage());
System.out.println("Error Code:" + oe.getErrorCode());
System.out.println("Request ID:" + oe.getRequestId());
System.out.println("Host ID:" + oe.getHostId());
} catch (ClientException ce) {
System.out.println("Caught an ClientException, which means the client encountered "
+ "a serious internal problem while trying to communicate with OSS, "
+ "such as not being able to access the network.");
System.out.println("Error Message:" + ce.getMessage());
} finally {
if (ossClient != null) {
ossClient.shutdown();
}
}
}
}
CORSルールの照会
次のサンプルコードは、特定のバケットのCORSルールを照会する方法の例を示しています。
import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.SetBucketCORSRequest;
import java.util.ArrayList;
public class Demo {
public static void main(String[] args) throws Exception {
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint.
String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
// Specify the name of the bucket. Example: examplebucket.
String bucketName = "examplebucket";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
String region = "cn-hangzhou";
// Create an OSSClient instance.
ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
OSS ossClient = OSSClientBuilder.create()
.endpoint(endpoint)
.credentialsProvider(credentialsProvider)
.clientConfiguration(clientBuilderConfiguration)
.region(region)
.build();
try {
ArrayList<SetBucketCORSRequest.CORSRule> corsRules;
// Query the CORS rules.
corsRules = (ArrayList<SetBucketCORSRequest.CORSRule>) ossClient.getBucketCORSRules(bucketName);
for (SetBucketCORSRequest.CORSRule rule : corsRules) {
for (String allowedOrigin1 : rule.getAllowedOrigins()) {
// Query the origins from which cross-origin requests are allowed.
System.out.println(allowedOrigin1);
}
for (String allowedMethod1 : rule.getAllowedMethods()) {
// Query the HTTP methods that cross-origin requests are allowed to use.
System.out.println(allowedMethod1);
}
if (rule.getAllowedHeaders().size() > 0){
for (String allowedHeader1 : rule.getAllowedHeaders()) {
// Query the response headers that are included in the cross-origin requests.
System.out.println(allowedHeader1);
}
}
if (rule.getExposeHeaders().size() > 0) {
for (String exposeHeader : rule.getExposeHeaders()) {
// Query the response headers for allowed access requests from applications.
System.out.println(exposeHeader);
}
}
if ( null != rule.getMaxAgeSeconds()) {
System.out.println(rule.getMaxAgeSeconds());
}
}
} catch (OSSException oe) {
System.out.println("Caught an OSSException, which means your request made it to OSS, "
+ "but was rejected with an error response for some reason.");
System.out.println("Error Message:" + oe.getErrorMessage());
System.out.println("Error Code:" + oe.getErrorCode());
System.out.println("Request ID:" + oe.getRequestId());
System.out.println("Host ID:" + oe.getHostId());
} catch (ClientException ce) {
System.out.println("Caught an ClientException, which means the client encountered "
+ "a serious internal problem while trying to communicate with OSS, "
+ "such as not being able to access the network.");
System.out.println("Error Message:" + ce.getMessage());
} finally {
if (ossClient != null) {
ossClient.shutdown();
}
}
}
}
CORS ルールの削除
次のサンプルコードは、特定のバケットのすべてのCORSルールを削除する方法の例を示しています。
import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
public class Demo {
public static void main(String[] args) throws Exception {
// In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint.
String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
// Specify the name of the bucket. Example: examplebucket.
String bucketName = "examplebucket";
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou.
String region = "cn-hangzhou";
// Create an OSSClient instance.
ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);
OSS ossClient = OSSClientBuilder.create()
.endpoint(endpoint)
.credentialsProvider(credentialsProvider)
.clientConfiguration(clientBuilderConfiguration)
.region(region)
.build();
try {
// Delete all CORS rules of the bucket.
ossClient.deleteBucketCORSRules(bucketName);
} catch (OSSException oe) {
System.out.println("Caught an OSSException, which means your request made it to OSS, "
+ "but was rejected with an error response for some reason.");
System.out.println("Error Message:" + oe.getErrorMessage());
System.out.println("Error Code:" + oe.getErrorCode());
System.out.println("Request ID:" + oe.getRequestId());
System.out.println("Host ID:" + oe.getHostId());
} catch (ClientException ce) {
System.out.println("Caught an ClientException, which means the client encountered "
+ "a serious internal problem while trying to communicate with OSS, "
+ "such as not being able to access the network.");
System.out.println("Error Message:" + ce.getMessage());
} finally {
if (ossClient != null) {
ossClient.shutdown();
}
}
}
}
関連ドキュメント
CORSルールの管理に使用される完全なサンプルコードについては、『GitHub』をご参照ください。
CORSルールを設定するために呼び出すことができるAPI操作の詳細については、「PutBucketCors」をご参照ください。
CORSルールを照会するために呼び出すAPI操作の詳細については、「GetBucketCors」をご参照ください。
CORSルールを削除するために呼び出すことができるAPI操作の詳細については、「DeleteBucketCors」をご参照ください。