# 使用临时URL进行授权访问
![](https://support.huaweicloud.com/sdk-android-devg-obs/public_sys-resources/notice_3.0-zh-cn.png)
开发过程中，您有任何问题可以在github上[提交issue](https://github.com/huaweicloud/huaweicloud-sdk-java-obs/issues)，或者在[华为云对象存储服务论坛](https://bbs.huaweicloud.com/forum/forum-620-1.html)中发帖求助。[接口参考文档](https://obssdk.obs.cn-north-1.myhuaweicloud.com/apidoc/cn/android/index.html)详细介绍了每个接口的参数和使用方法。
OBS客户端支持通过访问密钥、请求方法类型、请求参数等信息生成一个在Query参数中携带鉴权信息的URL，可将该URL提供给其他用户进行临时访问。在生成URL时，您需要指定URL的有效期来限制访客用户的访问时长。
如果您想授予其他用户对桶或对象临时进行其他操作的权限（例如上传或下载对象），则需要生成带对应请求的URL后（例如使用生成PUT请求的URL上传对象），将该URL提供给其他用户。
通过该方式可支持的操作以及相关信息见下表：
| **操作名**   | **HTTP请求方法（OBS **Android**SDK对应值）** | **特殊操作符（OBS Android SDK对应值）**  | **是否需要桶名** | **是否需要对象名** |
|:---|:---|:---|:---|:---|
| 创建桶       | HttpMethodEnum.PUT                  | N/A                            | 是          | 否           |
| 获取桶列表     | HttpMethodEnum.GET                  | N/A                            | 否          | 否           |
| 删除桶       | HttpMethodEnum.DELETE               | N/A                            | 是          | 否           |
| 列举桶内对象    | HttpMethodEnum.GET                  | N/A                            | 是          | 否           |
| 列举桶内多版本对象 | HttpMethodEnum.GET                  | SpecialParamEnum.VERSIONS      | 是          | 否           |
| 列举分段上传任务  | HttpMethodEnum.GET                  | SpecialParamEnum.UPLOADS       | 是          | 否           |
| 获取桶元数据    | HttpMethodEnum.HEAD                 | N/A                            | 是          | 否           |
| 获取桶区域位置   | HttpMethodEnum.GET                  | SpecialParamEnum.LOCATION      | 是          | 否           |
| 获取桶存量信息   | HttpMethodEnum.GET                  | SpecialParamEnum.STORAGEINFO   | 是          | 否           |
| 设置桶配额     | HttpMethodEnum.PUT                  | SpecialParamEnum.QUOTA         | 是          | 否           |
| 获取桶配额     | HttpMethodEnum.GET                  | SpecialParamEnum.QUOTA         | 是          | 否           |
| 设置桶存储类型   | HttpMethodEnum.PUT                  | SpecialParamEnum.STORAGEPOLICY | 是          | 否           |
| 获取桶存储类型   | HttpMethodEnum.GET                  | SpecialParamEnum.STORAGEPOLICY | 是          | 否           |
| 设置桶ACL    | HttpMethodEnum.PUT                  | SpecialParamEnum.ACL           | 是          | 否           |
| 获取桶ACL    | HttpMethodEnum.GET                  | SpecialParamEnum.ACL           | 是          | 否           |
| 开启/关闭桶日志  | HttpMethodEnum.PUT                  | SpecialParamEnum.LOGGING       | 是          | 否           |
| 查看桶日志     | HttpMethodEnum.GET                  | SpecialParamEnum.LOGGING       | 是          | 否           |
| 设置桶策略     | HttpMethodEnum.PUT                  | SpecialParamEnum.POLICY        | 是          | 否           |
| 查看桶策略     | HttpMethodEnum.GET                  | SpecialParamEnum.POLICY        | 是          | 否           |
| 删除桶策略     | HttpMethodEnum.DELETE               | SpecialParamEnum.POLICY        | 是          | 否           |
| 设置生命周期规则  | HttpMethodEnum.PUT                  | SpecialParamEnum.LIFECYCLE     | 是          | 否           |
| 查看生命周期规则  | HttpMethodEnum.GET                  | SpecialParamEnum.LIFECYCLE     | 是          | 否           |
| 删除生命周期规则  | HttpMethodEnum.DELETE               | SpecialParamEnum.LIFECYCLE     | 是          | 否           |
| 设置托管配置    | HttpMethodEnum.PUT                  | SpecialParamEnum.WEBSITE       | 是          | 否           |
| 查看托管配置    | HttpMethodEnum.GET                  | SpecialParamEnum.WEBSITE       | 是          | 否           |
| 清除托管配置    | HttpMethodEnum.DELETE               | SpecialParamEnum.WEBSITE       | 是          | 否           |
