阿里云RAM产品实在是太烂，根本就不知道该如何用

写了那么多，看了好多天，实在看不懂到底在讲些什么，根本就没讲到重点，demo代码也写得太烂：


关于RAM的STS，代码不断变化，版本号同样是2015-04-01的调用代码，结果aliyun-java-sdk-sts-2.1.0和aliyun-java-sdk-sts-2.1.6的代码根本就没有任何联系，下载下来的PDF说明也是一样。


以下是aliyun_java_sdk_sts_20150825的demo代码，一点说明都没有，这就是demo？使劲地去翻看你们的文档，一直就找不到roleSessionName到底是什么鬼，可能实在是在下太过蠢笨了吧，这么高深的代码一点都看不懂。另外，一篇求助文章，发表了好几天了，结果回复一直为0（除了我自己）！收费倒是收的很勤，看来大概是店大要欺客了吧~

import com.aliyuncs.DefaultAcsClient;
import com.aliyuncs.exceptions.ClientException;
import com.aliyuncs.http.MethodType;
import com.aliyuncs.http.ProtocolType;
import com.aliyuncs.profile.DefaultProfile;
import com.aliyuncs.profile.IClientProfile;
import com.aliyuncs.sts.model.v20150401.AssumeRoleRequest;
import com.aliyuncs.sts.model.v20150401.AssumeRoleResponse;


public class StsServiceSample {
  public static final String REGION_CN_HANGZHOU = "cn-hangzhou";
  public static final String STS_API_VERSION = "2015-04-01";
  public static final String STS_VERSION = "1";


  static AssumeRoleResponse assumeRole(String accessKeyId, String accessKeySecret,
                                       String roleArn, String roleSessionName, String policy, ProtocolType protocolType) throws ClientException {
    try {
      IClientProfile profile = DefaultProfile.getProfile(REGION_CN_HANGZHOU, accessKeyId, accessKeySecret);
      DefaultAcsClient client = new DefaultAcsClient(profile);


      final AssumeRoleRequest request = new AssumeRoleRequest();
      request.setVersion(STS_API_VERSION);
      request.setMethod(MethodType.POST);
      request.setProtocol(protocolType);


      request.setRoleArn(roleArn);
      request.setRoleSessionName(roleSessionName);
      request.setPolicy(policy);


      final AssumeRoleResponse response = client.getAcsResponse(request);


      return response;
    } catch (ClientException e) {
      throw e;
    }
  }
  public static void main(String[] args) {
    String accessKeyId = "o************F";
    String accessKeySecret = "y*******************U";
    String roleArn = "acs:ram::145883****900618:role/ossadminrole";
    String roleSessionName = "alice";
    String policy = "{\n" +
            "    \"Version\": \"1\", \n" +
            "    \"Statement\": [\n" +
            "        {\n" +
            "            \"Action\": [\n" +
            "                \"oss:GetBucket\", \n" +
            "                \"oss:GetObject\" \n" +
            "            ], \n" +
            "            \"Resource\": [\n" +
            "                \"acs:oss:*:177530****529849:mybucket\", \n" +
            "                \"acs:oss:*:177530****529849:mybucket/*\" \n" +
            "            ], \n" +
            "            \"Effect\": \"Allow\"\n" +
            "        }\n" +
            "    ]\n" +
            "}";
    ProtocolType protocolType = ProtocolType.HTTPS;


    try {
      final AssumeRoleResponse response = assumeRole(accessKeyId, accessKeySecret,
              roleArn, roleSessionName, policy, protocolType);


      System.out.println("Expiration: " + response.getCredentials().getExpiration());
      System.out.println("Access Key Id: " + response.getCredentials().getAccessKeyId());
      System.out.println("Access Key Secret: " + response.getCredentials().getAccessKeySecret());
      System.out.println("Security Token: " + response.getCredentials().getSecurityToken());
    } catch (ClientException e) {
      System.out.println("Failed to get a federation token.");
      System.out.println("Error code: " + e.getErrCode());
      System.out.println("Error message: " + e.getErrMsg());
    }


  }
}