| 设置桶多版本状态  | HttpMethodEnum.PUT                  | SpecialParamEnum.VERSIONING    | 是          | 否           |
| 查看桶多版本状态  | HttpMethodEnum.GET                  | SpecialParamEnum.VERSIONING    | 是          | 否           |
| 设置跨域规则    | HttpMethodEnum.PUT                  | SpecialParamEnum.CORS          | 是          | 否           |
| 查看跨域规则    | HttpMethodEnum.GET                  | SpecialParamEnum.CORS          | 是          | 否           |
| 删除跨域规则    | HttpMethodEnum.DELETE               | SpecialParamEnum.CORS          | 是          | 否           |
| 设置桶标签     | HttpMethodEnum.PUT                  | SpecialParamEnum.TAGGING       | 是          | 否           |
| 查看桶标签     | HttpMethodEnum.GET                  | SpecialParamEnum.TAGGING       | 是          | 否           |
| 删除桶标签     | HttpMethodEnum.DELETE               | SpecialParamEnum.TAGGING       | 是          | 否           |
| 上传对象      | HttpMethodEnum.PUT                  | N/A                            | 是          | 是           |
| 追加上传      | HttpMethodEnum.POST                 | SpecialParamEnum.APPEND        | 是          | 是           |
| 下载对象      | HttpMethodEnum.GET                  | N/A                            | 是          | 是           |
| 复制对象      | HttpMethodEnum.PUT                  | N/A                            | 是          | 是           |
| 删除对象      | HttpMethodEnum.DELETE               | N/A                            | 是          | 是           |
| 批量删除对象    | HttpMethodEnum.POST                 | SpecialParamEnum.DELETE        | 是          | 是           |
| 获取对象属性    | HttpMethodEnum.HEAD                 | N/A                            | 是          | 是           |
| 设置对象ACL   | HttpMethodEnum.PUT                  | SpecialParamEnum.ACL           | 是          | 是           |
| 查看对象ACL   | HttpMethodEnum.GET                  | SpecialParamEnum.ACL           | 是          | 是           |
| 初始化分段上传任务 | HttpMethodEnum.POST                 | SpecialParamEnum.UPLOADS       | 是          | 是           |
| 上传段       | HttpMethodEnum.PUT                  | N/A                            | 是          | 是           |
| 复制段       | HttpMethodEnum.PUT                  | N/A                            | 是          | 是           |
| 列举已上传的段   | HttpMethodEnum.GET                  | N/A                            | 是          | 是           |
| 合并段       | HttpMethodEnum.POST                 | N/A                            | 是          | 是           |
| 取消分段上传任务  | HttpMethodEnum.DELETE               | N/A                            | 是          | 是           |
| 恢复归档存储对象  | HttpMethodEnum.POST                 | SpecialParamEnum.RESTORE       | 是          | 是           |
   
通过OBS Android SDK生成临时URL访问OBS的步骤如下：
1. 通过ObsClient.createTemporarySignature生成带签名信息的URL。
2. 使用任意HTTP库发送HTTP/HTTPS请求，访问OBS服务。
![](https://support.huaweicloud.com/sdk-android-devg-obs/public_sys-resources/caution_3.0-zh-cn.png)
如果遇到跨域报错、签名不匹配问题，请参考以下步骤排查问题：
1. 未配置跨域，需要在控制台配置CORS规则，请参考[配置桶允许跨域请求](https://support.huaweicloud.com/sdk-browserjs-devg-obs/obs_24_0107.html)。
2. 签名计算问题，请参考[URL中携带签名](https://support.huaweicloud.com/api-obs/obs_04_0011.html)排查签名参数是否正确；比如上传对象功能，后端将Content-Type参与计算签名生成授权URL，但是前端使用授权URL时没有设置Content-Type字段或者传入错误的值，此时会出现跨域错误。解决方案为：Content-Type字段前后端保持一致。
 
以下代码展示了如何使用临时URL进行授权访问，包括：创建桶、上传对象、下载对象、列举对象、删除对象。
#### 创建桶
```
// 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量ACCESS_KEY_ID和SECRET_ACCESS_KEY_ID。
// 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.html
String ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// 创建ObsClient实例
ObsClient obsClient = new ObsClient(ak, sk, endPoint);
// URL有效期，3600秒
long expireSeconds = 3600L;
TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.PUT, expireSeconds);
request.setBucketName("bucketname");
TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
Log.i("CreateTemporarySignature", "Creating bucket using temporary signature url:");
Log.i("CreateTemporarySignature", "\t" + response.getSignedUrl());
Request.Builder builder = new Request.Builder();
for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
       builder.header(entry.getKey(), entry.getValue());
}
// 使用PUT请求创建桶
String location = "your bucket location";
Request httpRequest = builder.url(response.getSignedUrl()).put(RequestBody.create(null, "<CreateBucketConfiguration><LocationConstraint>" + location + "</LocationConstraint></CreateBucketConfiguration>".getBytes())).build();
OkHttpClient httpClient = new OkHttpClient.Builder().followRedirects(false).retryOnConnectionFailure(false)
              .cache(null).build();
Call c = httpClient.newCall(httpRequest);
Response res = c.execute();
Log.i("CreateTemporarySignature", "\tStatus:" + res.code());
if (res.body() != null) {
       Log.i("CreateTemporarySignature", "\tContent:" + res.body().string() + "\n");
}
res.close();
```
#### 上传对象
```
// 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量ACCESS_KEY_ID和SECRET_ACCESS_KEY_ID。
// 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.html
String ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// 创建ObsClient实例
ObsClient obsClient = new ObsClient(ak, sk, endPoint);
// URL有效期，3600秒
long expireSeconds = 3600L;
Map<String, String> headers = new HashMap<String, String>();
String contentType = "text/plain";
headers.put("Content-Type", contentType);
TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.PUT, expireSeconds);
request.setBucketName("bucketname");
request.setObjectKey("objectname");
request.setHeaders(headers);
TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
Log.i("CreateTemporarySignature", "Creating object using temporary signature url:");
Log.i("CreateTemporarySignature", "\t" + response.getSignedUrl());
Request.Builder builder = new Request.Builder();
for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
       builder.header(entry.getKey(), entry.getValue());
}
//使用PUT请求上传对象
Request httpRequest = builder.url(response.getSignedUrl()).put(RequestBody.create(MediaType.parse(contentType), "Hello OBS".getBytes("UTF-8"))).build();
OkHttpClient httpClient = new OkHttpClient.Builder().followRedirects(false).retryOnConnectionFailure(false)
              .cache(null).build();
Call c = httpClient.newCall(httpRequest);
Response res = c.execute();
Log.i("CreateTemporarySignature", "\tStatus:" + res.code());
if (res.body() != null) {
       Log.i("CreateTemporarySignature", "\tContent:" + res.body().string() + "\n");
}
res.close();
```
#### 下载对象
```
// 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量ACCESS_KEY_ID和SECRET_ACCESS_KEY_ID。
// 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.html
String ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// 创建ObsClient实例
ObsClient obsClient = new ObsClient(ak, sk, endPoint);
// URL有效期，3600秒
long expireSeconds = 3600L;
TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.GET, expireSeconds);
request.setBucketName("bucketname");
request.setObjectKey("objectname");
TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
Log.i("CreateTemporarySignature", "Getting object using temporary signature url:");
Log.i("CreateTemporarySignature", "\t" + response.getSignedUrl());
Request.Builder builder = new Request.Builder();
for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
       builder.header(entry.getKey(), entry.getValue());
}
//使用GET请求下载对象
Request httpRequest = builder.url(response.getSignedUrl()).get().build();
OkHttpClient httpClient = new OkHttpClient.Builder().followRedirects(false).retryOnConnectionFailure(false)
              .cache(null).build();
Call c = httpClient.newCall(httpRequest);
Response res = c.execute();
Log.i("CreateTemporarySignature", "\tStatus:" + res.code());
if (res.body() != null) {
       Log.i("CreateTemporarySignature", "\tContent:" + res.body().string() + "\n");
}
res.close();
```
#### 列举对象
```
// 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量ACCESS_KEY_ID和SECRET_ACCESS_KEY_ID。
// 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.html
String ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// 创建ObsClient实例
ObsClient obsClient = new ObsClient(ak, sk, endPoint);
// URL有效期，3600秒
long expireSeconds = 3600L;
TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.GET, expireSeconds);
request.setBucketName("bucketname");
TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
Log.i("CreateTemporarySignature", "Getting object list using temporary signature url:");
Log.i("CreateTemporarySignature", "\t" + response.getSignedUrl());
Request.Builder builder = new Request.Builder();
for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
       builder.header(entry.getKey(), entry.getValue());
}
//使用GET请求获取对象列表
Request httpRequest = builder.url(response.getSignedUrl()).get().build();
OkHttpClient httpClient = new OkHttpClient.Builder().followRedirects(false).retryOnConnectionFailure(false)
              .cache(null).build();
Call c = httpClient.newCall(httpRequest);
Response res = c.execute();
Log.i("CreateTemporarySignature", "\tStatus:" + res.code());
if (res.body() != null) {
       Log.i("CreateTemporarySignature", "\tContent:" + res.body().string() + "\n");
}
res.close();
```
#### 删除对象
```
// 认证用的ak和sk硬编码到代码中或者明文存储都有很大的安全风险，建议在配置文件或者环境变量中密文存放，使用时解密，确保安全；本示例以ak和sk保存在环境变量中为例，运行本示例前请先在本地环境中设置环境变量ACCESS_KEY_ID和SECRET_ACCESS_KEY_ID。
// 您可以登录访问管理控制台获取访问密钥AK/SK，获取方式请参见https://support.huaweicloud.com/usermanual-ca/ca_01_0003.html
String ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// 创建ObsClient实例
ObsClient obsClient = new ObsClient(ak, sk, endPoint);
// URL有效期，3600秒
long expireSeconds = 3600L;
TemporarySignatureRequest request = new TemporarySignatureRequest(HttpMethodEnum.DELETE, expireSeconds);
request.setBucketName("bucketname");
request.setObjectKey("objectname");
TemporarySignatureResponse response = obsClient.createTemporarySignature(request);
Log.i("CreateTemporarySignature", "Deleting object using temporary signature url:");
Log.i("CreateTemporarySignature", "\t" + response.getSignedUrl());
Request.Builder builder = new Request.Builder();
for (Map.Entry<String, String> entry : response.getActualSignedRequestHeaders().entrySet()) {
       builder.header(entry.getKey(), entry.getValue());
}
//使用DELETE删除对象
Request httpRequest = builder.url(response.getSignedUrl()).delete().build();
OkHttpClient httpClient = new OkHttpClient.Builder().followRedirects(false).retryOnConnectionFailure(false)
              .cache(null).build();
Call c = httpClient.newCall(httpRequest);
Response res = c.execute();
Log.i("CreateTemporarySignature", "\tStatus:" + res.code());
if (res.body() != null) {
       Log.i("CreateTemporarySignature", "\tContent:" + res.body().string() + "\n");
}
res.close();
```
![](https://support.huaweicloud.com/sdk-android-devg-obs/public_sys-resources/note_3.0-zh-cn.png)
HttpMethodEnum是OBS Android SDK定义的枚举类型，代表请求方法类型。